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Assessment of forage species and varieties for the central interior of British Columbia McNeil, Allan Osborne 1987

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ASSESSMENT OF FORAGE SPECIES AND VARIETIES FOR THE CENTRAL INTERIOR OF BRITISH COLUMBIA by ALLAN OSBORNE MCNEIL B. Sc. ( A g r . ) , The U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1978.  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN THE FACULTY OF GRADUATE STUDIES (Animal Science)  We a c c e p t t h i s t h e s i s as conforming to t h e r e q u i r e d  standard  THE UNIVERSITY OF BRITISH COLUMBIA NOVEMBER 1986 if?)ALLAN OSBORNE MCNEIL, 1986  .3 2  In presenting an  this thesis i n p a r t i a l fulfillment  advanced degree a t  the  Library  further  this  agree t h a t  be  for financial  gain  Vancouver, Canada V6T  1Y3  the head of my  s h a l l not  U n i v e r s i t y of B r i t i s h Columbia Main M a l l  c o p y i n g of  this  study.  that I  thesis  for  department or by  his  I t i s u n d e r s t o o d t h a t c o p y i n g or p u b l i c a t i o n of  Department of A n i m a l S c i e n c e  1956  B r i t i s h C o l u m b i a , I agree  a v a i l a b l e f o r r e f e r e n c e and  g r a n t e d by  permission.  The  of  permission for extensive  representatives.  thesis  University  s h a l l make i t f r e e l y  s c h o l a r l y purposes may or her  the  of the r e q u i r e m e n t s f o r  be  a l l o w e d w i t h o u t my  written  ABSTRACT  1982 experiments quality  were conducted  i n relation  to animal  t o examine s e v e r a l a s p e c t s o f f o r a g e  nutrition,  including  the d i f f e r e n c e s i n  q u a l i t y between f o r a g e t y p e s (legumes o r g r a s s e s ) , s p e c i e s and v a r i e t i e s ; between y e a r s ; between two hay m i x e s ; and between t h r e e h a r v e s t In the  a d d i t i o n , t h e importance first  experiment,  dates.  o f q u a l i t y r e l a t i v e t o y i e l d i s examined.  acid  detergent  fibre,  n e u t r a l detergent  crude p r o t e i n , and n y l o n bag d r y m a t t e r d i s a p p e a r a n c e  In  fibre,  d e t e r m i n a t i o n s were  used t o a s s e s s t h e v a r i a t i o n i n q u a l i t y between f o r a g e t y p e s , s p e c i e s and v a r i e t i e s , and between y e a r s . and  digestibility  I n t h e second, v o l u n t a r y d r y m a t t e r i n t a k e  r e s u l t s were used  between hay mixes and h a r v e s t  to assess  the v a r i a t i o n  i n quality  dates.  The r e s u l t s o f the f i r s t  experiment  i n d i c a t e t h a t the legumes were  of h i g h e r q u a l i t y than t h e g r a s s e s ; r e d and a l s i k e c l o v e r were of h i g h e r quality  than  alfalfa,  timothy.  With  varieties  were  difference detergent forages  and  orchardgrass  of  higher  quality  t h e e x c e p t i o n o f r e d c l o v e r s , where L a k e l a n d of  higher  i n quality  quality  between  than  varieties  f i b r e a n a l y s i s r e s u l t s suggest grown  was  i n different  years  while  Altaswede, within  a  there  and P a c i f i c was  species.  The  difference  in  results quality  of  the  second  between  acid  detergent  experiment  forage  little Neutral  a d i f f e r e n c e i n i n t a k e between fibre analysis  r e s u l t s i n d i c a t e no d i f f e r e n c e i n d i g e s t i b i l i t y would be expected years.  than  mixtures  indicate (the  there  early  between was  a  maturing  m i x t u r e was b e s t ) , and h a r v e s t s ( e a r l y and mid bloom h a r v e s t s were b e t t e r t h a n t h e l a t e bloom h a r v e s t ) . The parameter w i t h t h e l a r g e s t v a r i a b i l i t y was y i e l d .  Differences  were g r e a t e r between y e a r s than between t y p e s and s p e c i e s ( t h e c l o v e r s highest, a l f a l f a  and t i m o t h y i n t e r m e d i a t e , and o r c h a r d g r a s s l o w e s t ) w i t h  the l e a s t v a r i a t i o n o c c u r i n g between v a r i e t i e s w i t h i n s p e c i e s . clover-timothy  ( l a t e maturing)  f o r a g e m i x t u r e was  The r e d  the h i g h e s t y i e l d i n g .  W i t h i n f o r a g e m i x t u r e s t h e f u l l bloom h a r v e s t (100% bloom o f t h e legume component) had t h e h i g h e s t y i e l d s . S i n c e y i e l d was more v a r i a b l e than the q u a l i t y parameters i t was  concluded  t h a t t h e most i m p o r t a n t c o n s i d e r a t i o n when s e l e c t i n g a  f o r a g e m i x t u r e was y i e l d . quality  studied,  parameters  between  S i n c e t h e r e tended t o be l i t t l e d i f f e r e n c e i n varieties  within  a  species, selecting  the  h i g h e s t y i e l d i n g c o m b i n a t i o n would p r o v i d e the l a r g e s t amount o f u s e a b l e n u t r i e n t s p e r h e c t a r e o f l a n d base.  TABLE OF CONTENTS  ABSTRACT TABLE OF CONTENTS LIST OF TABLES ACKNOWLEDGEMENTS  i i iv v i viii  CHAPTER 1 - INTRODUCTION CHAPTER 2 - LITERATURE REVIEW 2.1 FACTORS AFFECTING FEED INTAKE 2.1.1 INTAKE REGULATION 2.1.2 ANIMAL FACTORS AFFECTING INTAKE 2.1.3 PLANT FACTORS AFFECTING INTAKE 2.1.3.1 FORAGE TYPE, SPECIES AND VARIETY 2.1.3.2 PLANT MATURITY AND DATE OF CUTTING 2.1.3.3 CHEMICAL COMPOSITION 2.1.3.4 LEAF AND STEM 2.1.3.5 CHOPPING AND PELLETING 2.2  FACTORS AFFECTING FEED DIGESTIBILITY 2.2.1 ANIMAL FACTORS AFFECTING DIGESTIBILITY 2.2.2 PLANT FACTORS AFFECTING DIGESTIBILITY 2.2.2.1 FORAGE TYPE, SPECIES AND VARIETY 2.2.2.2 PLANT MATURITY AND DATE OF CUTTING 2.2.2.3 LEAF AND STEM 2.2.2.4 CHOPPING AND PELLETING 2.2.2.5  CHEMICAL TREATMENTS  1  3 3 5 7 8 9 10 12 12 13 13 14 14 16 17 17 18  2.3  ENVIRONMENTAL FACTORS AFFECTING INTAKE AND DIGESTIBILITY.18  2.4  TROPICAL VERSUS TEMPERATE GRASSES  20  2.5  LABORATORY METHODS OF ASSESSING FORAGE VALUE 2.5.1 PROXIMATE ANALYSIS 2.5.2 IN VITRO DRY MATTER DISAPPEARANCE 2.5.3 NYLON BAG DRY MATTER DISAPPEARANCE 2.5.4 CHEMICAL SYSTEMS 2.5.4.1 VAN SOEST FIBRE SYSTEM 2.5.4.2 FONNESBECK SYSTEM 2.5.4.3 SOUTHGATE SYSTEM SHEEP AS MODELS FOR CATTLE  21 21 23 24 28 28 33 34 35  2.6  CHAPTER 3 - THE VARIETY TRIAL 3.1 MATERIALS AND METHODS 3.1.2 DETERMINATIONS 3.1.1 EXPERIMENTAL DESIGN AND STATISTICAL ANALYSIS  36 39 41  3.2  3.3  3.1.3 ASSESSMENT OF FEEDING VALUE 45 3.1.4 INTEGRATION OF FORAGE QUALITY AND YIELD 45 RESULTS 46 3.2.1 YIELD ...46 3.2.2 CRUDE PROTEIN 50 3.2.3 NEUTRAL DETERGENT FIBRE 54 3.2.4 ACID DETERGENT FIBRE 58 3.2.5 NYLON BAG DRY MATTER DISAPPEARANCE 62 3.2.6 ASSESSMENT OF FEEDING VALUE 68 3.2.7 INTEGRATION OF FORAGE QUALITY AND YIELD 70 3.2.8 NBDMD RESULTS USING PLOTS OF ANIMALS AS REPLICATES..73 3.2.9 WEATHER 76 DISCUSSION 78 3.3.1 YIELD 78 3.3.2 QUALITY DETERMINATIONS 80 3.3.3 ASSESSMENT OF FORAGE QUALITY 86 3.3.4 ASSESSMENT OF FEEDING VALUE 88 3.3.5 INTEGRATION OF FORAGE QUALITY AND YIELD 89 3.3.6 NBDMD RESULTS USING PLOTS OR ANIMALS AS REPLICATES..90  CHAPTER 4 - THE FEEDING TRIAL 4.1 MATERIALS AND METHODS 4.1.1 FORAGES 4.1.2 EXPERIMENTAL DESIGN AND STATISITCAL ANALYSIS 4.1.3 INTAKE AND DIGESTIBILITY TRIAL METHODOLOGY 4.1.4 ANIMAL MANAGEMENT 4.1.5 ANALYTICAL PROCEDURES  91 91 93 94 95 95  4.2  RESULTS  96  4.3  DISCUSSION 4.3.1 INTAKE AND DIGESTIBILITY 4.3.2 UNCONTROLLED FACTORS 4.3.3 LINEAR AND QUADRATIC REGRESSION ANALYSIS 4.3.4 INTEGRATING RESULTS WITH YIELD 4.3.5 COMPARISON WITH VARIETY TRIAL RESULTS  107 107 110 112 113 113  CHAPTER 5 - GENERAL DISCUSSION AND CONCLUSIONS  115  CHAPTER 6 - RECOMMENDATIONS  119  REFERENCES  120  APPENDIX  131  LIST OF TABLES Chapter 3 T a b l e 3.1 T a b l e 3.2 T a b l e 3.3 Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table  S p e c i e s and V a r i e t i e s Used i n T r i a l 37 H a r v e s t Dates f o r Samples o f t h e V a r i e t y T r i a l 38 L e a s t Square Means ± SEM o f Forage Y i e l d s by Type and S p e c i e s 47 3.4 L e a s t Square Means ± SEM o f Forage Y i e l d s by Variety 49 3.5 L e a s t Square Means ± SEM.of Y i e l d , CP, NDF, ADF, and NBDMD by Y e a r 51 3.6 L e a s t Square Means ± SEM o f Crude P r o t e i n L e v e l s by Type and S p e c i e s 52 3.7 L e a s t Square Means ± SEM o f Crude P r o t e i n L e v e l s by V a r i e t y 53 3.8 L e a s t Square Means ± SEM o f N e u t r a l D e t e r g e n t F i b r e L e v e l s by Type and S p e c i e s 55 3.9 L e a s t Square Means ± SEM o f N e u t r a l D e t e r g e n t F i b r e L e v e l s by V a r i e t y 57 3.10 L e a s t Square Means ± SEM of A c i d D e t e r g e n t F i b r e L e v e l s by Type and S p e c i e s 59 3.11 L e a s t Square Means ± SEM o f A c i d D e t e r g e n t F i b r e L e v e l s by V a r i e t y 61 3.12 L e a s t Square Means ± SEM o f N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s by Type and S p e c i e s 63 3.13 L e a s t Square Means ± SEM o f N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s by V a r i e t y 64 3.14 L e a s t Square Means ± SEM o f N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s by Y e a r 66 3.15 L e a s t Square Means ± SEM o f Nylong Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s by A n i m a l 67 3.16 E s t i m a t i o n o f Dry M a t t e r I n t a k e (DMI), D i g e s t i b l e Dry M a t t e r (DDM) and F e e d i n g V a l u e Index (FVI) 69 3.17 L e a s t Square Means ± SEM o f D i g e s t i b l e Energy Y i e l d s by Type and S p e c i e s 71 3.18 L e a s t Square Means ± SEM o f D i g e s t i b l e Energy Y i e l d s by V a r i e t y 72 3.19 L e a s t Square Means ± SEM o f Crude P r o t e i n Y i e l d s by Type and S p e c i e s 74 3.20 L e a s t Square Means ± SEM of Crude P r o t e i n Y i e l d s by V a r i e t y 75 3.21 L e a s t Square Means ± SEM o f N y l o n Bag Dry M a t t e r Disappearance 77 Chapter 4 4.1 H a r v e s t Date and Y i e l d o f T e s t Forages 92 4.2 N u t r i e n t C o m p o s i t i o n o f Hay Mixes (Dry M a t t e r B a s i s ) . . 9 7 4.3 P r o p o r t i o n o f Grass and Legume i n Each Hay M i x 98 4.4 Means o f I n t a k e Parameters f o r E a r l y M a t u r i n g and L a t e M a t u r i n g Forage Mixes 100 4.5 Means o f D i g e s t i b i l i t y Parameters f o r E a r l y M a t u r i n g and L a t e M a t u r i n g Forage Mixes 101  T a b l e 4.6 T a b l e 4.7 T a b l e 4.8 T a b l e 4.9  Means o f I n t a k e Parameters f o r E a r l y , M i d and F u l l Bloom H a r v e s t s . . . 102 Means of D i g e s t i b i l t y Parameters f o r E a r l y , M i d and F u l l Bloom H a r v e s t s 103 C o e f f i c i e n t s of D e t e r m i n a t i o n f o r Simple and M u l t i p l e F a c t o r Models 105 Hay M i x , H a r v e s t Date and Y i e l d o f T e s t F o r a g e s . . . . 106  ACKNOWLEDGEMENTS  I would assistance  like  t o e x p r e s s my a p p r e c i a t i o n  and guidance o v e r  the past three  Canada f o r t h e u s e o f f a c i l i t i e s . Tait  f o r providing  Pelter,  and  acknowledged.  Alberta I  would  Agriculture like  years,  and t o A g r i c u l t u r e  I would a l s o l i k e t o thank D r . M a l c o l m  d i r e c t i o n and a s s i s t a n c e .  J . N. T i n g l e ,  gratefully  t o D r . L y l e Rode f o r h i s  B. Wikeem w i t h  help  t h o u g h t s and r e s o u r c e s  F i n a l l y , I would f o r assistance  Further  like  with  from J . A. was a l s o  t o thank D r . J . Basarab  and s t a t i s t i c a l  t o pay s p e c i a l t r i b u t e t o R e g i n a  analysis.  who has g i v e n  up  h o l i d a y s and weekends t o see t h i s p r o j e c t completed and t o thank h e r f o r her patience  and s u p p o r t t h r o u g h o u t .  CHAPTER 1 INTRODUCTION Agriculture  i n t h e C e n t r a l I n t e r i o r r e g i o n o f B r i t i s h Columbia was  extensive  i n nature  livestock  consumption.  possessing  and was based m a i n l y The i n d u s t r y  i n d i v i d u a l microclimates  sufficiently  from o t h e r  regions  on f o r a g e  was l o c a t e d  with  crops intended f o r along  growing c o n d i t i o n s  t o r e q u i r e l o c a l forage  S e v e r a l p r o j e c t s have been u n d e r t a k e n t o e v a l u a t e varieties 1974;  i n the region  Tingle  (Waldern  and E l l i o t ,  and B u r n s ,  1975; W a l d i e  examined p r o d u c t i v i t y o f s p e c i e s  river  valleys  that  differ  crop  evaluation.  forage  s p e c i e s and  1964; T i n g l e  et_ a l . , 1983).  and Dawley, These  trials  and v a r i e t i e s as measured by y i e l d and  i n v o l v e d few a n i m a l r e l a t e d p a r a m e t e r s .  Additional laboratory  techniques  a r e a v a i l a b l e t h a t f u r t h e r e l u c i d a t e t h e s u i t a b i l i t y o f those s p e c i e s and v a r i e t i e s on t e s t f o r a n i m a l  production.  W i t h t h e s e p o i n t s i n mind t h e o v e r a l l o b j e c t i v e o f t h i s study was t o assess the q u a l i t y of s e l e c t e d forages British  Columbia  information To  i n terms  of animal  upon w h i c h b e t t e r  meet t h i s  objective  grown i n t h e C e n t r a l I n t e r i o r o f production  i n order  to  obtain  l i v e s t o c k recommendations c o u l d be b a s e d . two p r o j e c t s  were u n d e r t a k e n .  The  first  project  (the Variety T r i a l ) involved  a n a l y s i s o f f o u r v a r i e t i e s each o f  orchard  g r a s s ( D a c t y l i s g l o m e r a t a L.) t i m o t h y ( Phleum p r a t e n s e L.) and  alfalfa  ( Medicago s a t i v a L.) , one v a r i e t y o f a l s i k e c l o v e r ( T r i f o l i u m  hybridum L.) and t h r e e v a r i e t i e s o f r e d c l o v e r ( T r i f o l i u m p r a t e n s e L . ) . Samples o f each v a r i e t y were c o l l e c t e d o v e r t h r e e y e a r s as p a r t o f t h e B.C. Seed  Crop  Evaluation  harvested  at  quality.  Standing  Project  the phenological  Determinations  crop  was  carried  (1981-1983).  stage  then  considered  determined  Each  forage  optimum  plot  for  and t h e samples  out i n t h e V a r i e t y  Trial  included  was  forage stored. crude  protein  (CP), a c i d detergent f i b r e  (ADF), n e u t r a l d e t e r g e n t f i b r e  and n y l o n bag d r y m a t t e r d i s a p p e a r a n c e  (NDF),  (NBDMD).  The s p e c i f i c o b j e c t i v e s of the v a r i e t y t r i a l were: 1) t o a s s e s s the v a r i a t i o n i n the n u t r i t i o n a l  quality  between f o r a g e s p e c i e s and v a r i e t i e s w i t h i n s p e c i e s , and; 2) t o a s s e s s t h e v a r i a t i o n i n t h e n u t r i t i o n a l q u a l i t y of f o r a g e s p e c i e s and v a r i e t i e s between y e a r s based  on  l a b o r a t o r y a n a l y t i c a l procedures. The second p r o j e c t (The F e e d i n g T r i a l ) i n v o l v e d an assessment of grass-legume  mixtures  legume component. Toro  timothy  formulation second timothy. each  and  harvested  The  first  Manchar  at  early,  which  Dry m a t t e r  smooth bromegrass  consisted  of  i n t a k e (DMI)  m i x t u r e were d e t e r m i n e d .  and  full  bloom  of  m i x t u r e c o n s i s t e d of T e t r a a l s i k e  i n t e n d e d t o mature e a r l i e r  mixture  mid  Altaswede  and  The  red  season  clover  objectives  of  in a  than and  dry m a t t e r d i g e s t i b i l i t y  specific  the  clover,  ( Bromus i n e r m i s L.)  i n the growing  two  the  Climax (DMD)  of  the f e e d i n g  t r i a l were: 1) t o a s s e s s the e f f e c t of an e a r l y and l a t e m a t u r i n g f o r a g e m i x t u r e on v o l u n t a r y f e e d i n t a k e and  digestibility,  and; 2) to a s s e s s the e f f e c t of i n c r e a s i n g m a t u r i t y of each m i x t u r e on v o l u n t a r y f e e d i n t a k e and  digestibilty.  forage  CHAPTER 2 LITERATURE, REVIEW 2.1  FACTORS AFFECTING FEED INTAKE Ruminant a n i m a l s  are able to convert  p l a n t m a t e r i a l s that are  not  Thus, they not compete d i r e c t l y w i t h  man  w e l l d i g e s t e d by man  i n t o food.  for  (Van S o e s t , 1982).  food rescources  of t h e s e p l a n t m a t e r i a l s was the  constituents  physiological  of  the  state  of  production potential feed  i n t a k e and  determined  feed,  the  The  the  animal  rumen and  utilization.  potential  by a complex i n t e r a c t i o n between  (or feeding value)  feed  animal production  microbial population,  the of  environment. a f o r a g e was  The  animal  a f u n c t i o n of  Apparent d i g e s t i b i l i t y  was  a major  component of f e e d u t i l i z a t i o n ( o r n u t r i t i v e v a l u e ) a l t h o u g h o t h e r such  as  efficiency  1973).  I t was  of n u t r i e n t u t i l i z a t i o n  difficult  the  are a l s o important  t o r e s o l v e the r e l a t i v e importance  factors (Ulyatt,  of v o l u n t a r y  i n t a k e and n u t r i t i v e v a l u e i n d e t e r m i n i n g the o v e r a l l f e e d i n g v a l u e of a f o r a g e because the two being  a  production  (1973) i n d i c a t e d approximately The  f e e d parameters a r e c o r r e l a t e d - n u t r i t i v e  response  per  unit  that d i g e s t i b i l i t y  50Z  intake.  and  The  section  of  the  of U l y a t t  i n t a k e a r e each a s s o c i a t e d w i t h  of the v a r i a t i o n i n l i v e weight  following  results  literature  g a i n of t e s t review  will  animals.  cover  f a c t o r s c o n t r o l l i n g and a f f e c t i n g i n t a k e and d i g e s t i b i l i t y and the r e l a t i o n s h i p between these f e e d q u a l i t y 2.1.1  value  the  inter-  parameters.  INTAKE REGULATION Jones  ruminant  (1972) i n d i c a t e d  feed  intake  i n h i s review  r e g u l a t i o n are  paper t h a t the mechanisms of  complex  and  not  well  understood.  These mechanisms have e v o l v e d so t h a t a c e r t a i n energy b a l a n c e was tained  t h a t v a r i e s w i t h the p r o d u c t i v e s t a t u s of  Della-Fera,  1981).  There i s e v i d e n c e  the a n i m a l  t h a t the p a r t i c u l a r  main-  (Baile  and  physiological  mechanisms c o n t r o l l i n g i n t a k e w i l l  vary  feed.  f e e d consumption w i l l r i s e t o a p o i n t  As d i g e s t i b l i t y i s i n c r e a s e d  depending on  where the a n i m a l s energy r e q u i r e m e n t s are met. is  c o n t r o l l e d by  metabolic  f a c t o r s , and  as  the q u a l i t y of  Above t h i s p o i n t nutritive  value  intake  increases  f u r t h e r f e e d i n t a k e d e c r e a s e s s i n c e l e s s i s r e q u i r e d t o meet the energy b a l a n c e .  with  dairy  cows t h i s  Della-Fera controlling  and  point Bailie  intake  are  events  mediated  chemostatic  Della-Fera, volatile  1981)  v  fatty  are  such  acids  l i m i t intake. was  about 66%  dry  matter  (1984)  indicated  that  the  not  but  well  or  as  in  the  digestibility.  various  hypothalamus but  understood.  thermostatic  osmolarity  other  Conrad (1966) suggested t h a t  at  integrated  neurochemical by  desired  Below the p o i n t where energy r e q u i r e m e n t s are met  f a c t o r s such as "rumen f i l l "  the  of  Feed  "because changes of  the  actual  intake  mechanisms body  factors  fluids,  may  be  (Bailie rumen  hypothalamic  and  pH  and  and  surface  t e m p e r a t u r e s d u r i n g f e e d i n g a r e r e l a t e d more to n o n s p e c i f i c a c t i v i t y  than  t o f e e d i n g t h e r e seems t o be l i t t l e e v i d e n c e t h a t temperature changes per se a c t under most c o n d i t i o n s as a s i g n a l f o r the h u n g e r - s a t i e t y Feed  intake  alimentary  are  reduced  1971).  stretch receptors n a t u r e and The  also  c o n t r o l l e d by  the  t r a c t , the r a t e of d i g e s t i o n and  residues (Bines,  was  in  Physical  s i z e before regulation  they of  physical  capacity  of  the  the r a t e a t w h i c h u n d i g e s t e d can  food  i n the w a l l s of the rumen and  move intake  out  of  the  probably  rumen c a p a c i t y  Della-Fera, i s the  rumen  involves  i n t e s t i n e s but the  l o c a t i o n of t h e s e a r e not known ( B a i l e and  p r i n c i p l e f a c t o r determining  system".  exact 1981).  s i z e of  a n i m a l ( B i n e s , 1971), t h u s , when food of r e l a t i v e l y low d i g e s t i b i l i t y provided from  the  animal intake i s broadly total  tract also  r e l a t e d to l i v e w e i g h t .  a f f e c t s intake  ( M e i j s , 1981).  the is  Disappearance The  rate  of  disappearance  of  breakdown by  the  activity; gut.  digesta  from  a c t i o n of  the  rumen was  function  both m i c r o b i a l fermentation  i n c l u d i n g chewing, r u m i n a t i o n  The  a  r e l a t i o n s h i p between  intake  of  and  rate  mechanical  and m u s c u l a r c o n t r a c t i o n of and  digesta  r e f l e c t e d i n the r e l a t i o n s h i p between v o l u n t a r y  disappearance  i n t a k e and  of  the was  digestibility  of v a r i o u s roughages. Meijs  (1981)  concluded  there  d i g e s t i b i l i t y and f e e d i n t a k e .  The  moves from p h y s i c a l t o m e t a b o l i c  was  a  strong  r e l a t i o n s h i p between  p o i n t at w h i c h food i n t a k e r e g u l a t i o n f a c t o r s depends on  p h y s i o l o g i c a l s t a t u s of the a n i m a l and  the  type of  feed,  the energy c o n c e n t r a t i o n per u n i t  of d i e t volume.  2.1.2  ANIMAL FACTORS AFFECTING INTAKE W h i l e a n i m a l i n t a k e i s r e g u l a t e d by p h y s i c a l and m e t a b o l i c  other  factors  lactation, important  such  as  pregnancy, p a r t i n how  sensory body  cues,  sex,  composition  much was  and  weight,  exercise  also  breed, play  an  consumed.  Ruminant a n i m a l s used s e n s o r y c l u e s and  and  age  factors,  including gustatory, olfactory  t a c t i l e s t i m u l a t i o n but not v i s i o n f o r s e l e c t i o n of f e e d s i n c e sheep  fitted sheep  with  b l i n d e r s had  ( B a i l e and  shown by  Arnold  the  same f e e d  F o r b e s , 1974).  preference  E v i d e n c e of  ranking  as  sighted  the o l f a c t o r y e f f e c t s  et a l . (1980) i n w h i c h the v o l u n t a r y  was  i n t a k e of hay  by  normal sheep was  s i g n i f i c a n t l y i n c r e a s e d by the odor of b u t y r i c a c i d  and  amyl a c e t a t e and  d e p r e s s e d by  sheep were u n a f f e c t e d for  and  those compounds t e s t e d .  r e j e c t i o n of f e c e s  the odor of coumarin and  o v e r a l l had  higher  intakes  glycine.  Anosmic  than normal sheep  F u r t h e r e v i d e n c e of the e f f e c t of s m e l l  contaminated herbage by  cattle  ( M e i j s , 1981).  was  Other  researchers high  have n o t e d t h a t i n t a k e was  percentage  of  fine  reduced when the r a t i o n c o n t a i n s  particles.  Part  of  a t t r i b u t e d t o reduced p a l a t a b i l i t y of the f e e d Aderibigbe related  differences  ryegrass. in  et_ a l .  deer  Sex  in  (1982) the  speculated  animal's  sodium a c e t a t e  1979)  where b u c k s  than does.  i n t a k e of beef s t e e r s was  (Van  that  reduction  may  be  animal  sex  S o e s t , 1982).  there  preference  d i f f e r e n c e s i n preference  (Church,  this  for  were four  v a r i e t i e s of  were seen i n s e v e r a l  showed  a  a  stronger  instances  preference  for  Owens et a l . (1985) found t h a t o v e r a l l f e e d 2.8%  higher  than beef h e i f e r s i n a s t u d y of  745  d i f f e r e n t s e t s of pens of 50 c a t t l e o r more. Owens et^ a l . (1985) found t h a t b r e e d had dairy  breed  steers  d i f f e r e n c e of 17% due  eating  during  more  each 28  than day  t o body w e i g h t more than b r e e d .  difference  in  intake  indicated  that  in  between b r e e d s and  between b r e e d s  most  studies  of  beef  breed  steers  intake with  a  with mean  s t u d y p e r i o d , a l t h o u g h t h i s may  be  B l a x t e r et_ a l . (1961) a l s o n o t e d a of  sheep, however, Weston  voluntary  s t r a i n s more c a r e  p r e p a r a t i o n of the e x p e r i m e n t a l  an e f f e c t on  feed  i s required  animals.  intake  i n the  (1982)  differences  selection  Thus, the d a t a may  not  and  reliably  i n d i c a t e p o p u l a t i o n means. Differences differences Starting higher  in  i n intake the  initial  due  to  sex  weight  w e i g h t s when growing  cattle  f o r d a i r y than beef s t e e r s and  heifers.  and of  b r e e d may  cattle  (Owens  were a d m i t t e d  Another  factor  l e s s t h a n one  a f f e c t i n g intake  to  associated  was  with  et_ a l _ . , 1985). a  feedlot  beef s t e e r s were h i g h e r  They n o t e d t h a t f o r a g i v e n w e i g h t , f e e d  beef s t e e r s and h e i f e r s was  be  were  than beef  i n t a k e d i f f e r e n c e s by  percent. stage  of  pregnancy.  In  pregnancy, Campling (1966) found t h a t the pregnant monozygotic t w i n s  late ate  l e s s hay  than t h e i r non-pregnant  sisters.  d e c r e a s e i n f e e d consumption was by  physical  that  the  f a c t o r s but  reason  feed  Weston (1982) noted t h a t the  not c o n f i n e d t o d i e t s l i m i t e d i n i n t a k e  a l s o by m e t a b o l i c f a c t o r s .  intake  falls  was  not  He  established,  upward d i s p l a c e m e n t of the v e n t r a l rumen w a l l reduced may  be  a factor.  Constant  to  say  although  the  rumen volume, and  f e e d i n t a k e s have been r e c o r d e d w i t h a  d e c r e a s e i n rumen volume and factor.  goes on  i n c r e a s e d e s t r o g e n s e c r e t i o n may  I n many c a s e s , pregnancy  30%  a l s o be a  and l a c t a t i o n a r e confounded  making i t  d i f f i c u l t t o d i f f e r e n t i a t e between the two p h y s i o l o g i c a l s t a t e s . Campling intake  (1966) n o t e d  than pregnancy  that  w i t h the l a c t a t i n g  than the d r y , non-pregnant the  animal.  increase i n milk y i e l d .  (Dulphy e t a l . ,  l a c t a t i o n had dairy  a much g r e a t e r e f f e c t cow  e a t i n g 29% more hay  I n t a k e l a g g e d s e v e r a l weeks b e h i n d  Similar  results  have been noted  i n ewes  1980).  Weston (1982) s t a t e d t h a t no c l e a r q u a n t i t a t i v e r e l a t i o n s h i p between v o l u n t a r y consumption evidence that 1974).  noted  f a t ruminants  During l a c t a t i o n  tends t o be no  inversely  and body c o m p o s i t i o n even though eat l e s s  i n dairy  related  cows and  ewes, v o l u n t a r y f e e d  t o body f a t c o n t e n t .  F i n a l l y , B a i l e and Forbes  Other  lighter  Forbes, intake  s t u d i e s have  mature a n i m a l s .  (1974) i n d i c a t e t h a t e x e r c i s e can have a  s i g n i f i c a n t e f f e c t on i n t a k e w i t h g r a z i n g a n i m a l s r e q u i r i n g f o r maintenance  exists  t h e r e was  than t h i n ones ( B a i l e and  change i n I n t a k e between h e a v i e r and  more energy  on  than  stall  fed animals.  substantially  Animals  tend  to  compensate f o r i n c r e a s e d r e q u i r e m e n t s by e a t i n g more.  2.1.3  PLANT FACTORS AFFECTING INTAKE In  a d d i t i o n t o the many a n i m a l r e l a t e d  f a c t o r s t h a t have an  impact  on i n t a k e of f o r a g e s , intake. stage  These at  plant  date  of  genus, s p e c i e s harvest;  and  plant  part  variety; (leaf  affect  phenological  or  stem);  i n t a k e was  (1982) i n d i c a t e d  that  the  main  factors  the p r o p o r t i o n of u n d i g e s t i b l e r e s i d u e s  time  throughout  the  rumen and  the  controlling  animal  i n the f e e d s ,  s i z e of  the  residue  rumen.  Feeds  d i f f e r i n the t i m e r e q u i r e d f o r them t o be b r o k e n down t o p a r t i c l e s enough  and  composition.  Minson  transit  include  harvest;  chemical  t h e r e are a number of p l a n t f a c t o r s t h a t may  to  escape  degrees, are  from  the  i n f l u e n c e d by  rumen the  and  these  differences,  factors discussed  a l s o a f f e c t the r e l a t i o n s h i p between i n t a k e and  below.  to  small  varying  These f a c t o r s  digestibility  for various  feeds.  2.1.3.1 It  FORAGE TYPE, SPECIES AND has  been  recognized  VARIETY  for  some time  that  legumes  are  eaten  greater  q u a n t i t i e s than g r a s s e s of s i m i l a r energy d i g e s t i b i l i t y  1982).  Troelson  hay  was  Thornton  about and  and 10%  Campbell (1969) showed t h a t higher  Minson  (1973)  than  that  found  that  o r g a n i c m a t t e r from a legume d i e t was The  r e t e n t i o n time i n the rumen was  t o the h i g h e r the  i n t a k e of legume.  rumen w h i l e  the  voluntary  the  the  higher  grass  (Minson,  i n t a k e of species  mean v o l u n t a r y  alfalfa studied.  intake  of  than t h a t of the g r a s s d i e t .  p r o b a b l y a major f a c t o r c o n t r i b u t i n g  The  g r a s s e s were r e t a i n e d 17% l o n g e r i n  intake  higher  than  W a l t e r s (1971) found t h a t , a t the same l e v e l of d i g e s t i b i l i t y ,  there  g r a s s e s when d i g e s t i b i l i t y of b o t h was  were  of  the  in  differences  arundinacea  in  Schreb.),  intake  of  perennial  of  legumes was  282  60%.  orchardgrass, ryegrass  (  tall Lolium  fescue perenne  (  Festuca L.)  and  timothy.  Troelson  was l o w e r  and Campbell (1969) a l s o noted t h a t r e e d canary g r a s s  i n dry matter  intake  (DMI) t h a n  bromegrass o r R u s s i a n w i l d r y e g r a s s (DMD). for  Walters  either  crested  wheatgrass,  a t s i m i l a r dry matter d i g e s t i b i l i t i e s  (1971) showed t h a t , a t t h e mean l e v e l o f d i g e s t i b i l i t y  t h o s e g r a s s e s he examined, t h e g r a s s e s were a t d i f f e r e n t s t a g e s o f  growth  with  different  comparisons between  proportions  species  of  are often  anatomical d i f f e r e n c e s (Norton,  1982).  leaf  and  confounded  stem.  Meaningful  by m o r p h o l o g i c a l  and  D i g e s t i b i l i t y , rate of d i g e s t i o n ,  c h e m i c a l f a c t o r s , p h y s i c a l f a c t o r s and e x t e r n a l f a c t o r s such as mold may also  influence  al.,  1964). Seoane  greater  differences  et^ a l .  than  that  (1981)  o f Champ  i n i n t a k e between f o r a g e  found  the intake  and C l i m a x  timothy intake  v a r i e t i e s measured between  species.  s i g n i f i c a n t l y higher and for  Campbell  noted  the  (1971) a l s o  as t h a t  earlier  Differences i n  between d i f f e r e n t  heading  v a r i e t i e s had  i n t a k e s than t h e l a t e r h e a d i n g v a r i e t i e s .  (1969) r e p o r t e d  that  two v a r i e t i e s o f a l f a l f a  t o be  g r a s s , p e r e n n i a l r y e g r a s s and  n o t as wide  that  (Minson et^  timothy  Walters  a t t h e same d i g e s t i b i l i t y .  v a r i e t i e s was  I t was  o f Bounty  timothies.  found d i f f e r e n c e s i n i n t a k e between o r c h a r d  species  Troelson  e a r l y i n t h e season, DMI was s i m i l a r  while  differences at similar d i g e s t i b i l i t i e s .  later  i n t h e season  there  were  The a u t h o r s a t t r i b u t e d t h i s t o  variations i nleafiness. 2.1.3.2  PLANT MATURITY AND DATE OF CUTTING  Troelson was  reduced.  digestibility.  and Campbell (1969) found t h a t as t h e p l a n t matures, i n t a k e The  authors  indicated  W a l t e r s (1971) r e p o r t e d  this  was  related  to  decreasing  t h a t d i g e s t i b i l i t y accounted f o r  a major p o r t i o n o f t h e v a r i a b i l i t y o f i n t a k e i n f i r s t c u t f o r a g e .  Minson  et  a l . (1964)  digestibility  also  showed  a  general  fall  i n intake  as  herbage  d e c r e a s e d w i t h f i r s t h a r v e s t b e i n g done s u c c e s s f u l l y l a t e r  i n t h e growing season. When a f o r a g e season,  was h a r v e s t e d  t h e number  of  days  two o r more times  to harvest  n u t r i t i o n a l v a l u e ( W a l t e r s , 1971).  was  a  during  major  t h e growing  indication  of  T r o e l s o n and Campbell (1969) r e p o r t e d  that l e a f i n e s s d e c l i n e s w i t h advancing maturity reducing the a v a i l a b i l i t y of  crude p r o t e i n and s o l u b l e c a r b o h y d r a t e s .  The changing l e a f  t o stem  r a t i o may a l s o be a f a c t o r i n d e c r e a s i n g n u t r i t i v e v a l u e . Akin forage  (1982) p o i n t e d  out that  the t o t a l  i n c r e a s e s as t h e p l a n t matures.  cell  I n g r a s s e s , q u a l i t y was reduced  w i t h the t r a n s l o c a t i o n of s o l u b l e carbohydrates to  the inflorescence r e s u l t i n g  w a l l c o n s t i t u e n t s of  i n increased  from t h e stem and l e a v e s  l i g n i f i c a t i o n and d e c r e a s e d  l e a f t o stem r a t i o . The drop  drop i n i n t a k e was l e s s i n legumes than g r a s s e s due t o a s m a l l e r  i n quality  (Troelson  and C a m p b e l l ,  1971) even  though  intake of  a l f a l f a decreased w i t h i n c r e a s i n g m a t u r i t y i n c o n j u n c t i o n w i t h  decreasing  energy (Heaney, 1970). 2.1.3.3  CHEMICAL  COMPOSITION  As t h e p l a n t matures, an i n c r e a s e i n t h e f i b r e l e v e l u s u a l l y o c c u r s r e s u l t i n g i n a r e d u c t i o n i n p r o t e i n and n o n - s t r u c t u r a l c a r b o h y d r a t e s an a s s o c i a t e d r e d u c t i o n i n i n t a k e and d i g e s t i b i l i t y  ( M i n s o n , 1982).  c e l l w a l l c o n s t i t u e n t l e v e l s i n c r e a s e , i n t a k e d e c l i n e s (Van S o e s t , In forages w i t h a high more  to  the  As  1965).  f i b r e l e v e l i n t h e c e l l w a l l , i n t a k e was r e l a t e d  individual  constituents l i m i t  with  animal's  energy  requirement.  Cell  wall  i n t a k e when 55 t o 60% o f t h e c e l l d r y m a t t e r i s made  up o f f i b r e c o n s t i t u e n t s .  I n a g e n e r a l way, t h e n , as t h e f i b r e component  of a p l a n t i n c r e a s e s , i n t a k e d e c r e a s e s . Lignen  shows  the  poorest  r e l a t i o n s h i p w i t h i n t a k e (Van correlated f i b r e was  with not  f o r a g e and This  was  and  cell  S o e s t , 1965)  a l l fibrous plant  wall  constituents  even though l i g n i n was  components.  This  necessarily closely related with  the  does not n e c e s s a r i l y i n c r e a s e u n i f o r m l y the  case w i t h  the  a l f a l f a w h i c h has  was  best highly  because  total  l e v e l of l i g n i n i n a as the f o r a g e  a higher  lignin  g r a s s e s but i s g e n e r a l l y consumed i n g r e a t e r amounts.  matures.  content  In grasses,  than lignin  tends t o i n c r e a s e more or l e s s l i n e a r l y w h i l e c e l l w a l l c o n s t i t u e n t s tend t o i n c r e a s e r a p i d l y e a r l y i n the season and Meijs  was  no  r e l a t i o n s h i p between crude p r o t e i n or crude f a t c o n t e n t of the feed  and  feed i n t a k e by  the  feed  (1981)  falls  the cows.  below 6-8%,  circulating  amino a c i d s  t h a t p r o t e i n was a  biological  forages  with  i n t a k e or  that  in  dairy  less  there  However, when the crude p r o t e i n c o n t e n t of intake  drops, apparently  ( B a i l e and  since than  the  6%  due  F o r b e s , 1974).  s u p p l e m e n t a t i o n of  crude  protein  did  to a d e f i c i e n c y Lipke  (1980) found  additional protein  not  of  c o u l d not e s t a b l i s h  appreciably  (1982) i n d i c a t e d t h a t a number of r e g r e s s i o n and,  to  increase  to account f o r a l l of  the  differences  caused by  i n i n t a k e between samples.  t r u e d i f f e r e n c e s i n i n t a k e of  s p e c i e s of the same c h e m i c a l c o m p o s i t i o n . and  e q u a t i o n s have  a l t h o u g h they a r e s i g n i f i c a n t , c h e m i c a l c o m p o s i t i o n  Most of the v a r i a t i o n was  1965) .  rations  s i g n i f i c a n t l y r e l a t e d to i n t a k e but  basis  been f o r m u l a t e d  intake  cow  digestibility.  Minson  fails  indicated  then l e v e l o f f .  The  i n t e r r e l a t i o n s h i p s between  c h e m i c a l c o m p o s i t i o n are h i g h l y s p e c i e s - o r i e n t e d In  addition,  differences  in  intake  plant  between  f r a c t i o n s o c c u r w i t h the i n t a k e of l e a f c o n s i d e r a b l y  (Van  leaf  higher  and  Soest, stem  than stems of  s i m i l a r chemical Van  Soest  composition.  (1965) i n d i c a t e d t h a t c h e m i c a l c o m p o s i t i o n was  more c l o s e l y r e l a t e d t o d i g e s t i b i l i t y of  cell  wall  constituents  e s p e c i a l l y w i t h i n species  2.1.3.4  LEAF AND  (fibrous  always  than  although  i n 30  difference  of  1982).  T h i s may  more f e e d Minson  t o be  (1982)  1%  be  the  greater  the  The  digestibility,  the  42%  stem than  the  same  between d i f f e r e n t s p e c i e s  of  the  two  fractions  the  and stem  M i n s o n , 1973;  larger  a  (Minson,  retained for a  rumen than the stem p o r t i o n w h i c h  that due  at  l o w e r f o r stems than l e a v e s w i t h  consumed (Laredo and  masticated  fraction  r e s u l t of the l e a f p o r t i o n b e i n g  of time i n the  suggested  stem  i n t a k e of l e a f  d i f f e r e n c e i n i n t a k e between l e a f and  in digestibility  f r a c t i o n i n the rumen was in  of  t h a t the v o l u n t a r y  levels varied  comparisons was  only  shorter period  that  the  the m a t u r i t y of r e g r o w t h . fractions  with  STEM  higher  digestibility  material)  t o the c o r r e l a t i o n  (Osbourn, 1978).  Laredo and M i n s o n (1973) r e p o r t e d was  t h a n i n t a k e due  generally  allowed  P o p p i e t a l . , 1980).  retention  time  of  the  stem  t o the h i g h e r p r o p o r t i o n of l a r g e p a r t i c l e s i n masticated  r e s i s t a n c e t o p h y s i c a l breakdown.  l e a f because the  stem shows  These l a r g e p a r t i c l e s of  the  stem w i l l remain l o n g e r i n the rumen than the l a r g e p a r t i c l e s of the l e a f fraction.  2.1.3.5 The  CHOPPING AND  PELLETING  i n t a k e of a f o r a g e was  pelleted i n t a k e was  as  compared  to  long  u s u a l l y i n c r e a s e d when i t was hay  (Minson,  1982).  The  ground  and  difference  in  a s s o c i a t e d w i t h a f a s t e r r a t e of passage t h r o u g h the rumen but  chopping per particle  se would not  size  Weston  (between 4 and  consumption was straw  41%  that  p e l l e t i n g was composition  and  the  8 mm)  (1967)  higher  consumption was  concluded  2.2  Hogan  i n c r e a s e i n t a k e o v e r l o n g hay  31% h i g h e r  chopped  (Robles  that  alfalfa  et a l . , 1980).  ground hay  alfalfa  and  ground  than chopped wheat s t r a w .  voluntary  not accompanied by any  o f the  reached  indicated  than  increased  was  until a certain  intake  caused  The  by  hay wheat  authors  grinding  s i g n i f i c a n t changes i n the  and  chemical  diet.  FACTORS AFFECTING FEED DIGESTIBILITY Schneider  and  Flatt  of the f e e d o r of any  (1975) d e f i n e d i g e s t i b i l i t y  "as  the  s i n g l e n u t r i e n t of the f e e d w h i c h was  percentage  d i s s o l v e d or  otherwise  a c t e d upon i n the e n t i r e d i g e s t i v e t r a c t so i t can be  and  put  thus  animal  at  the  d i s p o s a l of  the  body  cells".  absorbed  There a r e  and p l a n t r e l a t e d f a c t o r s t h a t a f f e c t d i g e s t i b i l i t y  several  of f e e d s t u f f s  which are d i s c u s s e d i n t h i s s e c t i o n . 2.2.1  ANIMAL FACTORS AFFECTING DIGESTIBILITY Blaxter  and  Wainman  (1961) r e p o r t e d  w h i c h consumed the most f e e d al.,  (1967) o b t a i n e d  digested  that, i n cattle,  i t least  the  efficiently.  animals  U l y a t t et  r e s u l t s t h a t showed a s i g n i f i c a n t d e c r e a s e i n f e e d  d i g e s t i b i l i t y i n the rumen but a s i g n i f i c a n t i n c r e a s e i n d i g e s t i b i l i t y i n the  lower  alimentary  suggest t h a t w i t h reducing although Van  increased  retention t h e r e was Soest  digestibility  by  tract,  time  in  as  feed  feed the  i n t a k e was  i n t a k e , the rumen  and  increased.  The  r a t e of passage therefore  authors increased  digestibility,  a compensatory e f f e c t d i s t a l to the rumen.  (1982)  summarized  the  r e l a t i o n s h i p between  i n d i c a t i n g that d i g e s t i b i l i t y  d e p r e s s i o n was  intake  and  a function  of  the  competition  slowest  digesting  hemicellulose passage of  —  an  between  fractions  are  the  of  the  the  cell  most a f f e c t e d .  average f o r a g e  r e t a i n e d f o r 40  t o 60 h o u r s .  retention  time  to  concluded  that  about  30  rate wall  of —  passage.  The  cellulose  and  Measurements of  i n d i c a t e that  cell  the  rate  wall constituents  depression  digestibility  between  feed  are  30  intake  of are  D o u b l i n g the f e e d i n t a k e w i l l d e c r e a s e the to  33  hours  in  sheep.  Van  Soest  t h o s e c e l l w a l l c o n s t i t u e n t s s u s c e p t i b l e t o the  digestibility  increased  d i g e s t i o n and  those that  and  48  results  hours in  (1982) greatest  show a s u b s t a n t i a l i n c r e a s e of  reduced  fermentation. feed  As  a  in  result,  digestibility  in  most  cases. 2.2.2  PLANT FACTORS AFFECTING DIGESTIBILITY Several  species stem;  and  plant  v a r i e t y ; maturity  chopping  2.2.2.1  factors affect d i g e s t i b i l i t y  and  and  pelleting;  and  FORAGE TYPE, SPECIES AND  Even though DMI  was  c u t t i n g date; the  higher,  DMD  season ( T r o e l s o n and C a m p b e l l , 1969;  of  l o w e r DMD  factors.  Legumes tend  that  cellulose  of  chemical  leaf  and  treatments.  of  legumes was  g e n e r a l l y lower  or  at s i m i l a r p e r i o d s of the growing  T h o r n t o n and M i n s o n , 1973).  t o have a h i g h e r  was  due  c e l l w a l l content  (Osbourne et_ a l . , 1974).  t o a number (and  less  Even though  the c a s e , the p r o p o r t i o n of d i g e s t e d c e l l w a l l m a t e r i a l i s about  the same ( M o i r , 1972). found  of  of legumes compared w i t h g r a s s e s  c e l l s o l u b l e m a t e r i a l ) than g r a s s e s t h i s was  proportion  type,  VARIETY  o n l y e q u a l t o t h a t of g r a s s e s h a r v e s t e d  The  efects  i n c l u d i n g forage  Mosley and  c l o v e r had and  proportionately  higher less  lower l e v e l N of  Jones (1984) and of  l e v e l s than the  Beever e t a l . (1985)  soluble carbohydrates, grasses  ingested  and  organic  that matter  comparable  i n clover appeared  diets, to  be  digested were  i n the  retained  percentage  rumen. for  of  a  white  Thornton  and  Minson  shorter  period  clover  particulate  d i s a p p e a r i n g i n the f i r s t  3 hours  in  (1973) found  the  rumen  matter  t h a t legumes  with  than  a f t e r consumption  a  greater  of  (Moseley  ryegrass and  Jones,  1984). Both M i n s o n £t  a l . (1964) and  T r o e l s o n and  Campbell  (1969)  d i f f e r e n c e s i n d i g e s t i b i l i t y between g r a s s s p e c i e s depending of  on t h e s t a g e  growth w i t h the second a u t h o r s r e p o r t i n g i n c r e a s e d v a r i a b i l i t y  as growth valid  progresses.  The  first  t o compare the d i f f e r e n t  authors concluded  i t was  found  not  in  DMD  generally  s p e c i e s a t d e f i n e d s t a g e s of growth  r a t h e r t h a t d a t a must be i n t e r p r e t e d i n c o n j u n c t i o n w i t h y i e l d  and  but  season  of p r o d u c t i o n . Digestibility than  the  digestibilities  Milford digestible soluble  and than  (1985)  digestibility digested  ryegrass  l e v e l s would found  the  that  first  (1966) at  content  found  of  the  orchardgrass  was  less  reflecting  the  lower  stages  increased f i b r e  the  et^ a l _ . , 1964) .  orchardgrass.  higher  g r a s s e s showed lower d i g e s t i o n  Differences similar  (Minson  that  a l l growth  indicate in  growths  much l e s s v a r i a b l e  Lower  levels  quality  and  i n DMD  growth  coefficients  soluble Burns e t  forages  o f o t h e r f i b r e c o n s t i t u e n t s were a l s o h i g h e r .  c e l l u l o s e and c e l l w a l l  at  of  Minson  carbohydrate  carbohydrate al.  of the r e g r o w t h of any s p e c i e s was  studied, The  poorly  for hemicellulose,  constituents. between v a r i e t i e s have been r e p o r t e d i n g r a s s e s  stages  or percentage  of  leaf  ( W a l t e r s , 1971).  In  a n o t h e r study the v a r i e t y i n a n o t h e r study w i t h the h i g h e s t d i g e s t i b i l i t y also  had  variety  the  highest  w i t h the  lower  p r o p o r t i o n of digestibility  soluble had  the  carbohydrates lowest  levels  while of  the  soluble  c a r b o h y d r a t e s ( B l a n d and Dent, 2.2.2.2 It  1964).  PLANT MATURITY AND DATE OF CUTTING was g e n e r a l l y  a c c e p t e d t h a t DMD  d e c l i n e s w i t h advancing  forage  growth t h r o u g h t h e growing season ( T r o e l s o n and C a m p b e l l , 1969; White and Wight, 1981). For  However, t h e r e can be some e x c e p t i o n s t o t h e g e n e r a l c a s e .  example,  Hidiroglou  e t a l . (1966)  reported that  t i m o t h y showed no  apparent d e c l i n e i n d i g e s t i b i l i t y from mid-August t h r o u g h mid-October and T r o e l s o n and Campbell did  not d e c l i n e  (1969) i n d i c a t e d t h a t l a t e r i n t h e season  i n nutritional  value.  Cutting  e f f e c t s a r e n o t always p r e d i c t a b l e because of growth 1982).  r e t a r d s growth b u t t h e  f a c t o r s other than the stage  ( s u c h as e n v i r o n m e n t a l e f f e c t s ) must be c o n s i d e r e d (Van S o e s t ,  However, b o t h H i d i r o g l o u e t a l . (1966) and Minson e t a l . (1964)  i n d i c a t e d t h a t r e g r o w t h i n g r a s s e s was l e s s d i g e s t i b l e t h a n f i r s t Wilman portion  alfalfas  and A t l i m i m i  of the plant  (1982)  declined  f a s t e r than t h e l e a f b l a d e .  indicated  that  in digestibility  growth.  i n r y e g r a s s , t h e stem w i t h advancing m a t u r i t y  The d i g e s t i b l e energy c o n t e n t i n t h e stems  d e c l i n e d a t more t h a n t w i c e t h e r a t e o f t h e d e c l i n e i n t h e l e a v e s (Hacker and  Minson,  1981).  In addition,  dry matter,  crude  protein,  sugars and c e l l u l o s e were more d i g e s t i b l e i n a l f a l f a l e a v e s than  soluble alfalfa  stems w h i l e crude f i b r e was more d i g e s t i b l e i n t h e stems. Reasons f o r t h e d e c l i n e i n DMD have been suggested by T r o e l s o n and Campbell  (1969)  and K i l c h e r  and T r o e l s o n (1973).  Crude p r o t e i n  levels  d e c l i n e d w i t h a d v a n c i n g m a t u r i t y i n b o t h t h e l e a v e s and stems o f a l f a l f a and  bromegrass  stems.  w h i l e crude  fibre  levels  increased  i n both  l e a v e s and  C e l l w a l l l i g n i n i n c r e a s e d a t a s l o w e r r a t e i n t h e l e a v e s than i n  t h e stems as t h e p l a n t s matured. digestibility  The d e p r e s s i n g e f f e c t o f crude f i b r e on  was due t o t h e p r e s e n c e o f l i g n i n w h i c h p r o t e c t s some o f  t h e c e l l u l o s e and h e m i c e l l u l o s e o f t h e c e l l w a l l from m i c r o b i a l d i g e s t i o n (Hacker and M i n s o n , 2.2.2.3  1981).  LEAF AND STEM  Van Soest (1982) s t a t e d t h a t , i n g e n e r a l , stems a r e u s u a l l y o f lower quality  than  leaves.  In Italian  and p e r e n n i a l  ryegrass harvested at  s i m i l a r s t a g e s o f m a t u r i t y , t h e l e a f component o f t h e p l a n t had a h i g h e r DMD  than  the  digestibility 2.2.2.4  stem  component,  was  consistent  with  a  higher  of t h e c e l l w a l l c o n s t i t u e n t s (Wilman and A l t i m i m i ,  1982).  CHOPPING AND PELLETING  It  was  generally  recognized  reduced when f e e d s a r e ground Van  which  S o e s t , 1982).  that  dry matter  and p e l l e t e d  digestibility  (Greenhalgh  and R e i d , 1973;  The response d i f f e r s between f o r a g e s p e c i e s , i n p a r t  due t o t h e g r e a t e r d e p r e s s i o n o f o r g a n i c m a t t e r d i g e s t i b i l i t y milling  i n d u c e d by  t h e g r a s s e s compared w i t h t h e legumes (Osbourne e t al^. ,  Weston  was  and Hogan  (1967)  indicated  that  a t ad_ l i b i t u m  1981).  levels  of  f e e d i n g t h e r a t e o f f l o w from t h e abomasum was 20-301 h i g h e r w i t h ground hay than w i t h chopped hay. and  alfalfa  would  R o b l e s e t a l . (1980) found t h a t o r c h a r d g r a s s  have t o be ground  before a reduction i n d i g e s t i b i l i t y particles  are longer  digestibility maximum  passage  of  materials o f food  digestibility  8 mm  Blaxter  wall  structural  s c r e e n s s m a l l e r than 8 mm  be e x p e c t e d . would  Chopped f o r a g e s  not e x h i b i t  and Graham  (1956)  found  of f i n e l y  ground  grass  constituents.  T h i s was expected  carbohydrates  have a lower through  would  and thus  i n digestibility  i n the c e l l  fermentation ground  depression.  depression  occurred  than  through  retention  the d i g e s t i v e  was time  tract  slow  t h e same that the material since the  and, s i n c e  finely  i n t h e rumen, t h e r a p i d would  result  o f t h e f i b r o u s components o f t h e c e l l w a l l .  i n reduced  The e f f e c t o f  pelleting  mature  forages  lignified  c e l l w a l l s c o l l a p s e l e s s on p e l l e t i n g  younger f o r a g e s and  the  on  digestibility  intake  may  of d i g e s t i b l e  be  limited  because  than the l e s s  n u t r i e n t s may  the  lignified remain  low  (Van S o e s t , 1982). 2.2.2.5  CHEMICAL TREATMENTS  C h e m i c a l t r e a t m e n t s ( u r e a , ammonia o r NaOH) s i g n i f i c a n t l y i n c r e a s e d the d i g e s t i b i l i t y of poor q u a l i t y f e e d s (Wanapet est a l . , 1985) . (1984) a l s o r e p o r t s t h a t the i n t a k e of s t r a w was w i t h ammonia. to  Crude f i b r e d i g e s t i b i l i t y was  20 p e r c e n t a g e u n i t s ) due,  hemicellulose  increasing  hemicellulose digestion. and  anhydrous  rate  and  i n c r e a s e d when t r e a t e d  s u b s t a n t i a l l y i n c r e a s e d (10  the a u t h o r s f e e l ,  the  Sundstol  t o the s o l u b i l i z a t i o n of  extent  of  cellulose  and  N b a l a n c e s were improved by t r e a t m e n t w i t h u r e a  ammonia but  NaOH  treatment  resulted  i n higher  overall  digestibilities. 2.3  ENVIRONMENTAL FACTORS AFFECTING INTAKE AND Van  which  Soest  et  a l . (1978) r e p o r t e d t h a t  increases l i g n i n ,  digestibility  was  DIGESTIBILITY environmental  temperature,  the dominant e n v i r o n m e n t a l f a c t o r  effecting  w h i l e the o t h e r e f f e c t s ( t e m p e r a t u r e , w a t e r , f r o s t ,  light,  season and d a y l e n g t h ) a r e secondary. The e f f e c t s of temperature on DMD  i n d i c a t e t h a t the d i g e s t i b i l i t y  of  temperate f o r a g e s grown i n warm a r e a s can be a f f e c t e d i n a manner s i m i l a r to DMD  tropical and  1968). aging  f o r a g e s and  i n c r e a s e d temperatures  can r e s u l t  i n c r e a s e d p r o p o r t i o n s of c e l l w a l l c o n s t i t u e n t s H i g h temperatures  and  appear  apparently decrease  i n decreased  (Deinum et_ a l . ,  t o h a s t e n the normal p r o c e s s o f t i s s u e  the d i g e s t i b i l i t y  of e x i s t i n g  cell  wall  m a t e r i a l ( W i l s o n et_ a l . , 1976) . W i l s o n and  Ng  (1975) c o n c l u d e d  t h a t water  stress  c l e a r l y retarded  p l a n t development w i t h s t r e s s e d l e a v e s b e i n g t h e i r a c t u a l age. at  o n t o g e n e t i c a l l y younger than  a comparison o f w a t e r s t r e s s e d and u n s t r e s s e d  t h e same p h y s i o l o g i c a l age r e v e a l s v i r t u a l l y  the  content of c e l l  Generally,  wall material  any f a c t o r t h a t  or nitrogen  retards  plant  leaves  no e f f e c t of s t r e s s on i n s p e c i f i c plant  development tends t o  parts. maintain  q u a l i t y and t h u s w a t e r s t r e s s r e s u l t s i n a more d i g e s t i b l e crop o f l o w e r y i e l d (Van S o e s t , e t a l . , 1978). Frost with  r e s u l t s i n a r a p i d d e c l i n e i n the n u t r i t i v e value  frost k i l l e d  leaves  more thawing p a t t e r n s digestible plant  d e c l i n i n g r a p i d l y i n DMD  and CP.  of grasses  F r e e z i n g and  l e a d t o l e a c h i n g and r e s p i r a t i o n l o s s e s o f t h e more  constituents  (Wilson,  1982) by d e g r a d i n g t h e components  of t h e t r a n s l o c a t i o n p a t h system and u l t i m a t e l y a f f e c t i n g o t h e r processes i n c l u d i n g photosynthesis Increased levels  of  light grasses  carbohydrates  (Right  ( B u l a and M a s s e n g a l e , 1972).  i n t e n s i t y increased through  the  e t a l _ . , 1968) .  soluble  carbohydrate  photosynthetic Light  Thus f o r a g e s  and  accumulation  induced photosynthesis  promoted t h e r e d u c t i o n o f n i t r a t e and i t s c o n v e r s i o n , w i t h t o amino a c i d s and p r o t e i n .  metabolic  DMD of also  carbohydrates,  grown under cloudy  conditions  o r i n humid, foggy a r e a s under reduced l i g h t c o n d i t i o n s w i l l be lower i n DMD t h a n f o r a g e s The studies  DMD  from a r i d environments (Van Soest e t a l . , 1978).  of grasses  higher  i n the spring  (White and W i g h t , 1981; R e i d e t a l . , 1967).  e t a l . (1966) o b t a i n e d Ontario.  was  The  first  h i g h e r DMD result  i n f a l l harvested  was  associated  with  than  1967) w h i l e  f o r two  However, H i d i r o g l o u forage  from  higher  c o n s t i t u e n t s and l o w e r s o l u b l e c a r b o h y d r a t e s i n t h e f a l l al.,  fall  northern  cell  forage  wall  (Reid e t  i n t h e second c a s e , crude f i b r e l e v e l s were lower and  crude p r o t e i n l e v e l s h i g h e r  i n t h e f a l l than i n t h e s p r i n g ( H i d i r o g l o u e t  a l . , 1966).  Deinum et^ a l .  (1968) i n d i c a t e d t h a t v e g e t a t i v e g r a s s i n h i g h  summer time w i l l have a s l i g h t l y h i g h e r DMD light part  intensity  and  still  of the season.  varies  due  to  relationship daylength  a  being  c o m p a r a t i v e l y h i g h temperatures  Thus, the e f f e c t of season  number  with a  t h a n i n autumn due to the  of  factors  temperature  and  principle  factor  (Van  and  Soest  daylength  et  varies  influencing  i n the  low  later  d a y l e n g t h upon  DMD  a l . , 1978) .  The  with  the  the  amount  season, of  light  received.  2.4  TROPICAL VERSUS TEMPERATE FORAGES The  temperate This all  v o l u n t a r y i n t a k e of t r o p i c a l g r a s s e s was grasses  harvested  at  the  same growth  i s associated with higher f i b r e  levels  stage  l e s s than f o r  (Minson,  1981).  i n the t r o p i c a l g r a s s e s a t  s t a g e s of growth r e s u l t i n g i n lower dry m a t t e r d i g e s t i b i l i t y ,  q u a n t i t i e s of i n d i g e s t i b l e f i b r e and However, t r o p i c a l  grasses  grass  at  60%  are u s u a l l y  digestibility  temperate g r a s s would be mesophyll  intercellular  cells  was  young  stemmy and  in tropical  a i r spaces  lower  larger  l o n g e r r e t e n t i o n time i n the rumen. consumed i n g r e a t e r amounts  temperate g r a s s e s of the same d i g e s t i b i l i t y .  that  usually  T h i s was because a t r o p i c a l  and  relatively  mature.  grasses  than  Norton  are  leafy  while  (1982) p o i n t e d  more d e n s e l y  packed  i n volume t h a n temperate g r a s s e s .  a out and  This  r e s t r i c t s t h e e n t r y of m i c r o b i a l d i g e s t i v e enzymes t h e r e b y d e p r e s s i n g the r a t e of d i g e s t i o n o f the f i b r o u s t i s s u e s of t h e p l a n t .  T h i s would r e s u l t  i n l o n g e r r e t e n t i o n time and t h e r e f o r e lower i n t a k e of t r o p i c a l g r a s s e s . The temperate indicate  DMD  of  grasses that  tropical and  tropical  grasses  legumes. forages  was  generally  Summaries  of  lower  reported  have d i g e s t i b i l i t i e s  of  than  that  of  digestibilities about  15  units  lower  than  temperate  digestibility grown  forages  and t r o p i c a l  conditions  and McLeod,  1970).  The lower  appears t o be due t o h i g h e r t e m p e r a t u r e s a t w h i c h they a r e  and n o t due t o b a s i c  Temperate  (Minson  differences  grasses  grown  had s i m i l a r d r y m a t t e r  between them  under  t h e same  digestibilities  (Minson,  temperature and  (Minson  and McLeod,  1970) and t h e a u t h o r s c o n c l u d e d t h a t d i f f e r e n c e s i n d i g e s t i b i l i t y two  categories  of forages are c l o s e l y associated  with  1981).  of the  differences i n  climate. 2.5  LABORATORY METHODS OF ASSESSING FORAGE VALUE In  vivo  techniques f o r estimating  e x p e n s i v e , t i m e consuming and r e q u i r e and C o l l i n s , 1982). faster  than  nutritional  animal  nutritive  v a l u e and i n t a k e a r e  l a r g e amounts o f f o r a g e ( F e r r e i r a  L a b o r a t o r y a n a l y s i s was g e n e r a l l y l e s s e x p e n s i v e and feeding  studies  and was  useful  i n explaining  phonomena and f o r d e s c r i b i n g f e e d c h a r a c t e r i s t i c s u s e f u l i n  f o r m u l a t i n g r a t i o n s (Van S o e s t , 1982). The major '  l a b o r a t o r y t e c h n i q u e s used f o r e v a l u a t i n g herbage q u a l i t y  i n c l u d e i n v i t r o dry matter d i g e s t i b i l i t y and jLn s i t u  ( N y l o n bag d r y m a t t e r  (IVDMD), c h e m i c a l ( e g . f i b r e ) ,  disappearance —  NBDMD) t e c h n i q u e s .  The i n v i v o parameters most o f t e n o f i n t e r e s t i n c l u d e d i g e s t i b l e energy (DE), and  dry matter d i g e s t i b i l i t y  voluntary  intake  (DMD), o r g a n i c m a t t e r d i g e s t i b i l i t y (OMD)  of dry matter  (DMI).  The p a r t i c u l a r  t e c h n i q u e used depends on t h e i n v i v o parameter be based  upon  experimentally  animal.  This  section,  determined  then w i l l  review  laboratory  t o be e s t i m a t e d and must  relationships with t h e commonly  the i n t a c t  used  laboratory  methods and how they r e l a t e t o a n i m a l p r o d u c t i v i t y . 2.5.1  PROXIMATE ANALYSIS The  Proximate A n a l y s i s  system  was t h e o l d e s t  method  of assessing  f o r a g e v a l u e and most work has t r a d i t i o n a l l y been done u s i n g t h i s system. Fonnesbeck represent  (1976) p o i n t e d  the feed  from one f e e d  f r a c t i o n s they were i n t e n d e d  was n o t n e c e s s a r i l y comparable  f r a c t i o n i n another feed pointed  out t h a t t h e p r o x i m a t e components do n o t  out t h a t  often  t o and crude f i b r e (CF) i n composition  ( F e r r e i r a and C o l l i n s , 1982). the l e a s t d i g e s t i b l e parts  l i g n i n , a r e e x t r a c t e d and i n c l u d e d i n t h e NFE. hemicellulose contain higher  was d i s s o l v e d .  the n o n - d i g e s t i b l e i n digestibility  As a r e s u l t ,  t h e NFE  this  Van Soest (1965)  o f f i b r e , x y l a n and  I n a d d i t i o n , most o f t h e  CF, w h i c h was b e l i e v e d t o  p o r t i o n of the feed,  than  with  was o f t e n e q u a l  ( F e r r e i r a and C o l l i n s ,  to or 1982).  Crampton and Maynard (1938) l o n g ago c o n c l u d e d t h a t t h e s p e c i f i c obtained is  from p r o x i m a t e a n a l y s i s have o f t e n been o v e r - e s t i m a t e d  e s p e c i a l l y t h e case f o r t h e f i b r e  fraction.  values  and t h i s  They f u r t h e r i n d i c a t e d  t h a t any r e l a t i o n CF may have t o t h e d i g e s t i b i l i t y of a f e e d may b e , i n part, fortuitous. In organic the  a  recent  evaluation  matter d i g e s t i b i l i t y  regression  coefficient  of laboratory  methods  f o r p r e d i c t i n g the  o f f o r a g e s , A e r t s _e_t a l . (1977) determined  o f CF f o r e s t i m a t i n g  in  v i v o OMD  of various  2 forages. OMD were  The r e s u l t s showed CF had an r  i n grass only  o f 0.35 f o r e s t i m a t i n g i n v i v o  hay, 0.68 f o r s i l a g e s and 0.59 f o r p e l l e t s .  slightly  lower  t h a n ADF  f o r grass  hays  (0.68) and about t h e same f o r s i l a g e s ( 0 . 6 5 ) . the  use o f CF t o e s t i m a t e  chemical  composition  of  the n u t r i t i v e the  residue  (0.41) and p e l l e t s  The main c r i t i c i s m  value  when  These l e v e l s  of a feed  compared  to  with  i s variable those  fibre  components a c t u a l l y d i g e s t e d by t h e a n i m a l . Similar  concerns  a r e expressed  about  crude  protein  (CP)  since  forages  also  non-protein lignin  contain nitrogen  varying  levels  and i n s o l u b l e  of n u c l e i c  nitrogen  acids,  found  water  soluble  i n association  with  (Van S o e s t , 1967).  Schneider  and F l a t t  (1975)  also  indicated  that  the ash f r a c t i o n  g i v e s no i n d i c a t i o n o f t h e a c t u a l m i n e r a l c o n t e n t o f t h e f e e d , n o r does the  proximate a n a l y s i s  system  evaluate vitamin  levels.  Both  types of  n u t r i e n t s a r e a concern because an i n a d e q u a t e s u p p l y o f even an e s s e n t i a l m i n e r a l o r v i t a m i n may r e s u l t i n p r o d u c t i o n problems. The  proximate  conservative  analysis  tendency  system  has c o n t i n u e d  to continue  d e s p i t e obvious l i m i t a t i o n s  to rely  i n u s e due  on e s t a b l i s h e d  to a  procedures  and i n a d e q u a t e u n d e r s t a n d i n g o f t h e meaning  and purpose o f f i b r e d e t e r m i n a t i o n s (Van S o e s t , 1967).  2.5.2  IN VITRO DRY MATTER DISAPPEARANCE While  there  techniques,  most  a r e many  i n vitro  are modifications  t e c h n i q u e (Rode and S a t t e r , 1984). while  i n vivo  nutritive  value  digestibility f o r ruminants  of  such  disappearance  the T i l l e y  Tilley  and T e r r y  (IVDMD) (1963)  and T e r r y (1963) e x p l a i n t h a t  experiments  r e q u i r e l a r g e amounts o f f e e d . digestibility  dry matter  a i d i n estimating  experiments  a r e time  forage  consuming  The c o r r e l a t i o n s between i n v i v o  and  herbage  and t h e c o n t e n t s o f i n d i v i d u a l c h e m i c a l components such as  CF, CP and l i g n i n a r e l i m i t e d and cannot be a p p l i e d e q u a l l y t o a l l f o r a g e plants. not  As a r e s u l t , i n v i v o d i g e s t i b i l i t y  available  to plant  breeders  and c h e m i c a l t e c h n i q u e s a r e  f o r such  purposes  as  the  initial  s e l e c t i o n o f new v a r i e t i e s . Ferreira generally  and C o l l i n s  been  reported  (1982)  c o n c l u d e d t h a t t h e IVDMD t e c h n i q u e has  superior  to  other  laboratory  methods f o r  p r e d i c t i n g i n v i v o DMD.  The t e c h n i q u e has been misused due t o a t t e m p t s  t o e s t i m a t e DMI from IVDMD v a l u e s , something for.  The  technique  was  most  useful  t h e p r o c e s s was n o t d e s i g n e d  f o r determining  the  relative  d i f f e r e n c e s between f o r a g e samples r a t h e r than as a means o f e s t i m a t i n g i n v i v o d i g e s t i b i l i t y due t o t h e numerous f a c t o r s a f f e c t i n g ( F e r r e i r a and C o l l i n s , Van  Soest  digestibility  1982).  (1982) has suggested  t h a t t h e main d i s a d v a n t a g e w i t h t h e  IVDMD t e c h n i q u e was t h e l e n g t h o f time and number o f s t e p s r e q u i r e d t o c a r r y out the procedure. innoculum.  The donor  A n o t h e r major d i s a d v a n t a g e was t h e v a r i a t i o n i n a n i m a l , method  of sampling  and p r o c e s s i n g t h e  innoculum, and t h e amount o f innoculum a l l a f f e c t t h e r e s u l t .  Variation  between a n i m a l s p e c i e s , i n d i v i d u a l s , o r t h e same a n i m a l between days have a l s o been n o t e d ( B a r n e s , 1973). 2.5.3  NYLON BAG DRY MATTER DISAPPEARANCE The  nylon  referred  t o as t h e i n s i t u  measuring effects  bag d r y m a t t e r  the r a t e  (Barnes,  o r i n sacco  and p o t e n t i a l  of various r a t i o n  parameters  disappearance  (NBDMD)  technique)  technique  (also  was u s e f u l f o r  e x t e n t o f d i g e s t i o n o f f e e d s and t h e  t r e a t m e n t s such as s u p p l e m e n t a t i o n , on these  1973).  The  technique  i n e x p e n s i v e method o f a s s e s s i n g f o r a g e q u a l i t y  provides  a  simple  and  ( P l a y n e et_ a _ l . , 1978) and  has been used t o examine t h e d i s a p p e a r a n c e o f DM, f i b r e and CP (Rode and Satter,  1984).  The main advantages  o f t h e t e c h n i q u e was p l a c i n g t h e  f e e d s t u f f i n t h e a c t u a l a n i m a l as opposed t o s i m u l a t i n g r u m i n a l a c t i v i t y in vitro. I n a comparison o f s e v e r a l d i f f e r e n t methods o f e s t i m a t i n g OMD A e r t s et a l . ,  (1977) found t h a t t h e NBDMD t e c h n i q u e (48 hours i n s i t u f o l l o w e d 2 by a 48 hour p e p s i n i n c u b a t i o n ) r e s u l t e d i n an r o f 0.92. T h i s was t h e  h i g h e s t r e l a t i o n s h i p o f any and  of the o t h e r t e c h n i q u e s ,  c h e m i c a l p a r a m e t e r s , examined.  i n c l u d i n g the IVDMD  However, Barnes (1973) r e p o r t e d  the t e c h n i q u e  was  s u b j e c t t o c o n s i d e r a b l e v a r i a t i o n and was  standardize.  Sources of v a r i a t i o n i n c l u d e s i z e and  type  difficult  of  the  suspension cleaning  host  in and  animal,  the  rumen,  rinsing  individuality l o c a t i o n and  incubated  bags,  of  time and  host  animal,  i n the  inclusion  to  of bags, c l o t h  mesh s i z e , sample s i z e , f i n e n e s s of g r i n d , number of samples per diet  that  trial,  method  of  rumen, methods  of  or  e x c l u s i o n of  a  second s t a g e p e p s i n d i g e s t i o n s t e p . Several  authors  subsequent DM  have examined  disappearance.  The  the  i m p o r t a n c e of  bag  pore  size  t h r e e main c o n s i d e r a t i o n s a r e  on  leaching  of undegraded m a t e r i a l s from the bags, e x c l u s i o n of rumen b a c t e r i a from the s u b s t r a t e w i t h i n the bag and a c c u m u l a t i o n in  the bag  (Van H e l l e n and E l l i s ,  1977;  e t a l . (1978) i n d i c a t e d t h a t DM  o f exogenous m a t e r i a l w i t h -  Mehrez and Orskov, 1977).  l o s s e s due  to l e a c h i n g c o u l d be  Playne serious  and a c o r r e c t i o n f a c t o r s h o u l d be used t o account f o r such l o s s e s . P l a y n e e t a l . (1978) i n d i c a t e d t h a t sample s i z e had DMD  as l o n g as sample s i z e to bag  s i z e r a t i o was  l i t t l e effect  on  h e l d c o n s t a n t ; however,  Nocek (1985) found t h a t c l u m p i n g of the s u b s t r a t e i n the bag  increased  as  sample w e i g h t i n c r e a s e d . Fineness from  the  (Playne  of the g r i n d of the s u b s t r a t e a l s o a f f e c t s DMD  bag et  being al.  n o t e d f o r the 1 mm difference  i n DMD  the  few  first  might be  greater  1978).  the  1 mm  than  the  2 mm  milling  size  Clumping of f e e d s u b s t r a t e s w i t h i n the bag  size grind.  the  was  Weakley et^ a l . (1983) found the g r e a t e s t  between feeds  h o u r s and  expected.  for  with losses  of d i f f e r e n t p a r t i c l e  overall  size  d i f f e r e n c e s were not  occurred as  large  in as  There was some i n d i c a t i o n t h a t t h e i n d i v i d u a l a n i m a l a f f e c t s NBDMD. Nocek (1985) r e p o r t e d t h a t h i s d a t a suggested v a r i a t i o n w i t h i n a n i m a l s i n r u m i n a l f e r m e n t a t i o n p a t t e r n s and t h a t t h e i n c l u s i o n o f a s t a n d a r d f e e d may  be n e c e s s a r y  t o monitor  the v a r i a t i o n .  Mehrez and Orskov  (1977)  found t h a t t h e g r e a t e s t s o u r c e o f v a r i a t i o n i n t h e i r study was t h a t due to  test  animal  f o l l o w e d by day o f t e s t .  between t e s t bags.  Weakley e£ a l .  The l e a s t  difference  occured  (1983) d i d not o b s e r v e any s i g n i f i c a n t  d i f f e r e n c e s among cows and i n d i c a t e d t h e r e may be no need t o be concerned w i t h t h e a n i m a l e f f e c t s on NBDMD i n s u b s t r a t e s s i m i l a r However, t h e s e a u t h o r s d i d f i n d  a significant  t o soybean meal.  difference  due t o a n i m a l  d i e t w i t h DM d i s a p p e a r a n c e b e i n g lower f o r those a n i m a l s b e i n g f e d a h i g h c o n c e n t r a t e r a t i o n and s p e c u l a t e t h a t t h i s may be due t o b a c t e r i a l s l i m e sealing  t h e pores  Lindberg to  (1981a,  basal diets  and b l o c k i n g  the i n f l u x  1981b) a l s o found s i g n i f i c a n t although  of d i g e s t i v e  d i f f e r e n c e s i n NBDMD due  t h e r e was some v a r i a b i l i t y  s u b s t r a t e b e i n g examined.  organisms.  depending  on t h e  F o r example, bags c o n t a i n i n g hay and sugar  b e e t p u l p d e c r e a s e d i n DMD when t h e amount o f roughage o f the b a s a l d i e t d e c r e a s e d w h i l e w i t h f i s h meal t h e r e was a tendency DMD.  Straw  diets.  and g r a i n s showed no s i g n i f i c a n t  towards  difference  increasing  between b a s a l  L i n d b e r g (1981b) r e l a t e d t h i s t o changes i n rumen a c t i v i t y as t h e  microbial  population  shifts  from  fibre  digesting  t o a m y l o y t i c and  s a c c h a r o l y t i c organisms.  Rode and S a t t e r (1984) c o n c l u d e d t h a t t o reduce  variability  t o use a n i m a l s e a t i n g a r a t i o n  i t was b e s t  feeds b e i n g e v a l u a t e d . increasing  t h e time  Mehrez  and  of incubation  s u b s t a n t i a l l y reduce v a r i a b i l i t y . of  introducing  and removing  Orskov from  7  (1977) t o 24  similar  to the  reported  that  hours  did  not  Nocek (1985) i n d i c a t e d t h a t the method  t h e bags  in a  time  series  affected  disappearance. removed  a t once  intervals. at  Bags were e i t h e r i n t r o d u c e d a t s p e c i f i c i n t e r v a l s and a l l or a l l inserted  a t once  and removed  at  specific  When bags were i n s e r t e d a t s p e c i f i c i n t e r v a l s and a l l removed  once t h e r e was a s l i g h t l y  f a s t e r r a t e c o n s t a n t and a s l i g h t l y  lower  variations i n results. There may be d i f f e r e n c e s i n r e s u l t s technique  (Weakley  due t o d i f f e r e n c e s i n washing  et_ a l . , 1983).  Washing  caused  the loss  of  p o t e n t i a l l y degradeable w a t e r s o l u b l e components o f t h e s u b s t r a t e ( H o v e l l et  a l . , 1986). However, i f t h e d e g r a d a t i o n c h a r a c t e r i s t i c s were  similar  to  t h e m a t e r i a l l e f t i n t h e bags t h e c o r r e c t i o n would be s m a l l . Weakley  et a l . (1983) i n d i c a t e d t h a t most a u t h o r s have found l i t t l e d i f f e r e n c e i n washing l o s s e s between days. De F a r i a  and Huber  (1984) , i n comparing NBDMD and IVDMD  results  found t h a t t h e two methods c o n s i s t e n t l y ranked t h e f o r a g e s b e i n g s t u d i e d in  t h e same  levels  order  b u t t h e NBDMD  of disappearance.  technique  There was h i g h  yielded  correlation  higher  percentage  between  the  two  t e c h n i q u e s when t h e bags were removed a t 48 and 72 hours b u t o n l y a l o w c o r r e l a t i o n when t h e bags were removed a t 24 h o u r s . quality  hay would have  t o be r e t a i n e d 3 t i m e s  T h e r e f o r e , a poor  as l o n g i n s i t u  as t h e  o t h e r b e t t e r q u a l i t y hays t o o b t a i n r e s u l t s s i m i l a r t o those o b t a i n e d i n vivo.  This  measurements  emphasizes  made  with  a  the d i f f i c u l t y fixed  time  i n relating  period  t o apparent  degradation i n vivo  digestibility. L i n d b e r g (1982c) found t h e d e g r a d a t i o n r a t e measured w i t h n y l o n bags was an o v e r - e s t i m a t e o f a c t u a l d e g r a d a t i o n a t any g i v e n time s i n c e t h e feed p a r t i c l e s a r e prevented the  degradation  from l e a v i n g t h e rumen.  characteristics  of d i f f e r e n t  feeds  This implies that  c o u l d be o f g r e a t e r  nutritional  significance  than  the d i l u t i o n  r a t e from  the i n d i v i d u a l d e g r a d a t i o n r a t e w i l l a f f e c t d i l u t i o n  t h e rumen because  rate.  2.5.4 CHEMICAL SYSTEMS The  objective  of  laboratory  c o m p o s i t i o n o f a f e e d from w h i c h made. the  analyses  was  to  determine  the  an e s t i m a t e o f a n i m a l response w i l l be  S i n c e t h e n u t r i t i v e v a l u e o f a f o r a g e was a f f e c t e d by c o m p o s i t i o n , problem  of  practical  evaluation  through  chemical  dependent upon t h e u n d e r s t a n d i n g o f t h e fundamental factors thing  controlling  as a b e s t  complex  and  indigestible contents  the a v a i l a b i l i t y  method  there  was  because no  f r a c t i o n of t h e f e e d  are e s s e n t i a l l y  unavailable problem,  chemical  method  available  components o f a f e e d a r e found therefore,  was  There was no  aspects that  will  isolate  the  1980)  Cell  determining  to the animal  within  the  the c e l l  portion  such  of q u a l i t y are  (Van Soest and R o b e r t s o n ,  completely  was  p h y s i c a l and c h e m i c a l  of n u t r i e n t s .  the n u t r i t i v e  analysis  while the wall.  The  of  structural  meet  scientific  c a r b o h y d r a t e t h a t was u n a v a i l a b l e . An  adequate  criteria  system  of  analysis  b u t must a l s o be easy  must  t o complete  competitive w i t h the proximate  analysis  those  variation  factors  unassayed response  affecting  factor  will  (Van Soest  feed  result  not only  and e c o n o m i c a l  system. since  I t must a l s o variation  i n an u n s a t i s f a c t o r y  and R o b e r t s o n ,  1980).  so as t o be  estimate  due  reflect t o an  of animal  S i n c e c h e m i c a l a n a l y s i s was  g e n e r a l l y l e s s e x p e n s i v e and f a s t e r t h a n a n i m a l s t u d i e s t h e use o f t h e s e techniques 2.5.4.1  i n a s s e s s i n g f e e d v a l u e was i n d i s p e n s i b l e  (Van S o e s t ,  1982).  VAN SOEST FIBRE SYSTEM  Due t o g e n e r a l d i s s a t i s f a c t i o n w i t h t h e Weende ( p r o x i m a t e a n a l y s i s ) system,  and t h e CF a n a l y s i s t e c h n i q u e and NFE c a l c u l a t i o n i n p a r t i c u l a r ,  Van  Soest  (1967)  pointed  techniques.  There  established  procedures  still  remains  out  has  been  despite  i n use  even  the a  need  new  conservative  obvious  though  for  chemical  tendency  limitations  problems  and  have been  analysis  to the  rely CF  long  on  method  recognized  (Crampton and Maynard, 1938). To loss  overcome  of  lignin  the  problems  i n the  of  filtrate  to  detergents  proposed (Van S o e s t ,  the  problems  techniques  with  the  which l e f t  CF  nitrogenous  CF  technique  when u s i n g  determination was  remove  the  sodium h y d r o x i d e  consistuents)  1963a).  technique  and  I t was those  a l a r g e p o r t i o n of  alkaline  conditions  polysacharides,  a  method  intended of  using  t o overcome  earlier  detergent undissolved  fraction.  and  quaternary  p r o t e i n s and  ammonium  compounds  nucleic acids resulting  i n the  dissolve preparation  The use o f a d e t e r g e n t  p l a c e o f NaOH under m i l d e r c o n d i t i o n s t h a n those of the CF t e c h n i q u e i n a d d i t i o n , help preserve  of  fractions.  into  nutritionally  The  indigestible  n e u t r a l detergent the  the i n t e g r i t y of the l i g n i n  o b j e c t i v e of the d e t e r g e n t  forages  fibre  acid.  The  while  the  into  (ND)  those  acid  non-carbohydrate  a n a l y s i s system was  a v a i l a b l e and p o r t i o n of  the  the  solubles  f e e d was  include hemicellulose  include  cellulose  fractions including lignin.  and  and the  AD  may,  fractionation  nutritionally  f r a c t i o n s t h a t a r e s o l u b l e and  in  fraction.  r e s i d u e w h i l e the a c i d d e t e r g e n t  insolubles  CF  f a c i l i t a t e the s o l u t i o n of p r o t e i n s i n s l i g h t l y  of f i b r e r e s i d u e s w i t h low N c o n t e n t s i n f e e d .  The  and  i n the  the p l a n t p r o t e i n  r e s u l t i n g i n an i n a c c u r a t e e s t i m a t i o n of the f i b r e Anionic detergents  (gelatinization  unavailable  recovered (AD)  in  the  step d i v i d e s  insoluble in a 1 N cell  wall protein  least  fibre  (ADF)  digestible was  u s e f u l as an i n i t i a l s t e p f o r the s e q u e n t i a l e s t i m a t i o n o f l i g n i n ,  also cutin,  cellulose,  indigestible  nitrogen  and  silica  (Van  Soest  and  Robertson,  1980). Neutral  detergent  fibre  (NDF)  estimates  the p l a n t c e l l w a l l making  i t a u s e f u l t o o l f o r e s t i m a t i n g feed i n t a k e . digestibility  since  different  fibre  prediction  of  plant  cell  constituents.  digestibility  c e l l w a l l c o n s t i t u e n t s (Van a q u i c k method of manner t o CF  Thus,  i s that  of  Soest and  determining  vary  in  the  estimating  problem the  f i b r e i n f e e d s and  was The  due  ADF  with  any of  was  used as  used i n a  similar  use  of  the ADF  t h e o r e t i c a l b a s i s other  Heat damanged p r o t e i n s are  of to  digestibility  R o b e r t s o n , 1980).  not founded on any  association.  digestibility  major  i n the p r o x i m a t e a n a l y s i s system.  p r e d i c t d i g e s t i b i l i t y was statistical  walls  I t g i v e s a poor e s t i m a t e  to than  a l s o recovered  In  the f i b r e , s p e c i f i c a l l y the l i g n i n f r a c t i o n s . Van  Soest  digestibility fibre  (1963b)  reported  f o r 18 f o r a g e s  ( r = -0.79  f o r ADF  n u t r i t i o n a l v a l u e and was  and  and  solubles  t h i s a n a l y s i s may a  ND  r e s u l t of NDF size  important  r = -0.73  CF  respectively) i n  with  estimating  i s o l a t e s the s l o w l y d i g e s t i n g components (cell  contents)  Mertens  (1983)  NDF  component  was  related  to  intake  i n r a t i o n formulations.  b e i n g r e l a t e d t o the b u l k d e n s i t y of f e e d s and  reduction  ADF  suggested  be a method of c h o i c e f o r e s t i m a t i n g d i g e s t i b i l i t y  theoretical perspective.  potentially  c o r r e l a t i o n of  u s e f u l i n estimating forage d i g e s t i b i l i t i e s f o r  S i n c e NDF  the  the  showed i t to be "somewhat s u p e r i o r " t o crude  ration formulations. measures  that  t h a t must o c c u r b e f o r e  feed  can  and  was  This the  from  was  the  particle  escape from the  rumen.  These f a c t o r s are of g r e a t e s t i m p o r t a n c e when the p h y s i c a l l i m i t s of d i g e s t i v e t r a c t r e g u l a t e i n t a k e when i n t a k e l e v e l d e c r e a s e s and NDF increases.  Thus  NDF  was  useful  for  estimating  intakes  for  a  the  level ration  formulations. Since  Van  Soest's  problems w i t h the ADF and  Robertson  problems. greater  greater  first  t h a n 10%  paper  The  on  the  detergent  note  three  areas  involves  the  filtering  revolving of  exceeds the  capacity  starch  may  of  form  the a  also  cause  materials i n preparation  were  the  no  problems  sample s i z e was  filtering  with  solution  in  soluble hot  Materials with a  the  initial  ND high  grinding  of  volume of  ND  f o r the f i b r e a n a l y s i s .  difference  i n NDF  sample s i z e p r o v i d e d  same.  Soest  l i p i d s , w h i c h at l e v e l s  viscous  fat  s o l u t i o n and  around  d e t e r g e n t t o form  a l s o cause f i l t e r i n g problems.  There was  Van  t o i n a d e q u a t e l e v e l s of d e t e r g e n t i n the  s o l u t i o n t h a t can can  several  second i n v o l v e s p r o t e i n w h i c h , when p r e s e n t a t l e v e l s  Finally,  content  system  t e c h n i q u e s have been i d e n t i f i e d .  can r e s u l t due  than 30%  complexes.  and NDF  (1980)  The  w a t e r phase.  initial  There was  a  l e v e l s based  on  the  proportions  of  sample to  the  difference  i n NDF  r e f l u x e d i n d i f f e r e n t amounts of ND  reagent  l e v e l s when a s i m i l a r s o l u t i o n (Mascarenhas  F e r r e i r a e t a l . , 1983). In analysis CP,  and  the  CP.  a  study  of  the  chemical  system, C o l b u r n and ash  components of  residues  of  fibre  Evans (1967) found t h a t c e l l u l o s e , l i g n i n ,  accounted f o r 95%  of  the o r i g i n a l p l a n t c e l l u l o s e and  S i m i l a r r e s u l t s were o b t a i n e d  found the ND  the  by  B a i l e y and  Ulyatt  r e s i d u e s t o c o n s i s t of most of the h e m i c e l l u l o s e  6%  (1970)  of who  p l u s a l l of  the c e l l u l o s e . Jorgensen correlated al.  (1978)  et  al.  (1982)  (r=-0.65 f o r a l f a l f a indicated  t h a t ADF  found  NDF  and  intake  to  be  highly  and  r=-0.79 f o r g r a s s e s ) .  Rohweder et^  was  highly  i n vivo  (r=-0.83 i n pure legume s t a n d s and  -0.93  correlated with i n g r a s s e s ) as  a r e s u l t of  DDM a  study  o f a wide range o f temperate and s u b t r o p i c a l g r a s s e s  and a l f a l f a .  They r e p o r t e d t h e c o r r e l a t i o n between NDF c o n c e n t r a t i o n and i n t a k e ranged from lower  r=-0.32  t o -0.94 w h i c h v a r i e d w i t h  i n the s u b t r o p i c a l species  h i s examination  species  and l o c a t i o n and was  compared t o t h e temperate s p e c i e s .  In  o f l a b o r a t o r y methods f o r p r e d i c t i n g t h e OMD o f f o r a g e s  A e r t s e t a l . (1977) s t a t e d t h a t r e g r e s s i o n s w i t h t h e s e p a r a t e  cell wall  components (NDF, ADF, c e l l u l o s e and l i g n i n ) proved t o be i n s u f f i c i e n t l y accurate based  t o estimate  on t h e c e l l  signficantly methods  techniques.  This  was a l s o t r u e f o r summative  wall constituents.  less  using  OMD.  accurate  living Even  with  A l s o , the estimates  purely  chemical  micro-organisms  so, coefficients  of  o f OMD  procedures  including  NBDMD  determination  equations  than and  were with IVDMD  for cell  wall  c o n s t i t u e n t s , e x c e p t h e m i c e l l u l o s e and c e l l u l o s e , were g r e a t e r than  those  o b t a i n e d w i t h t h e Weende system f o r e s t i m a t i n g OMD. I n e x p e r i m e n t s t o d e t e r m i n e t h e optimum NDF c o n t e n t milk  production,  Mertens  (1983)  found  of forages f o r  no d i f f e r e n c e i n t h e NDF  level  between f o r a g e s s p e c i e s a t maximum m i l k p r o d u c t i o n even though ADF v a r i e d widely. intake,  Mertens  concluded  that  t h e NDF system p r o b a b l y  s i n c e NDF was h i g h l y accounts  p r o d u c t i v i t y due t o t h e e f f e c t s o f f o r a g e s formulate  rations.  formulation  by  f o r more v a r i a t i o n  that  i n animal  than o t h e r t e c h n i q u e s  J o r g e n s e n (1982) supported  indicating  correlated with  used t o  t h e use o f NDF i n r a t i o n  the hemicellulose  content  o f legumes,  g r a s s e s and b y - p r o d u c t feeds v a r i e s g r e a t l y , thus ADF does n o t a d e q u a t e l y represent important  the t o t a l  fibre  value  of f e e d s t u f f s .  Hemicellulose  was an  p a r t o f f i b r e w h i c h was o v e r l o o k e d by ADF o r CF d e t e r m i n a t i o n s .  They concluded  t h a t f i b r e r e q u i r e m e n t s cannot be quoted i n terms o f ADF  or CF because i t was t h e t o t a l  f i b r e content  (NDF) t h a t d e t e r m i n e s t h e  effects. 2.5.4.2  FONNESBECK SYSTEM  Fonnesbeck  (1976) i n d i c a t e d t h a t most o f t h e c h e m i c a l methods f o r  a n a l y s i s o f f e e d n u t r i e n t s have been adopted on t h e b a s i s o f l a b o r a t o r y precision  and  nutritional  ease  of  completion  evaluation.  without  More knowledge  satisfactory  of p l a n t  chemical  chemistry,  or  chemical  t e c h n o l o g y and a n i m a l n u t r i t i o n a l l o w f o r more comprehensive n u t r i t i o n a l evaluations.  Thus, p r o c e d u r e s t h a t a l l o w f o r a more p r e c i s e  of  t h e c h e m i c a l components o f a f e e d  be  more  greatly  efficient  as i t was d i g e s t e d by a n i m a l s w i l l  for predicting nutritive  i n t h e i r concentrations  separation  value.  Since  feeds  vary  o f i n d i v i d u a l c h e m i c a l components, those  w h i c h i n v o l v e t h e major d i g e s t i b l e energy s o u r c e s ( s o l u b l e c a r b o h y d r a t e s , p r o t e i n and f a t s ) o r t h e d i l u t i n g compounds ( c e l l u l o s e , h e m i c e l l u l o s e and l i g n i n ) i n t h e i r purest  form may more a c c u r a t e l y  p r e d i c t the d i g e s t i b l e  energy c o n t e n t o f f e e d s i n g e n e r a l . Fonnesbeck Soest l e f t  (1976) s t a t e d  that  the n e u t r a l detergent  20-50% o f t h e n i t r o g e n r e m a i n i n g w i t h t h e f i b r o u s t i s s u e w i t h  an undetermined amount o f s t a r c h a l s o r e m a i n i n g . procedure  f o r separating  contributed  system of Van  nutritive  t o extreme f i l t e r i n g  from  This detracted  non-nutritive  problems when a n a l y s i n g  from t h e  components and energy  feeds,  p r o t e i n supplements and mixed d i e t s . A n o t h e r p r o c e d u r e was r e q u i r e d  that w i l l  accurately  f e e d s i n t o f r a c t i o n s used by a n i m a l s by a n a l y s i n g complex  components u s i n g  simple,  yet specific,  p a r t i t i o n the  f o r c a r b o h y d r a t e s as  a n a l y s i s when  standard  substances are not a v a i l a b l e . The  Fonnesbeck system  (Fonnesbeck and H a r r i s , 1976) s e p a r a t e s t h e  p l a n t t i s s u e i n t o c e l l w a l l s and c e l l  c o n t e n t s s i m i l a r t o t h e Van Soest  procedure. wall  The c e l l w a l l can t h e n be p a r t i t i o n e d i n t o t h e n u t r i t i v e  carbohydrates  and t h e n o n - n u t r i t i v e  components,  lignin  cell  and a c i d  i n s o l u b l e ash. Van Soest and R o b e r t s o n is  (1980) r e v i e w e d t h e system and i n d i c a t e d i t  n o t as q u i c k as t h e Van Soest  fibre fractions.  detergent  system  but obtained purer  They f e e l t h a t t h e n i t r o g e n removed from t h e c e l l w a l l s  was a s s o c i a t e d w i t h t h e i n s o l u b l e p r o t e i n t h a t was degraded  i n t h e rumen  r e s u l t i n g i n maximal p r o t e i n output and t h e r e f o r e was a r e a l e n t i t y .  As  w e l l , t h e system does n o t a l l o w t a n n i n s , c u t i n and M a i l l a r d p r o d u c t s t o be f r a c t i o n e d out o f t h e crude l i g n i n due t o a s h i n g . 2.5.4.3 THE SOUTHGATE SYSTEM The  newer  fibre  methods a r e o f l i m i t e d  s i n c e they were developed (1976) r e f e r s from  plant  to dietary  cell  walls  endogenous s e c r e t i o n s cell wall  f o r t h e ruminant fibre  value  i n human  nutrition  and, as a r e s u l t ,  Southgate  as a p p l y i n g t o a l l c o n s t i t u e n t s d e r i v e d  i n the diet  which  a r e n o t d i g e s t e d by t h e  o f t h e human d i g e s t i v e  carbohydrates are not a v a i l a b l e  tract.  Since the plant  t o man, t h e f i b r e  techniques  tend t o o v e r e s t i m a t e t h e p r o p o r t i o n o f c e l l w a l l than can be d i g e s t e d by man.  These  cellulose  indigestible  carbohydrates  and t h e n o n - c a r b o h y d r a t e  Southgate  (1969)  indicated  include  lignin  pectin,  material  the process  was  hemicellulose,  (Southgate,  technically  1973).  easy  to  p e r f o r m , r e q u i r e s o n l y s i m p l e a p p a r a t u s and t a k e s j u s t over f i v e w o r k i n g days  t o complete  chemical rather  a sample.  The p o l y s a c c h a r i d e s a r e determined  t h a n g r a v i m e t r i c a n a l y s i s and may be f u r t h e r s u b d i v i d e d  i n t o w a t e r - s o l u b l e and i n s o l u b l e s u b f r a c t i o n s . method  yields  using  a  virtually  complete  The r e s u l t s i n d i c a t e t h e  analysis  of  the u n a v a i l a b l e  c a r b o y h d r a t e i n f r a c t i o n s t h a t a r e i m p o r t a n t from b o t h a n u t r i t i o n a l and  c h e m i c a l p o i n t of v i e w .  Where a l t e r n a t i v e s  g i v e n f r a c t i o n a comparison wide v a r i e t y o f food In  a  critique  (1980) i n d i c a t e and  a r e a v a i l a b l e to measure a  of the a n a l y t i c a l methods compared w e l l i n a  stuffs. of  the  Southgate  t h a t the system  system,  does not  used  required.  was  very  f r a c t i o n a t i o n of  A l s o , even though a l t h o u g h  precise,  the  e x t r a c t i o n s are  the  and  Robertson  to r a p i d  not j u s t i f y  analysis  the time  and  the  analytical  equipment  not  definitive  in  their  carbohydrate.  Where sugar a n a l y s i s was that  Soest  lend i t s e l f  the p r e c i s i o n of the c h e m i c a l methods may  labour  Van  Southgate  system  r e q u i r e d , Van was  probably  Soest and R o b e r t s o n the  best  indicate  analytical  method  available.  2.6  SHEEP AS MODELS FOR  CATTLE  P l a y n e (1978) i n d i c a t e d t h a t i n t a k e and d i g e s t i b i l i t y v a l u e s f o r low q u a l i t y feeds s h o u l d not be e x t r a p o l a t e d t o c a t t l e from v a l u e s u s i n g sheep s i n c e low c o n c e n t r a t i o n s of N, in  poorer  utilization  However, the reasonably or  relative  of  these  difference  feeds  by  between  S and  other n u t r i e n t s  sheep forages  relative  to  f o r mature, low q u a l i t y m a t e r i a l s of low  (Heaney e_t a l . , 1980) .  result cattle.  in digestibility  c o n s t a n t r e g a r d l e s s of whether they are determined  c a t t l e except  determined  are  w i t h sheep  digestibility  R e l a t i v e d i f f e r e n c e s i n f e e d v a l u e of f o r a g e s a r e  s i m i l a r f o r the two a n i m a l s p e c i e s even though a b s o l u t e v a l u e s may and as a r e s u l t sheep d a t a can be a p p l i e d t o c a t t l e .  differ  CHAPTER 3 THE VARIETY TRIAL  3.1  MATERIALS AND METHODS I n order to assess  species  and  varieties,  grasses  and  legumes.  the v a r i a t i o n samples were  in nutritional s e l e c t e d from  quality a  of  l a r g e number  These f o r a g e s were t e s t e d as p a r t of the  Columbia Seed Crop E v a l u a t i o n P r o j e c t conducted B r i t i s h Columbia M i n i s t r y of A g r i c u l t u r e and  from 1981  Food.  forage  British  t o 1983  The  of  by  the  samples used i n  t h i s study were c o l l e c t e d a t Engen, B r i t i s h Columbia ( l o c a t i o n —  124°20'  west l o n g i t u d e , 54°3' n o r t h l a t i t u d e ) . The  species  and  varieties  s p e c i e s were p l a n t e d on May kg/ha  t e s t e d are  shown  28 and 29, 1980.  f o r a l l s p e c i e s except  orchard  The  i n Table  3.1.  All  s e e d i n g r a t e was  g r a s s which  was  11.2  planted at  13.4  kg/ha. Each s p e c i e s was w i t h each v a r i e t y  laid  out  replicated  i n a separate  f o u r times  s e t of p l o t s  on  the  i n a randomized complete  site block  design. Care was  t a k e n t o ensure a l l samples were h a r v e s t e d i n a c o n s i s t e n t  manner and a t s i m i l a r p h e n o l o g i c a l s t a g e over the study p e r i o d . were h a r v e s t e d  a t the e a r l y h e a d i n g  stage  and  legumes a t  Grasses  approximately  10% bloom. Harvest  0.9 the  d a t e s a r e shown i n T a b l e 3.2. 2  m s i c k l e mower t o sample a 2.79 sample  weighed  to  determine  m a  H a r v e s t i n g was  plot. fresh  The  done u s i n g a  p l o t s were raked  weight.  Grab  and  samples  of  a p p r o x i m a t e l y 500g were c o l l e c t e d , s t o r e d i n p l a s t i c bags and t r a n s p o r t e d to  the  cooler.  Prince  George  Subsequently  Experimental the  samples  Farm where were  dried  they at  were 42°C  placed for  48  in  a  hours  T a b l e 3.1  S p e c i e s and V a r i e t i e s Used i n T r i a l  Species Legumes A l f a l f a Alsike Clover Varieties Varieties Pacer  Tetra  Grasses Red C l o v e r Varieties Lakeland  Orchardgrass Varieties  Timothy Varieties  Kay  Climax  Peace  Pacific  Chinook  Salvo  Anchor  Altaswede  Sterling  Timfor  Sumas  Toro  Anik  T a b l e 3.2 H a r v e s t Dates f o r Samples o f t h e V a r i e t y  Species  Trial  Year 1982  1981  1983  Alfalfa A l l varieties  July 1  July 8  July 6  June 15  June 18  June 18  Orchard grass A l l varieties Timothy Variety  Alsike Variety Red  Climax Salvo Timfor Toro  June June June June  29 29 29 29  June June June June  29 29 29 29  June June June June  28 13 28 13  clover Tetra  July  17  June 29  June 28  clover  Variety  Lakeland Pacific Altaswede  June 29 June 29 J u l y 17  June 29 June 29 July 8  June 28 June 28 August 4  and  dry matter  yields  were  determined.  Once d r i e d ,  t h e samples were  s t o r e d i n paper bags i n an unheated b u i l d i n g . The in  samples s e l e c t e d f o r t h e v a r i e t y t r i a l were r e - s o r t e d from those  storage  and were  dried  a t 42°C  standard  No.3 W i l e y  mill  analysed  chemically  f o r n e u t r a l detergent  fibre  (ADF) , crude  disappearance  using  f o r 48 h o u r s and ground  a 1-mm  screen.  The samples were  fibre  p r o t e i n (CP) a n d , i n s i t u ,  through  (NDF), a c i d  a  then  detergent  f o r n y l o n bag d r y m a t t e r  (NBDMD).  The V a r i e t y T r i a l had two main o b j e c t i v e s : 1)  t o assess the v a r i a t i o n i n the n u t r i t i o n a l  quality  between f o r a g e s p e c i e s and v a r i e t i e s w i t h i n s p e c i e s , and 2)  t o assess the v a r i a t i o n i n the n u t r i t i o n a l q u a l i t y of f o r a g e s p e c i e s and v a r i e t i e s between y e a r s based on laboratory a n a l y t i c a l  3.1.1  procedures.  DETERMINATIONS As  d i s c u s s e d i n t h e L i t e r a t u r e Review, t h e r e a r e s e v e r a l l a b o r a t o r y  analytical  techniques  available  f o r d e s c r i b i n g feed  characteristics i n  o r d e r t o make an e v a l u a t i o n o f t h e q u a l i t y o f a f e e d .  Those  techniques  used i n t h i s study were chosen f o r s e v e r a l r e a s o n s .  The major f a c t o r was  the r e p r e s e n t a t i o n o f a u s e f u l f e e d c h a r a c t e r i s t i c  ( i e . NDF t o e s t i m a t e  i n t a k e o r NBDMD t o e s t i m a t e ease w i t h w h i c h  digestibility).  the a n a l y t i c a l  results interpretated.  Finally,  technique  The second f a c t o r was t h e  c o u l d be c a r r i e d  out and t h e  t h e NBDMD t e c h n i q u e was chosen t o more  f u l l y explore i t s p o t e n t i a l f o r e v a l u a t i n g feeds. Crude  protein  levels  q u a l i t y ) were determined Soil,  (one f a c t o r  i n assessing  overall  by t h e t e c h n i c a l s t a f f a t t h e B r i t i s h  Feed and T i s s u e T e s t i n g l a b o r a t o r y i n Kelowna, B r i t i s h  forage Columbia  Columbia.  Single  samples  were  analysed  using  a  Technicon  procedure  with  the  n i t r o g e n l e v e l s determined c o l o r i m e t r i c a l l y (AOAC, 1980). Acid  Detergent  Fibre  (ADF)  levels  (used  to  estimate  d i g e s t i b i l i t y ) were a l s o determined by t h e s t a f f a t the B r i t i s h S o i l , Feed and T i s s u e T e s t i n g l a b o r a t o r y . according  t o the t e c h n i q u e  outlined  by  forage Columbia  S i n g l e samples were a n a l y s e d Goering  and Van  Soest  (1970).  M o d i f i c a t i o n s i n c l u d e d t h e use o f 0.5 g o f s u b s t r a t e , 50 ml o f r e a g e n t , and  the e l i m i n a t i o n o f d e c a l i n from the ADF and NDF and sodium s u l p h a t e  from t h e NDF Dry  solution.  matter  determinations  were  done  using  approximately  1 g of  sample w h i c h was d r i e d a t 100°C f o r a t l e a s t 24 h o u r s . N e u t r a l d e t e r g e n t f i b r e l e v e l s (used t o e s t i m a t e f o r a g e i n t a k e ) were determined  a c c o r d i n g t o t h e method  outlined  (1970) as m o d i f i e d by Waldern (1971). for into  a l l samples.  digestibility)  dry matter were  done  using  and r e f l u x e d  for 1  solution.  determinations  a p p r o x i m a t e l y 4 x 8 cm which material  Soest  D u p l i c a t e d e t e r m i n a t i o n s were made  tube u s i n g an a n a l y t i c a l b a l a n c e  hour i n a p p r o x i m a t e l y 33 ml o f NDF bag  and Van  A p p r o x i m a t e l y 0.33 g o f sample was a c c u r a t e l y weighed  a tared test  Nylon  by G o e r i n g  nylon  (used  bags w i t h  to estimate inside  relative  dimensions  were f a b r i c a t e d u s i n g 40u pore  of  size Nitex  (B & S.H. Thompson and Co. L t d . , Town o f Mount R o y a l , Quebec).  The edges o f t h e bags were double sewn and t h e h o l e s s e a l e d u s i n g S i l i c o n S e a l (Dow C o r n i n g Canada L t d . , M i s s i s s a u g a , O n t a r i o ) . One  g samples were  a n a l y t i c a l balance.  a c c u r a t e l y weighed  into  a t a r e d bag u s i n g an  The bag had p r e v i o u s l y been d r i e d  a t 60°C f o r 24  h o u r s , t h e d r y i n g temperature was s e l e c t e d t o p r e v e n t damage t o the N i t e x m a t e r i a l due t o excess h e a t .  P r i o r t o w e i g h i n g , and d u r i n g t r a n s f e r  from  the  drying  oven t o t h e a n a l y t i c a l  balance, a l l  bags and samples were  placed i n a dessicator. The bottle  bags were  securely  by heavy n y l o n  attached  fishing  line  to a s a n d - f i l l e d  about 15 cm  100 m l  i n length.  plastic  To  reduce  problems w i t h bags a d h e r i n g t o each o t h e r i n t h e rumen o n l y 6 bags were attached placed  t o each  bottle  i n each a n i m a l .  animals  used  sample.  as  and  four  bottles  (a t o t a l  Each sample, was d u p l i c a t e d  replicates.  Thus  four  bags were  o f 24 bags) were i n each o f t h e two incubated  A l l samples were i n c u b a t e d f o r a 24 hour p e r i o d .  f o r each  The b o t t l e s  were p u t i n t o t h e a n i m a l t h r o u g h a f i s t u l a and were p l a c e d each time i n t o t h e v e n t r a l a r e a o f t h e rumen. two H e r e f o r d  steers weighing  The a n i m a l s used i n t h i s p r o c e d u r e were  550 and 600 kgs r e s p e c t i v e l y b e i n g  fed a  r a t i o n o f t i m o t h y hay a l o n g w i t h t r a c e m i n e r a l s a l t and w a t e r ad_ l i b i t u m . The  steers  were housed i n a h e a t e d  barn  and were f r e e  t o move about  w i t h i n the confines of the s t a l l . Once the b o t t l e s were removed from the rumen a t the end of the 24 hour  incubation  period  t h e bags  were  washed  quickly  to  remove  any  m a t e r i a l a d h e r i n g t o t h e o u t s i d e o f t h e bag and t h e bags were s t o r e d a t 4° C u n t i l  time was a v a i l a b l e f o r more c a r e f u l washing.  The bags were  removed from t h e b o t t l e s p r i o r t o b e i n g washed i n lukewarm w a t e r by hand u n t i l t h e wash w a t e r s t r a i n e d from t h e bag was c l e a r .  The bags were then  removed from t h e b o t t l e s and p l a c e d i n a d r y i n g oven a t 60°C f o r a t l e a s t 24 h o u r s , a f t e r w h i c h they were weighed u s i n g t h e a n a l y t i c a l b a l a n c e and the d r y m a t t e r d i s a p p e a r a n c e c a l c u l a t e d . 3.1.2  EXPERIMENTAL DESIGN AND STATISTICAL ANALYSIS NDF,  ADF  and CP a n a l y s i s r e s u l t s were s t a t i s t i c a l l y  the f o l l o w i n g l e a s t squares model:  analysed  using  Y. = u + V. + B.,., + T. + V.T, + e..,.,,, ljkl x j ( i ) k 1 k l(xjk) M 1  where Y  ^  = t h e dependent v a r i a b l e NDF, ADF o r CP  u = t h e o v e r a l l mean common t o a l l samples = the e f f e c t of the i ' t h v a r i e t y B,,,. = t h e e f f e c t o f t h e I ' t h p l o t - n e s t e d j(i) w i t h i n the i ' t h v a r i e t y T  ( f i r s t e r r o r term)  = the e f f e c t of the k'th year  fc  V/T^  = the i n t e r a c t i o n of the i ' t h v a r i e t y w i t h the k'th year  e.,,...' t h e u n e x p l a i n e d r e s i d u a l l(ijk) ^  error  a s s o c i a t e d w i t h each o b s e r v a t i o n . The  experimental  plot  i n time.  were  3 years  d e s i g n was a c o m p l e t e l y  The f a c t o r s  randomized  nested  a n a l y s e d i n t h e 3 x 16 f a c t o r i a l  and 16 v a r i e t i e s .  The same  least  squares  split  experiment model and  e x p e r i m e n t a l d e s i g n was used t o a n a l y s e Type and S p e c i e s e f f e c t s . NBDMD r e s u l t s  f o r v a r i e t y were a n a l y s e d u s i n g a s l i g h t l y  different  model due t o t h e u s e o f two a n i m a l s as r e p l i c a t e s . The f o l l o w i n g squares model was used f o r t h e a n a l y s i s :  Y  ijkr  =u + V + i +  e  B.,. + T . + V^T. + A r + V.,Ar + T. A r + V^ArT, 3 (i) k i k i k i k N  Kijkr)  where Y^^  =  t  h  e  dependent v a r i a b l e NBDMD  u = t h e o v e r a l l mean common t o a l l t h e samples  least  V.  the e f f e c t o f t h e i ' t h v a r i e t y  I  the e f f e c t of the j ' t h p l o t n e s t e d w i t h i n  j(i)  i'th variety  V.T. 1  term)  t h e e f f e c t of t h e k ' t h y e a r  k  T  ( f i r s t error  the  the i n t e r a c t i o n of the i ' t h v a r i e t y w i t h the  k  k'th year A  = t h e e f f e c t o f the r ' t h a n i m a l t h e i n t e r a c t i o n o f the k ' t h y e a r w i t h t h e r ' t h  k r  animal V.A T. x r k  the i n t e r a c t i o n of t h e i ' t h v a r i e t y , the r ' t h a n i m a l and t h e k ' t h y e a r  e  the u n e x p l a i n e d r e s i d u a l e r r o r a s s o c i a t e d  Kijkr)  w i t h each o b s e r v a t i o n .  The plot  in  experimental  d e s i g n was  time.  factors  experiment squares  The  were 2 a n i m a l s ,  model  and  a  completely  analysed  in  3 y e a r s , and  experimental  designs  the  randomized 2  x  3  x  16 v a r i e t i e s . was  used  to  nested 16  The  factorial same l e a s t  analyse  S p e c i e s e f f e c t s , however the number o f f a c t o r s were d i f f e r e n t . the  factors  were  2 Animals,  3 Years  and  2 Types and  split  Type  and  F o r Type  f o r ' Species  the  f a c t o r s were 2 A n i m a l s , 3 Y e a r s and 5 S p e c i e s . In  addition  to  the  analysis  carried  out  using  the  models d e s c r i b e d , t h e NBDMD r e s u l t s were a l s o m a n i p u l a t e d it  was  necessary  replications variety  or  c o u l d be  to  analyse  i f they  the  c o u l d be  composited  samples  using  composited.  by m i x i n g  t o g e t h e r and c o n d u c t i n g the a n a l y s i s  the  the  least  squares  t o determine i f field  plots  as  I f the samples f o r each  samples from each f i e l d  plot  of v a r i a n c e u s i n g the a n i m a l s as the  r e p l i c a t e s fewer NBDMD d e t e r m i n a t i o n s (4 p e r v a r i e t y i n s t e a d have  t o be done  reducing  the workload.  This  o f 16) would  assessment  of  field  r e p l i c a t i o n s v e r s u s a n i m a l r e p l i c a t i o n s was done u s i n g t h e d a t a from one y e a r , thus e l i m i n a t i n g  y e a r from t h e model.  a n a l y s i s were done based on t h e f o l l o w i n g The  first  model  (Case  described to analyse Variety was t h u s p l o t n e s t e d w i t h i n A  second  least  One) was  Two d i f f e r e n t l e a s t squares  models. t h e same  e f f e c t s by Y e a r .  as  that  previously  The e r r o r term f o r v a r i e t y  variety.  squares model was used  based on t h e mean v a l u e c a l c u l a t e d i n each o f t h e t h e t e s t s t e e r s  to evaluate  NBDMD  results  from t h e f o u r bags p e r v a r i e t y  (Case Two) .  placed  The r e s u l t was t h e same as  i f t h e samples from a l l p l o t s f o r a v a r i e t y were composited and d u p l i c a t e a n a l y s i s were done i n two a n i m a l s w i t h t h e a n i m a l s b e i n g t h e r e p l i c a t e s . Thus,  there  instead  were  only  four  bags  per variety  p e r Year  would  be used  o f t h e s i x t e e n used i n t h i s e x p e r i m e n t .  The  l e a s t squares model used i s : Y.. = u + V. + e. .  where Y „ = t h e dependent v a r i a b l e u = t h e o v e r a l l mean common t o a l l samples V. = t h e e f f e c t due t o t h e i ' t h v a r i b l e i e.. = t h e u n e x p l a i n e d r e s i d u a l e r r o r *3  associated  w i t h each o b s e r v a t i o n .  Prior grown  to pooling  standard  i n a separate p l o t  within  errors  between s p e c i e s  (since  each was  t h e e x p e r i m e n t a l area) a t e s t  homogeneity o f v a r i a n c e s was performed u s i n g t h e B a r t l e t t ' s t e s t  of  the  (Steel  and T o r r i e , 1980). L e a s t squares a n a l y s i s o f v a r i a n c e was done u s i n g t h e G e n e r a l L i n e a r Models  (GLM) p r o c e d u r e  unbalanced F values  (SAS, 1985) w h i c h  and m i s s i n g c e l l s . were  allowed  f o r manipulation  of  Those s o u r c e s o f v a r i a t i o n w i t h s i g n f i c a n t  t e s t e d f o r s i g n f i c a n c e by Student-Newman-Kuels m u l t i p l e  comparison o f means ( S t e e l and T o r r i e , 1980). 3.1.3  ASSESSMENT OF FEEDING VALUE According  to  Ulyatt  (1973)  the  feeding  value  of  forage  e s s e n t i a l l y , b u t n o t e x c l u s i v e l y based on i n t a k e and d i g e s t i b i l i t y . order  to assess  f e e d i n g v a l u e based  on i n t a k e and d i g e s t i b i l i t y  parameters were e s t i m a t e d u s i n g t h e f o l l o w i n g e q u a t i o n s  was In these  (Rohweder e t a l .  1985): 1)  DMD(%) = 88.9 - 0.779 x (ADF%), and  2)  DMI(g/kg B W * ) = 96.4 - 0.0003 ( C P % ) 0  75  0.04282(NDF%)-0.0085(NDF% ) 2  These  parameters  were  Index  (FVI) s i m i l a r  multiplied to that  o f Crampton  e q u a t i o n : F V I = (DDM x DMI)/100. for  together  t o develop  et a l . using  the  on t h e a s s u m p t i o n t h a t DM  importance 3.1.4  Value  following  The r e s u l t i n g FVI was used as a b a s i s  comparing d i f f e r e n c e s between s p e c i e s and v a r i e t i e s .  based  T h i s i n d e x was  i n t a k e and d i g e s t i b i l i t y  are of equal  i n determining the feeding value of a forage.  INTEGRATION OF FORAGE QUALITY AND YIELD In  Species  order  to i n t e g r a t e the y i e l d  and V a r i e t i e s  w i t h the r e s u l t s  results  f o r each  of t h e q u a l i t y  two c a l c u l a t i o n s were made u s i n g ADF and CP v a l u e s . used  a Feeding  i n an e q u a t i o n  developed  by M a t h i s o n  o f t h e Types, determinations,  The ADF v a l u e s were  e t a l . (1982) t o e s t i m a t e  d i g e s t i b l e energy (DE) DE The  (Mcals/kg)  subsequent DE  following  This equation i s :  = 3.44  e s t i m a t i o n was  - 0.22(ADF%)  used t o o b t a i n a DE y i e l d  (DEY)  i n the  equation; DEY  No  levels.  (Meals x 10 /ha) = DE x Y i e l d 3  s t a t i s t i c a l a n a l y s i s was  done f o r the DE  estimations since  i s a t r a n s f o r m a t i o n of the e x p e r i m e n t a l d a t a and t h e r e would be no  change  i n the s t a t i s t i c a l s i g n i f i c a n c e from t h a t o b t a i n e d u s i n g the f a c t o r upon w h i c h the DE e q u a t i o n was  mentioned  v a r i a n c e s was  i n Section  done p r i o r  study a r e a . The  RESULTS  3.1.1  Bartlett's  test  t o p o o l i n g the s t a n d a r d  ( o r s i t e s ) s i n c e each was  (ADF)  based ( S t e e l and T o r r i e , 1980). 3.2  As  this  f o r homogeneity  e r r o r s between  of  species  t e s t e d i n a d i f f e r e n t s e t of p l o t s w i t h i n the  t e s t i n d i c a t e d the v a r i a n c e s were s i m i l a r and the p o o l i n g  o f the s t a n d a r d e r r o r s was  l e g i t i m a t e . The  r e s u l t s are presented  by Type  (legume o r g r a s s ) , S p e c i e s  ( a l f a l f a , orchardgrass, timothy, a l s i k e c l o v e r  o r r e d c l o v e r ) and V a r i e t y . 3.2.1  YIELD Yield  d a t a were c o l l e c t e d by  J.N.  T i n g l e and  h i s s t a f f during  course of the B r i t i s h Columbia Seed E v a l u a t i o n P r o j e c t and were as p a r t of Table  this  study.  The  results  f o r Type and  analysed  are shown i n  3.3 For  Type,  over  a l l years,  there  ( P ^ . 0 . 0 1 ) i n y i e l d between legumes and 0.25  t/ha  respectively).  (P>0.05) i n y i e l d 1982  Species  the  and  1983  Within  between the  two  legumes s i g n i f i c a n t l y  was  a  grasses years,  forage  significant (4.58  there  types  ± 0.25 was  i n 1981  no  difference v s . 3.63  ±  difference  while i n both  (P^O.01) o u t - y i e l d e d grasses.  T a b l e 3.3 L e a s t Square Means ± SEM^' o f Forage Y i e l d s by Type and S p e c i e s YIELD (t/ha) Year Designation  1981  1982  All Years  1983  Type Legumes Grasses  4.52±0.40 4.15±0.40  a a  2.86±0.20 1.53±0.19  b  1  C  O  A  A  , n S  a  6.37±0.29 5.17±0.29  b 3  4.58t0.25 3.63l0.25  b a  Species Alfalfa Orchardgrass Timothy A l s i k e Clover Red C l o v e r  3.38±0.41 2.49+0.40 5.9310.42? 6.9610.80? 5.18+0.49  a 3  1.95±0.23 1.33±0.21 1.75±0.22 3.8610.43;* 3.6510.26 a  a  a  6.71±0.35 4.10±0.35 6.2510.35 . 4.94l0.70 6.4010.43  11 SEM=Standard E r r o r of t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and designation are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  a  a  3.9810.29 2.64i0.28 4.6210.29 5.2510.56^ 5.1110.34 a  DC  When clover (3.98  the r e s u l t s  (5.25 ± 0.50 ± 0.29  were  analysed  t/ha) s i g n i f i c a n t l y  t/ha), orchardgrass  t/ha) b u t was not s i g n i f i c a n t l y  0.34  t/ha).  ( P ^ O . O l ) forage were s i m i l a r from  timothy,  than a l f a l f a  (P ^ 0 . 0 1 )  and  yielding  from  and r e d cover  r e d c l o v e r (5.11 ±  The r e s u l t s  more  from  different  and o r c h a r d g r a s s .  significantly  (4.62 ±  r e d c l o v e r produced  and o r c h a r d g r a s s .  alfalfa  alsike  out-yielded a l f a l f a  t/ha) and t i m o t h y  different  alsike  f o r a l l years  i n t h a t t i m o t h y was n o t s i g n f i c i a n t l y  t h e lower  timothy  1981  Species  (2.64 ± 0.28  0.29  In  by  1982  (P>0.05)  I n 1983,  out-yielded orchardgrass  alfalfa,  (P^O.Ol)  w h i l e a l s i k e c l o v e r y i e l d s were i n t e r m e d i a t e . When a n a l y s e d by v a r i e t y there  was  no  significant  w i t h i n s p e c i e s a c r o s s a l l y e a r s ( T a b l e 3.4)  difference  (P>0.05)  between  orchardgrass,  a l f a l f a o r t i m o t h y v a r i e t i e s . However, t h e r e was a d i f f e r e n c e between r e d clover varieties Lakeland  and  respectively).  (P^0.05). Altaswede  I n t h i s case P a c i f i c y i e l d e d much l e s s (2.4±0.10,  Altaswede In  difference  (P ^ 0 . 0 5 )  between  Again,  timothy  t h e r e was  red clover v a r i e t i e s  d i f f e r e n c e between v a r i e t i e s  or orchardgrass  Altaswede  (P>0.05)  significantly  but w i t h i n  out-yielded  s i g n i f i c a n t l y h i g h e r y i e l d than P a c i f i c v a r i e t y varieties  were n o t s i g n i f i c a n t l y d i f f e r e n t  significantly  (P^0.05).  out  performed  Salvo  Lakeland (P^0.05).  i n 1983. and  Toro  t/ha  (P>0.05)  out-performing Lakeland which o u t - y i e l d e d the P a c i f i c  varieties  Timfor  7.9±0.09  difference  or timothy v a r i e t i e s .  1982 t h e r e was no s i g n i f i c a n t  alfalfa,  and  Over a l l y e a r s , i s no s i g n i f i c a n t  between o r c h a r d g r a s s , a l f a l f a significant  4.9±0.10  than  a  with  variety.  f o r either  the r e d c l o v e r which  had  a  Orchardgrass  However, C l i m a x and timothy  As i n each o f t h e p r e c e d i n g y e a r s , Altaswede  varieties  significantly  T a b l e 3.4 L e a s t Square Means + SEM  o f Forage Y i e l d s by V a r i e t y  YIELD (t/ha) Species and Variety  1981  Alfalfa Pacer Anchor Peace Anik  3.3+0.5 3.0±0.5^ j 3.6i0.6 3.7±0.5  2.0±0.4 1.7+0.3 1.9±0.3 2.4±0.4  Orchardgrass Kay Chinook Sterling Sumas  3.0i0.5 2.4±0.5 ^ 2.110.5*? 2.4±0.5  1.7±0.3 l.l+0.3 1.4±0.3 1.0±0.3  Timothy Climax Timfor Salvo Toro  6.3i0.5 jl 6.2±0.5" 5.710.5* . 5.4±0.6  2.0±0.3 1.9±0.3 1.7±0.4 1.4±0.3  7.0±0.5  3.9±0.3  Alsike Tetra  Year 1982  abc D  b c d  bcd  a b c  a  C  abc  e  def  A l l Years  1983  6.8±0.4^ , 6.2±0.4 6.1±0.4 7.710.4  4.0±0.1 £ 3.6±0.1 3.7±1.0 4.6±0.1  4.4±0.4 3.8+0.4 , 4.2±0.4 4.0±0.4  3.0±0.l 2.5+0.1 2.610.l 2.510.l  7.4±0.4 7.6+0.4 . 5.3+0.4 4.7±0.4  5.2i0.1 5.210.C . 4.210.l 3.910.l  b  5.0±  5.3+0.1  b  6.2+0.4 9.7±0.4 4.2±0.4  a a a  a  a  d  bcd bcd  ab  a  a  a a  a a a a  aD  a  d  abG  ab  b  abc  cd  ab  a  a a  d  b G d  b c d  clover  Red c l o v e r Lakeland Altaswede Pacific  f  4.6±0.5 8.7±0.5 1.2+0.6* 8  cde  3.6±0.4 5.2±0.3 2.1±0.3  C  a  a b c  bcd  e  ab  1f SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column a r e significantly different (P^0.05).  d  abc  4.9t0.1 7.910.1 2.4+0.l  d  c d 6  a  o u t - y i e l d e d L a k e l a n d and P a c i f i c v a r i e t i e s ( P . ^ 0 . 0 5 ) . O v e r a l l , Altaswede  r e d ^ c l o v e r was c o n s i s t e n t l y t h e h i g h e s t y i e l d i n g  f o r a g e on t e s t p r o d u c i n g 8.7 ± 0.5, 5.2 ± 0.3 and 9.7 ± 0.4 t / h a f o r a l l years  respectively.  In  addition,  only  the  red  clovers  showed  a  s i g n i f i c a n t d i f f e r e n c e i n y i e l d s between v a r i e t i e s . There was a s i g n i f i c a n t d i f f e r e n c e f o r Type, S p e c i e s and V a r i e t y  i n yield  among Y e a r s  (P^O.Ol)  ( T a b l e 3.5) w i t h t h e y i e l d b e i n g h i g h e s t i n  1983 and l o w e s t i n 1982 ( P ^ 0 . 0 5 ) . • There were s i g n i f i c a n t Type, S p e c i e s and V a r i e t y  x Year  (P^O.Ol)  interactions. 3.2.2 CRUDE PROTEIN Over a l l y e a r s and w i t h i n each y e a r legumes had s i g n i f i c a n t l y h i g h e r (P<!0.01) l e v e l s of crude p r o t e i n than g r a s s e s (13.7±0.21% v s 9.8+0.21%) (Table 3.6). CP l e v e l s between over a l l y e a r s except o r d e r were a l f a l f a clover  S p e c i e s were s i g n i f i c a n t l y  different  f o r a l s i k e c l o v e r and r e d c l o v e r .  (14.0 ± 0.22%),  (13.2 + 0.25%), o r c h a r d g r a s s  0.22%). I n 1981 t i m o t h y  a l s i k e clover  (P.^0.01)  I n descending  (14.0 ± 0.42%), r e d  (10.8 ± 0.22%) and t i m o t h y  l e v e l s were s i g n i f i c a n t l y  lower  (8.8 ±  (P^0.05)  than  o r c h a r d g r a s s o r a l f a l f a w h i c h , i n t u r n , were s i g n i f i c a n t l y lower t h a n t h e clover levels. that  S i m i l a r r e s u l t s were o b t a i n e d i n 1982 w i t h t h e e x c e p t i o n  t h e r e was no s i g n i f i c a n t d i f f e r e n c e  c l o v e r which different  had t h e h i g h e s t CP l e v e l .  Each S p e c i e s was  ( P ^ O . 0 1 ) f o r CP i n 1983 i n t h e d e s c e n d i n g  C l o v e r , O r c h a r d g r a s s , and Timothy By  ( P > 0 . 0 5 ) between a l f a l f a and  variety  significantly  across  ( P ^ [ 0.05)  order of A l f a l f a ,  (P^0.05).  a l l years lower  significantly  CP  o r c h a r d g r a s s a l s o had s i g n i f i c a n t l y  (Table  3.7)  l e v e l s than lower  Timfor  Toro.  timothy  Kay and  had  Chinook  l e v e l s o f CP t h a n Sumas w i t h  T a b l e 3.5 L e a s t Square Means ± SEM and NBDMD L e v e l s by Y e a r  o f Y i e l d , CP  , NDF, ADF,  Determinations  11 n  Yearll  Yield  1981  4.25  1982  2.19  1983  5.83°  SEM  0.1  CP  NDF  ADF  NBDMD  b  10.3  a  53.5  a  32.7  a  72.3  a  a  11.8  b  55.7  b  32.0  a  72.8  a  56.6  b  32.7  a  72.4  a  13.1  C  0.1  0.4  0.3  SEM=Standard E r r o r o f t h e Mean CP=Crude P r o t e i n , NDF=Neutral D e t e r g e n t F i b r e , ADF=Acid D e t e r g e n t F i b r e NBDMD=Nylon Bag Dry M a t t e r D i s a p p e a r a n c e a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s w i t h i n columns a r e significantly different (P^0.05).  0.3  T a b l e 3 . 6 L e a s t Square Means ± SEM and S p e c i e s  o f Crude P r o t e i n L e v e l s by Type  Crude P r o t e i n L e v e l  Year Designation  1981  1982  All Years  1983  Type Legumes Grasses  11.2±0.33 9 4±0 32^ b  13.6±0.24  b  ** 10.0±0.23  £  1n  f  ri  16.3±0.34 <"> 9 rij-rv o;.* .9±0. 34  b  £  13.710.21* n 9 oj.r\ .8±0.21 a  Species Alfalfa Orchardgrass Timothy AA l1 s_ i k1.e_ C l o v e r Red C l o v e r  10.4+0.32? 11.0±0.31 ^ 7.8±0.32 * 11.0±0.63 12.3±0.38 Q  n  0 0  a  C  13.4±0.29f  18.0±0.33^  14.010.22^  10.9±0.27  10.4±0.33  10.8±0.21  b  8.8±0.22  a  9.0±0.28  a  9.3±0.33  14.3±0.54  C  16.7±0.66  13.5±0.32  c  13.9±0.38  If SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and designation are s i g n i f i c a n t l y d i f f e r e n t (P^0.05).  a  14.0±0.42 C  13.2±0.25  C  c d  T a b l e 3.7 L e a s t Square Means ± SEM  o f Crude P r o t e i n L e v e l s by V a r i e t y  Crude P r o t e i n (%) Species and Variety  1981  Alfalfa Pacer Anchor Peace Anik  10.1+0.5 ° 10.0i0.5 ° 11.5+0.6 ~ j 10.4+0.5  Orchardgrass Kay Chinook Sterling Sumas  9.3+0.5 ° 10.810.5° 11.6i0.5 12.2+0.5  Year  Timothy Climax Timfor Salvo Toro Alsike Tetra  1982  b  d  b  d  ab  de  8.0±0.5 7.5+0.5 7.6±0.5\ 8.5±0.6 ab 3  abG  12.7±0.6 13.310.5° 13.8±0.5T 14.0+0.6  cde  e  de  d  All Years  1983  10.4+0.5 10.4±0.5 £ 11.3+0.5 ° 11.6±0.5 ab  a  ab  bcd  8.9+0.5 9.0±0.5 9.1±0.6 9.2±0.5  3  17.3±0.6 18.6+0.6*: 18.8+0.67 17.2+0.6  13.5+0.l 14.010.l r 14.8+0.14r 13.8+0.I  10.5±0.6 9.6±0.6 10.610.6? 11.010.6  io.no.i 10.210.1° 11.2+0.1 ® 11.6+0.1  8.6±0.6 7.9±0.6 10.1i0.6 10.910.6  8.510.l 8.1±0.1 8.910.l 9.510.l °  d  b  ab  ab  a  a  b  a  a  gb  8  8  c d  ab  a  abC  b  clover  Red c l o v e r Lakeland Altaswede Pacific  11.0±0.5  d  de 12.410.5° 11.3+0.5 13.5+0.6 6  14.3±0.5  16.7t0.6  e  14.5+0.6  e  13.3±0.5 J C  13.0+0.5  e  d  14.010.6° 13.110.6 14.810.6°  C  1[ SEM=Standard E r r o r o f t h e Mean. a,b Means i n each column w i t h d i f f e r e n t s u p e r s c r i p t s a r e significantly different (P^0.05).  14.010.l  gh  13.510.1 * 12.5+0.1 13.6+0.1 8  1  8  8  Sterling  variety  being  intermediate. Overall,  d i f f e r e n c e between a l f a l f a The  result  (P3>0.05) red  signficiant  o r between r e d c l o v e r v a r i e t i e s  (P>0.05).  variety  f o r 1981  showed  between t i m o t h y , o r c h a r d g r a s s  clover  had s i g n i f i c a n t l y h i g h e r  than  Lakeland  Tetra  alsike  differences red  by  t h e r e was no  (12.4 ± 0.5%) clover  no  significant  or a l f a l f a v a r i e t i e s .  ( P ^ 0 . 0 5 ) CP l e v e l s  o r A l t a s w e d e (11.3 ± 0.5%)  (11.0 ± 0.5%).  difference  I n 1982  Pacific  (13.5 ±  red clovers or  t h e r e were no  significant  (PJ>0.05) i n CP l e v e l f o r t i m o t h y , o r c h a r d g r a s s , a l f a l f a o r  clover v a r i e t i e s .  significantly  lower  However  i n 1983 C l i m a x and T i m f o r v a r i e t i e s  were  ( P ^ 0 . 0 5 ) i n CP l e v e l than S a l v o and Toro v a r i e t i e s .  There was no d i f f e r e n c e between o r c h a r d g r a s s , c l o v e r o r a l f a l f a (P>0.05)  0.6%)  f o r CP l e v e l .  varieties  O v e r a l l , t h e a l f a l f a v a r i e t i e s and T e t r a a l s i k e  c l o v e r had t h e h i g h e s t CP l e v e l s , however, t h e r e was  little  difference  between CP l e v e l s o f v a r i e t i e s f o r a g i v e n s p e c i e s . There years  was  a  (P^O.01)  significant  difference  i n overall  w i t h t h e h i g h e s t l e v e l i n 1983  CP  levels  between  (13.1 ± 0.13%) and the  l o w e s t i n 1981 ( T a b l e 3 . 5 ) . There were s i g n i f i c a n t i n t e r a c t i o n s  ( P ^ O . 0 1 ) f o r Type, S p e c i e s and  V a r i e t y by Y e a r . 3.2.3  NEUTRAL DETERGENT FIBRE The r e s u l t s  Table  3.8.  f o r t h e NDF Overall  a n a l y s i s f o r Type and S p e c i e s a r e shown i n  years,  and  s i g n i f i c a n t l y h i g h e r ( P ^ O . 0 1 ) NDF  within  levels  years,  the  grasses  had  than t h e legumes (64.3 ± 0.64  v s . 46.1 ± 0.65%). When  examined  by  significantly different  Species  over  a l l years,  each  Species  was  than t h e o t h e r s ( P ^ O . 0 1 ) w i t h c l o v e r s h a v i n g t h e  T a b l e 3.8 L e a s t Square Means ± SEM^' o f N e u t r a l D e t e r g e n t by Type and S p e c i e s  Fibre Levels  N e u t r a l Detergent F i b r e L e v e l s (%) Year Designation  1981  All Years  1982  1983  44.5±0.59' 66.4±0.57  47.0+0.90 66.3±0.87  44.4+0.63 65.1+0.59 67.9±0.63 38.6±1.17*' 47.0+0.74 c  49.0+1.23 64.5+1.23 68.1±1.23 41.2±2.60 a 45.7±1.36 ab  Type Legumes Grasses  47 .l±l.ll 60 .1+1.09  a  a  46.1±0.65 - * 64.3±0.64  c/  Q  A  a  t A  Species Alfalfa Orchardgrass Timothy A l s i k e Clover Red C l o v e r  51.0±0.99 55.0±0.96*r 65.5±0.99 46.5±1.91 42.1±1.15  a a  C  {  C  C  48.1±0.63 61.5+0.61*: 67.1±0.63 42.2±1.27 44.8±0.75  % SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and d e s i g n a t i o n are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  a  a  lowest  level  (42.2 ± 1.27 and 44.8 ± 0.75% f o r a l s i k e  respectively) 0.63%), The  alfalfa  next  (48.1 ± 0.65%),  then  and r e d c l o v e r  orchardgrass  f o l l o w e d by t i m o t h y w i t h t h e h i g h e s t NDF l e v e l  (61.5 ±  (67.1 ±  0.65%).  r e s u l t s were a l s o t h e same by y e a r ( P ^ O . 0 1 ) w i t h t h e e x c e p t i o n t h a t  a l f a l f a ranked i n t e r m e d i a t e between a l s i k e and r e d c l o v e r i n 1982. NDF l e v e l s by v a r i e t y was a s i g n i f i c a n t varieties  with  a r e shown i n T a b l e 3.9.  difference  the l e v e l s  ( P ^ O . 0 1 ) between each  i n ascending  Pacific  alfalfa  (45.0 ± 0.87%) had s i g n i f i c a n t l y  varieties. either  (44.9 ± 0.87%) and A l t a s w e d e  (49.1 ± 0.87%), There  was  of the red clover  order being  0.91%),  than P a c e r  Over a l l y e a r s t h e r e  Lakeland  (48.8 ± 0.87%).  lower  significant  Peace  (P^0.05) l e v e l s  Anchor (47.9 ± 0.83) o r A n i k  no  (41.5 ±  differences  o f NDF  (50.1 ± 0.87%)  (P>0.05)  between  orchardgrass or timothy v a r i e t i e s .  There was some v a r i a t i o n i n r e d c l o v e r NDF l e v e l s from y e a r t o y e a r . In  1981, b o t h L a k e l a n d and P a c i f i c v a r i e t i e s  showed s i g n i f i c a n t l y l o w e r  ( P ^ 0 . 0 5 ) NDF l e v e l s t h a n A l t a s w e d e w h i l e i n 1982 t h e r e was no difference lower  ( P > 0 . 0 5 ) between t h e v a r i e t i e s .  (P^0.05)  i n NDF t h a n A l t a s w e d e  L a k e l a n d was  signficant  signficantly  i n 1983 and P a c i f i c l e v e l s  intermediate but not s i g n i f i c a n t l y d i f f e r e n t  (P.>0.05) from  were  either  of  the o t h e r v a r i e t i e s . As  with  alfalfas.  red clover,  t h e r e was  some y e a r  to year v a r i a t i o n  with  I n 1981 Peace i s s i g n i f i c a n t l y l o w e r (P.^0.05) than A n i k f o r  NDF w h i l e P a c e r and Anchor l e v e l were i n t e r m e d i a t e b u t n o t s i g n i f i c a n t l y different (P>0.05) NDF  levels  difference  (P>0.05)  from  Anik.  between v a r i e t i e s i n Pacer  and  There  was no s i g n i f i c a n t  difference  i n 1982 b u t t h e r e was a t r e n d t o h i g h e r Anik.  ( P > 0 . 0 5 ) between a l f a l f a  Again,  there  varieties  was  no  significant  i n 1983 a l t h o u g h  Pacer  T a b l e 3.9 L e a s t Square Means ± SEM Variety  o f N e u t r a l D e t e r g e n t F i b r e by  N e u t r a l Detergent F i b r e Levels (%) Species  Year  Variety  1981  Alfalfa Pacer Anchor Peace Anik  50.7±1.02 50.5il.02f 46.4il.l8 55.011.02  Orchardgrass Kay Chinook Sterling Sumas  55.2+1.02 54.7il.02 55.2il.02 54.811.02  Timothy Climax Timfor Salvo Toro  66.311.02 66.7il.02 65.6ll.02 63.0tl.18  Alsike Tetra  1982  cd  b  d d d  d  46.0il.07 43.910.93?° 42.410.93* . 46.3tl.07  51.112.07 49.3i2.07 46.8l2.07 48.6i2.07  68.8t0.93 63.0t0.93 65.110.93 63.3t0.93  66.4l2.07 63.3i2.07 63.3i2.07 65.012.07  b c d  b c d  f 6 f 6  6  6 6 6 6  All Years  1983  C  49.110.87 47.9i0.83f 45.010.87 50.110.87 C  a b C a b C a b C  d d d  C  63.510.83 60.310.83^ 61.210.83 61.110.83  d6  d  67.910.93^ 68.210.93^ 66.9+1.07* 68.411.07  70.4t2.07 71.4i2.07 65.012.07^ 65.712.07  68.210.83* 68.710.83 65.9t0.83 :: 66.110.91  38.6t0.93  41.2t2.39  42.2l0.87  d  d  6  6  clover  Red c l o v e r Lakeland Altaswede Pacific  46.5ll.02 36.7tl.02 50.811.02 37.7ll.l8  b  a  a  a  46.9il.3lf 45.2i0.93 48.810.93  d b C d  a b  40.4t2.07 49.912.39 ° 47.812.07 a  a b  41.5t0.91 48.810.87° 44.910.87  II SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h i n columns w i t h d i f f e r e n t s u p e r s c r i p t s a r e s i g n i f i c a n t l y different (P^0.05).  a  had s l i g h t l y h i g h e r NDF  levels.  There was no s i g n i f i c a n t d i f f e r e n c e ( P > 0 . 0 5 ) between o r c h a r d g r a s s or  timothy v a r i e t i e s  orchardgrass  i n 1981 and 1983 o r between v a r i e t i e s  (68.8 ± 0.93%) had  a  s i g n i f i c a n t l y higher  i n 1982. Kay  (P^.0.05)  NDF  l e v e l i n 1982 than e i t h e r Chinook (63.0 ± 0.93%) o r Sumas (63.3 ± 0.93) while  Sterling  different  (65.1 ±  0.93%) was  intermediate but not  significantly  ( P > 0 . 0 5 ) f r o m e i t h e r group.  Neutral  detergent  fibre  levels  in  1981  (53.3  ±  0.38%)  were  s i g n i f i c a n t l y lower ( P ^ 0 . 0 5 ) i n 1981 than i n 1982 (55.7 ± 0.40%) o r 1983 (56.6 ± 0.38%) as shown i n T a b l e  3.5.  There were s i g n i f i c a n t i n t e r a c t i o n s  (P^O.01)  f o r Type, S p e c i e s and  V a r i e t y x Year. 3.2.4  ACID DETERGENT FIBRE Table  3.10  shows  the ADF  results  by Type and S p e c i e s .  y e a r s t h e r e was no s i g n i f i c a n t d i f f e r e n c e ( P > 0 . 0 5 )  Over a l l  i n ADF l e v e l between  legumes and g r a s s e s w i t h d e t e r m i n a t i o n s of 32.9 ± 0.47% and 32.0 ± 0.46% respectively.  The r e s u l t was s i m i l a r i n 1983 b u t t h e r e was a s i g n i f i c a n t  d i f f e r e n c e between legumes and g r a s s e s i n 1981 and 1982 ( P ^ O . 0 1 ) . When t h e ADF (31.0  levels  examined by  s p e c i e s , both  ± 0.55%) and r e d c l o v e r (30.9 ± 0.56%) were  ( P ^ 0 . 0 5 ) i n ADF alsike pattern  than a l f a l f a  c l o v e r (32.3 ± with  the  alfalfa  and a l s i k e  s i g n i f i c a n t l y lower  1.10%).  exception  significantly different or  were  orchardgrass  significantly  lower  (34.6 ± 0.57%), t i m o t h y (33.1 ± 0.56%) and ADF that  levels timothy  i n 1981 was  followed a  intermediate  similar to  and  ( P ^ 0 . 0 5 ) from e i t h e r o r c h a r d g r a s s and r e d c l o v e r clover.  I n 1982 b o t h  alsike  and r e d c l o v e r were  ( P ^ 0 . 0 5 ) than a l f a l f a , orchardgrass or timothy.  1983 t h e r e were no s i g n i f i c a n t  In  d i f f e r e n c e s ( P > 0 . 0 5 ) between any of t h e  T a b l e 3.10 L e a s t Square Means ± SEM^' o f A c i d Detergent Type and S p e c i e s .  A c i d Detergent  F i b r e L e v e l s by  Fibre Levels  Year Designation  1982  1981  All Years  1983  Type Legumes Grasses  34.5±0.85  a  31.1+0.84  30.9±0.38 32 9+0 37  a  33.3±0.67 i *r> ci^ a 32.1±0.67 a  1  1  32.9±0.47a o32.0+0.46 o n * n i.e. a  Species Alfalfa Orchardgrass Timothy A l s i k e Clover Red C l o v e r  37.0+0.85 28.4±0.82  C  a  34.1±0.85 38.2±1.65 29.6±1.00  32.3±0.48? 32.9+0.45? 33.9±0.46 28.2±0.90 30.2+0.54 a  (  a  3  34.3±0.95 31.6±0.95 32.5±0.95 30.5±1.89 32.8±1.09  a a a  34.6±0.57 31.0±0.55 33.1±o.56?  a  a  32.311.10  a  30.9±0.65  II SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and d e s i g n a t i o n are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  a  species. The  ADF  significant  results  by  difference  variety (P>0.05)  P a c i f i c red c l o v e r v a r i e t i e s (34.6 no  ± 0.7%)  had  significant  ( T a b l e 3.11)  (29.4  between ± 0.8%)  over a l l y e a r s  Lakeland  (28.3  a l t h o u g h Altaswede  a s i g n i f i c a n t l y h i g h e r (P^0.05) ADF  difference  ±  level.  ( P > 0 . 0 5 ) between a l f a l f a ,  showed 0.8%)  no and  red clover There  was  orchard-grass  and  timothy v a r i e t i e s . When the v a r i e t i e s significantly  g r e a t e r ( P ^ 0 . 0 5 ) i n ADF  varieties  in  signficant  difference  red  i n 1983  clover  were examined by  1981  and  Lakeland  year Altaswede  red  clover i s  l e v e l t h a n L a k e l a n d and  varieties  in  1982.  ( P > 0 . 0 5 ) between L a k e l a n d  a l t h o u g h the A l t a s w e d e  ADF  There  . P a c i f i c and  Pacific was  no  Altaswede  l e v e l s were a t l e a s t  6.6  percentage p o i n t s h i g h e r . Alfalfa  ADF  (P>0.05).  In  levels 1982  in  Pacer  1981  had  were  not  significantly  s i g n i f i c a n t l y higher values  w h i l e b o t h Anchor and A n i k showed i n t e r m e d i a t e l e v e l s  different than  i n 1983  Peace  there  was  a g a i n no s i g n i f i c a n t d i f f e r e n c e (P>0.05) between v a r i e t i e s . There  was  orchardgrass varieties  no  significant  varieties  in  1981,  i n any y e a r except  (P.^0.05) i n ADF There was  difference 1982  t h a t i n 1983  no  significant  (P^O.Ol) .  1983  or  S a l v o was  between  between timothy  s i g n i f i c a n t l y lower  (P>0.05).  d i f f e r e n c e between y e a r s  and  Variety  ( T a b l e 3.5)  for  However, when a n a l y s e d by S p e c i e s t h e r e was  a s i g n i f i c a n t d i f f e r e n c e between y e a r s Species  and  (P>0.05)  t h a n C l i m a x , T i m f o r o r Toro v a r i e t i e s .  Type and V a r i e t y  Type,  between  x  Year  (P^O.01). interactions  were  a l l significant  T a b l e 3.11 L e a s t Square Means ± SEM Variety  o f A c i d D e t e r g e n t F i b r e L e v e l s by  A c i d Detergent F i b r e (%) Species and Variety  1981  Alfalfa Pacer Anchor Peace Anik  36.4±l.l * 36.2±l.l * 35.1±1.3 39.9±1.1  Orchardgrass Kay Chinook Sterling Sumas Timothy Climax Timfor Salvo Toro Alsike clover Tetra Red c l o v e r Lakeland Altaswede Pacific  Levels  Year 1982  All Years  1983  34.7±0.9 . 31.7±0.7 ° 30.7±0.7 33.0±0.9  36.4±1.6 , 33.6±1.6 ? 33.8±1.6 33.5±1.6  35.6±0.8 33.8±0.7° * 33.1±0.8 35.8±0.8  30.0±l.l 27.7±l.l £ 28.7+l.l ? 26.9±1.1  34.0±0.7 33.5±0.7° 32.3±0.7? 31.8±0.7  32.4±1.6 30.8±1.6 30.2±1.6 33.1±1.6 °  b cde 32.2+0.7 30.6±0.7 30.4±0.7 \ 30.6±0.7  35.0±l.l f 34.3±l.l * 34.0±l.l " 32.6±1.3  33.1±0.7 32.8±0.7 31.8±0.9 33.6±0.7  35.4±1.6 35.9±1.6 28.1±1.6 30.8+1.6  34.5+0.7 34.3±0.7 31.3±0.8 32.5±0.8  38.2±l.l  28.2±0.7  e  8  e  8  8  8  bcd  a  a  C  ef  de d  fg  26.6+1.1*° 36.5±1.1 24.5±1.3 8  a  d  b  d  abC  bcd  cd  b  a  ab ab  ab ab  Cd  bcd  bcd bcd bcd  Cd  ab  a  a  30.5±1.6  a  28.1±0.9 , 29.7±0.7 , 32.3±0.7 a  aD  bcd  ab aD  ab  ab  29.8±1.6 37.6+1.6°. 31.0±1.6  ab  ab  e  b c d e  e  a b c d  abC  a b c d  cde  32.3±0.7  Cde  b c d e  b c d e  28.3±0.8 34.6±0.7 J* 29.4+0.8  11 SEM = S t a n d a r d E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column a r e s i g n i f i c a n t l y d i f f e r e n t (P$0.05).  ,  a b c d  a  ab  3.2.5  NYLON BAG DRY MATTER DISAPPEARANCE Table  years  3.12 shows t h e NBDMD r e s u l t s by Type and S p e c i e s .  t h e r e was no s i g n i f i c a n t  between There  legumes  was a  and g r a s s e s  significant  difference  (72.3±0.71  difference  (P>0.05)  i n disappearance  v s . 72.910.73%  i n NBDMD  Over a l l  respectively).  between  types  i n 1981  ( P ^ O . O l ) w i t h v a l u e s o f 68.7 ± 1.26% and 75.8 ± 1.24% and i n 1982, w i t h figures  o f 74.8 ±  respectively.  0.64 and 71.1 ±  0.62% f o r g r a s s e s  There was no d i f f e r e n c e between Type i n 1983 ( P > 0 . 0 5 ) .  For s p e c i e s , over a l l y e a r s , both a l f a l f a (70.0  ± 0.60%) were s i g n i f i c a n t l y  (75.7  ± 0.58%),  1.17%). year.  red clover  different  (68.6 ± 0.60%) and t i m o t h y  ( P ^ 0 . 0 5 ) from  (76.1 ± 0.71) and a l s i k e  There was some v a r i a t i o n  i n results  I n 1981 a l l s p e c i e s a r e s i g n i f i c a n t l y  orchardgrass clover  showing  the highest  (75.7 ± 1.11%),  1.84) and a l f a l f a alfalfa,  and legumes  timothy  orchardgrass  c l o v e r (75.9  by s p e c i e s from different  disappearance  ±  year t o  (P^O.Ol) with  (81.7 ± 0.99%) and r e d  (69.6 ± 1.03%), a l s i k e  c l o v e r (68.7  (63.6 ± 1.03%) f o l l o w i n g i n descending  o r d e r . I n 1983  o r c h a r d g r a s s and t i m o t h y were n o t s i g n i f i c a n t l y d i f f e r e n t  each o t h e r ( P > 0 . 0 5 ) b u t were s i g n i f i c a n t l y d i f f e r e n t  ±  from  ( P ^ 0 . 0 5 ) from t h e  clovers. The  results  Altaswede matter (77.3  by v a r i e t y  within  species  f o r r e d c l o v e r show  (71.4 ± 0.08%) NBDMD was s i g n i f i c a n t l y  disappearance ± 0.84%) over  than  either  a l l years  Lakeland  lower  (P^0.05) i n d r y  (79.2 ± 0.88%)  ( T a b l e 3.13).  that  or P a c i f i c  There was no s i g n i f i c a n t  d i f f e r e n c e ( P > 0 . 0 5 ) between a l f a l f a , t i m o t h y and o r c h a r d g r a s s v a r i e t i e s . In Altaswede  1981 r e d c l o v e r  varieties  NBDMD s i g n i f i c a n t l y  lower  followed  a  similar  ( P ^ 0 . 0 5 ) than L a k e l a n d  pattern  with  and P a c i f i c  T a b l e 3.12 L e a s t Square Means ± SEM o f N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s by Type and S p e c i e s  N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s (X)  Year Designation  1981  All Years  1982  1983  74.810.64 71.110.62*  73.1±0.95 71.7±0.95  72.2±0.63 73.110.59 68.9±0.63 79.6±1.18 76.410.74°  69.9±1.23 a 7 2 . 2 t l . 2 3 ab 71.1+1.23 ab  Type Legumes Grasses  68.7±1.26 75.8+1.24  a  S a  72.3±0.72 72.9±0.73  7 0  Q + n  7  Q  a  a a  Species Alfalfa Orchardgrass Timothy A l s i k e Clover Red C l o v e r  63.6±0.95 81.710.927 69.610.95? 68.711.84 75.7±1.11 a  C  b  a  79.312.45 be 75.111.42  68.6t0.60 75.710.59 70.0t0.60 75.9+1.17^ 76.110.71  II SEM = S t a n d a r d E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and d e s i g n a t i o n are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  a  a  T a b l e 3.13 L e a s t Square Means ± SEM^' o f N y l o n Bag Dry M a t t e r D i s a p p e a r a n c d L e v e l s by V a r i e t y  N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s (%)  Species and Variety  Year 1981  1982  Alfalfa Pacer Anchor Peace Anik  63.5±1.2 65.6±1.2 66.2±1.3 59.7±1.2  Orchardgrass Kay Chinook Sterling Sumas Timothy Climax Timfor Salvo Toro Alsike clover Tetra Red c l o v e r L a k e li a n di Altaswede Pacific  All Years  1983  71.1±1.3 71.7±l.l ^ 73.3±l.l f . 72.1±1.3  67.2±1.8 69.0±1.8 ? 71.0+1.8 ? . 72.4±1.8  67.5±0.8 , 68.8+0.8 ? 70.3±0.8 ? 68.0±0.8  82.Oil.2 81.1+1.2^ 82.311.2* 81.5±1.2  72.2±l.l 71.1±l.l 72.8+l.l 75.8±l.l  72.3±1.8 69.1±1.8 , 72.4±1.8 ^ 75.1±1.8  75.5±0.8 74.0±0.8 , 75.8+0.8^ 77.5±0.8  70.7±1.2 69.7+1.2^ 67.9+1.2 70.2±1.3  70.4±l.l 69.6±l.l 67.2±1.3 67.5±1.3  66.0±1.8 65.8±1.8 76.5+1.8° 76.2+1.8  69.0±0.80 68.4±0.8 ? 70.6±0.8 ^ 70.7+0.9  68.7±1.2  79.6±l.l  b  abcd  ab  a  d  d  C  C  C  80.7±1.2 67.8+1.2^° 79.6±1.3 d  ab  b  d  d  abcd  abcd abcd  a b c d  cde  abc  aD  a a  ab  a  a  76.7±1.6 77.1±l.l ^ 75.5±l.l de  d  cde  c  abcd  a b c d  abC  ab  bcd  a  d  79.8±1.8 69.2+1.8 °° 76.4±1.8 a  a  a  cd  C  ab  d  d  d  a  a  a  79.3±1.8  e  C  a  75.9±0.8° 79.2±0.9* 71.4+0.8 77.3+0.8  11 SEM = S t a n d a r d E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column a r e s i g n i f i c a n t l y different (P^0.05).  d  varieties. (P<0.05) (66.2  Anik variety than e i t h e r  alfalfa  Pacer  ± 1.3%) v a r i e t i e s .  (59.7 ± 1.2%) was s i g n i f i c a n t l y  lower  (63.5 ± 1.2%), Anchor (65.6 ± 1.2%) o r Peace There was no s i g n i f i c a n t  difference  (P>0.05)  between o r c h a r d g r a s s and t i m o t h y v a r i e t i e s . There was no s i g n i f i c a n t  difference  (P>0.05)  timothy, orchard grass or a l f a l f a v a r i e t i e s  between r e d c l o v e r ,  i n 1982.  I n 1983 A l t a s w e d e had was s i g n i f i c a n t l y l o w e r NBDMD l e v e l s than  Lakeland  variety.  significantly different  Pacific  and L a k e l a n d  (P>0.05).  (P.^0.05)  varieties  were n o t  There was no s i g n i f i c a n t  difference  ( P > 0 . 0 5 ) between a l f a l f a and o r c h a r d g r a s s v a r i e t i e s , however, t h e r e was some v a r i a t i o n Timfor  i n timothy  varieties.  Both  Climax  (66.0  (65.8 ± 1.8%) t i m o t h y were s i g n i f i c a n t l y d i f f e r e n t  ± 1.8%)  and  ( P ^ 0 . 0 5 ) from  S a l v o (76.5 ± 1.8%) and Toro (76.2 ± 1.8%) v a r i e t i e s . Again varieties  the red clovers in a  manner  continued  consistent  t o show  with  those  differences seen  between  with  previous  determinations. T a b l e 3.14 shows t h e e f f e c t s Variety. (P>  o f y e a r on NBDMD f o r Type, S p e c i e s and  There was no s i g n i f i c a n t  0.05),  however  there  was a  difference  between Y e a r s  significant  difference  f o r Type  (P ^ 0.01)  between y e a r s f o r S p e c i e s w i t h NBDMD l e v e l s b e i n g s i g n i f i c a n t l y lower i n 1981 (P<:0.05) 0.38%  t h a n i n Y e a r s 2 o r 3 (72.0 ± 0.39, 74.3 ± 0.04 and 73.6 ±  respectively).  There was no s i g n i f i c a n t  difference  (P>-0.05)  between y e a r s f o r v a r i e t y . The 3.15. between  results Over  of the e f f e c t  a l l years  animals  of animal  on NBDMD a r e shown i n T a b l e  t h e r e was a s i g n i f i c a n t  f o r Type,  Species  and V a r i e t y .  difference  (P^O.Ol)  The r e s u l t s  of the  T a b l e 3.14 L e a s t Square Means ± SEM o f N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s by Y e a r  N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s (%) Designation Year  Type  1981 1982 1983  72.4 73.l 72.4  SEM '  0.4  1  a a a  Species  Variety  72. Of 74.3 73.6  72.3 72.8 72.4  b  b  0.4  a a a  0.4  II SEM=Standard E r r o r of t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  T a b l e 3.15 L e a s t Square Means ± SEM o f N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l by A n i m a l  N y l o n Bag Dry M a t t e r D i s a p p e a r a n c e L e v e l s (%)  Year Designation  Animal  1981  1982  1981 1982  72.9±0.33 71.7±0.33  1981 1982  73.0±0.35 70.8±0.35  1981 1982  72.9±0.3 71.7±0.3  All Years  1983  Type b a  73.2±0.38 72.8±0.38  a a  73.1±0.33 71.7±0.33  b a  73.1±0.34 72.1±0.34  b a  Species b a  74.9±0.31 73.2±0.31  b a  74.2±0.36 72.9±0.36  b a  74.2±0.32 72.4±0.32  Variety b a  73.0±0.3 72.6±0.3  a a  73.1±0.3 71.7±0.3  b a  73.0±0.2 72.0±0.2  1f SEM = S t a n d a r d E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and d e s i g n a t i o n are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  b a  b a  effect  of  animal  upon  NBDMD  by  year  show  there  was  a  significant  d i f f e r e n c e ( P ^ O . 0 1 ) between a n i m a l s f o r Type, S p e c i e s and V a r i e t i e s 1981  and  1983.  There was  no  significant  difference  (P>0.05)  for  between  a n i m a l s f o r 1982. The  Type  x  Animal  interaction  ( P ^ O . 0 1 ) but not i n 1983 Species x Animal  was  in  ( P > 0 . 0 5 ) or over a l l Y e a r s  interactions  were s i g n i f i c a n t  The V a r i e t y x A n i m a l i n t e r a c t i o n was  1981 (P  and  1982  0.05).  The  (P^O.01) f o r a l l Years.  s i g n i f i c a n t ( P ^ O . O l ) over a l l Y e a r s  and f o r 1981 and 1982 but not f o r 1983 The  significant  (P>0.05).  Type, S p e c i e s and V a r i e t y x Year  interactions  were  significant  ( P ^ O . 0 1 ) over a l l Y e a r s  and w i t h i n Y e a r s , however, the Y e a r  interactions  Species  for  Type,  and  Variety  were  x  Animal  not  significant  were  significant  ( P ^ O . 0 1 ) but t h e V a r i e t y x Y e a r x A n i m a l i n t e r a c t i o n was not  significant  ( P > 0 . 0 5 ) . i n any of t h e c a s e s . The  Type and  S p e c i e s x Year x A n i m a l  interactions  (P>0.05) . 3.2.6  ASSESSMENT OF THE The  results  w i t h t h e DMI  of  and DDM  FEEDING VALUE  the  FVI  calculation  are  shown i n T a b l e  v a l u e s upon w h i c h they a r e based.  3.16  Timothy v a r i e t i e s  have the l o w e s t i n d e x w i t h o r c h a r d g r a s s v a r i e t i e s h a v i n g the n e x t index. the  along  lowest  Both a l f a l f a and c l o v e r had a h i g h e r i n d e x t h a n the g r a s s e s w i t h  alfalfas  having  generally  e x p e c t e d , the l a r g e s t  variation  clover varieties variation  w i t h a range  lower  values  than  the  clovers.  As  i n i n d e x v a l u e s o c c u r e d between the r e d of 7 index p o i n t s .  There was  also  some  between a l f a l f a v a r i e t i e s w i t h Peace i n d e x i n g 5 p o i n t s h i g h e r  than A n i k (53.2 v s . 48.2  index p o i n t s  respectively).  O v e r a l l P a c i f i c (57.3) and L a k e l a n d  (54.2) r e d c l o v e r v a r i e t i e s  had  TABLE 3.16 E s t i m a t i o n s o f Dry M a t t e r I n t a k e (DMI) , D i g e s t i b l e Dry M a t t e r (DDM) and F e e d i n g V a l u e Index ( F V I ) .  ESTIMATIONS Dry M a t t e r Digestible Intake- . Dry M a t t e r (gm/kg BW - ) (Z) ?t  Variety  U  FVI  1111  /:5  Alfalfa Pacer Anchor Peace Anik  77.8±0.82 79.1+0.78 81.210.57 77.011.53  63.1±0.58 64.810.67 65.5+0.49 62.611.18  49.1 51.3 53.2 48.2  Orchardgrass Kay Chinook Sterling Sumas  64.911.92 68.211.35 67.311.38 67.511.36  66.110.37 66.810.40 67.110.30 66.1+1.52  42.9 45.6 45.2 44.6  Timothy Climax Timfor Salvo Toro  60.110.76 59.510.79 62.810.55 62.810.87  64.310.61 64.510.45 66.410.58 66.110.34  38.6 38.4 41.7 41.5  83.011.34  65.011.21  54.0  84.410.95 78.6+0.76 80.911.08  67.910.22 63.810.89 67.010.38  57.3 50.1 5420  Alsike Clover Tetra Red C l o v e r Lakeland Altaswede Pacific % n  DMI = 96.4-(0.0003*CP%)-(0.0482*NDF%)-(0.0085*NDF %) (Rohweder e t a l . , 1985). DDM = 88.9-0.779*(ADF%) (Rohweder e t a l . , 1985). FVI =(DMI * DDM)/100.  the  highest  index  values  f o l l o w e d by  Peace  a l f a l f a s and, t h e n , f i f t h i n r a n k , Altaswede 3.2.7  INTEGRATION OF FORAGE QUALITY AND Over  a l l Years  significantly  and  within  (53.2)  red  and  Anchor  (51.3)  clover.  YIELD  each  Year  the  DEY  g r e a t e r ( P ^ O . 0 1 ) than t h a t of g r a s s e s  of  legumes  was  ( T a b l e 3.17).  DEY  3 levels  were  12.3  ±  When examined (P  0.01)  0.66 by  and  9.8  ±  0.64  Meals  species, orchardgrass  (7.3 ± 0.73  Meals x 10 /ha),  x  had  10 /ha the  respectively.  lowest  DEY  level  a l f a l f a l e v e l s were i n t e r m e d i a t e  3  3 (10.6  ± 0.76  M e a l s x 10 /ha)  highest levels respectively) with  DEY  timothy and  (12.4  and  ± 0.75,  13.9  across a l l years.  results  f o r 1981  l e v e l s were not  orchardgrass  t i m o t h y , r e d and a l s i k e c l o v e r s ± 0.87  and  There was  the  same as  14.2  in  1983  Meals x  the  10 /ha 3  l i t t l e v a r i a t i o n between y e a r s those  f o r a l l Years.  significantly different  while  ± 1.47  had  alfalfa,  In  (P<:0.05) from  timothy  and  red  1982  alfalfa  clover  and  o r c h a r d g r a s s and a l s i k e c l o v e r were not s i g n i f i c a n t l y d i f f e r e n t . For  Varieties  within  difference  (P ^ 0 . 0 5 )  varieties.  T h i s was  some  variation  over  also  in levels  significantly  h i g h e r DEY  years  when  Anik  levels  ± 0.33,  were a l s o s i g n i f i c a n t  3.18)  i n DEY  alfalfa  than  6.9  ± 0.33  the was  and  only  red  clover  However, t h e r e  significantly  Toro t i m o t h y  ( P ^ O . 0 1 ) i n DEY  and 15.6  ± 0.32  Variety  was  higher  C l i m a x and T i m f o r a l s o  S a l v o and  Type, S p e c i e s and  significant  between  1982. had  than Anchor and Peace.  respectively.  Similar  a l l years  a significant difference  w i t h l e v e l s o f 12.6 all  (Table  the case i n 1981  1983  ( P ^ 0 . 0 5 ) DEY  There was  species  had  varieties.  between Y e a r s  Meals x 10 /ha f o r 3  x Year  interactions  (P^!0.01).  t o the case  f o r DEY,  CPY  l e v e l s were s i g n i f i c a n t l y g r e a t e r  ( P ^ O . 0 1 ) f o r legumes than g r a s s e s over a l l y e a r s (0.64 ± 0.26  and 0.34  ±  T a b l e 3.17 L e a s t Square Means ± SEM ' o f D i g e s t i b l e Energy Y i e l d s by Type and S p e c i e s 1  D i g e s t i b l e Energy Y i e l d s (Meals x 10 /ha) 3  Year Designation  All Years  1981  1982  1983  12.0±1.04 11.3+1.03 a  7.8±0.56 4.2±0.54  b 17.2±0.76 14.1±0.75  12.3±0.66 9.8±0.64  8.9±1.07 7.0±1.04 15.9+1.07? 18.1+2.077 14.1±1.25  5.3±0.65 3.6±0.61 4.8±0.65 10.9±1.217 9.9+0.77  18.1+0.92° 11.2±0.92 17.0±0.92 ° 13.7+1.83 17.4±1.10°  10.6±0.76 7.3±0.73 12.4±0.75 14.2±1.47° 13.9±0.87°  Type Legumes Grasses  J  J  Species Alfalfa Orchardgrass Timothy A l s i k e Clover Red C l o v e r  a  a  a  a  a  a  b  11 SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and d e s i g n a t i o n are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  a  T a b l e 3.18 L e a s t Square Means 1 SEM Variety  o f D i g e s t i b l e Energy Y i e l d s by  D i g e s t i b l e Energy Y i e l d (Meals x 10 /ha) 3  Species and Variety  Year 1981  1982  Alfalfa Pacer Anchor Peace Anik  8.611.26? 7.911.26? 9.7il.45?° 9.611.26  5.2ll.05 4.7t0.91 ? 5.2l0.91 6.4tl.05  Orchardgrass Kay Chinook Sterling Sumas  8.2±1.26 6.811.26*7 6.0il.26 ? 6.9ll.26  4.6l0.91 3.1t0.91 3.910.91 2.8t0.91  Timothy Climax Timfor Salvo Toro Alsike clover Tetra Red c l o v e r Lakeland Altaswede Pacific  b  a b  16.7il.26 16.7±1.26T 15.311.26* 14.811.45  d e  13.2il.26° 23.011.26 3.6tl.45 a  d  a  b C  a b  a  d e  18.1il.26  a b  a  a  a  5.4t0.91 5.1i0.91 ? . 4.6ll.05 ? 3.811.05 a b  e 6  All Years  1983  a  a  10.9l0.91  d  9.0ll.29 14.5l0.9l , 5.810.91  c d  e  18.111.20^ f f  16.711.20 * 16.511.20 20.811.20 s  ah  11.911.20 10.6tl.20 11.611.20 10.9ll.20  10.5l0.84 9.710.84?° 10.1+0.84°° 12.210.84 b c  8.2t0.65 6.8l0.65 7.2i0.65 6.9i0.65  a  a  ab a a a  19.8il.2oj: 20.211.20^, 14.9H.20 ° 12.911.20  14.0i0.65 14.010.65 11.610.84° 10.910.88°  13.7tl.20  14.2t0.65  g  b  d e  a b c d  17.3il.20 25.011.38 . 11.711.20  d e f g  d  d  13.5l0.88 21.010.65 6.8t0.84  1[ SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column a r e s i g n i f i c a n t l y different (P^0.05).  d 6 a  0.26  t/ha r e s p e c t i v e l y )  and w i t h i n  each y e a r ( T a b l e 3.19).  Both o r c h a r d g r a s s and t i m o t h y had s i g n i f i c a n t l y lower ( P ^ O . O l ) CPY levels  than  either  however v a r i a t i o n  alfalfa,  clover  or red clover.  There was  from y e a r t o y e a r i n CPY w i t h a l f a l f a and o r c h a r d g r a s s  having the lowest l e v e l s 1983.  alsike  i n 1981 w h i l e a l f a l f a had t h e h i g h e s t l e v e l i n  Timothy had s i g n i f i c a n t l y h i g h e r ( P ^ 0 . 0 5 ) CPY l e v e l s than  i n 1981, s i m i l a r l e v e l s i n 1982 and lower l e v e l s i n 1983. clover  y i e l d s were n o t s i g n i f i c a n t l y d i f f e r e n t  alfalfa  A l s i k e and r e d  (P >0.05) i n any Y e a r o r  over a l l Y e a r s . Again (P^0.05)  as e x p e c t e d ,  occurred both w i t h i n  no s i g n i f i c a n t d i f f e r e n c e  alfalfa,  species with  significant  i n CPY l e v e l s between v a r i e t i e s was r e d c l o v e r  These d i f f e r e n c e s is  the only  orchardgrass  ( T a b l e 3.20).  y e a r s and over a l l y e a r s .  ( P > 0 . 0 5 ) between V a r i e t i e s  o r timothy  differences  s p e c i e s over  a l l years  There  within  either  or within  each  year. CPY was s i g n i f i c a n t l y d i f f e r e n t of  0.42 ±  1.46, 0.26 ±  respectively.  3.2.8  1.54 and 0.77 ±  The Type, S p e c i e s  also s i g n i f i c a n t  (P.^0.05) between y e a r s w i t h  and V a r i e t y  1.91 t / h a f o r a l l y e a r s x Year  interactions  were  (P^O.Ol).  NBDMD RESULTS USING PLOTS OR ANIMALS AS REPLICATES The  experimental  design  used  f o r e v a l u a t i n g NBDMD l e v e l s  v a r i e t i e s i n t h i s study c a l l e d f o r s i x t e e n  d a t a were a n a l y s e d u s i n g t h e f i e l d o r d e r t o attempt variety  replicates replicates.  t o reduce  were  per variety  Thus, t h e  samples as t h e r e p l i c a t e s .  In  t h e amount o f work i n v o l v e d t h e r e s u l t s  for  mathematically was  plot  between  n y l o n bags t o be i n c u b a t e d p e r  v a r i e t y p e r y e a r (2 bags / a n i m a l x 2 a n i m a l s x 4 r e p l i c a t e s ) .  each  levels  composited  determined)  Even though d u p l i c a t e  ( t h e mean  and a n i m a l s  of the four were  used  as  d e t e r m i n a t i o n s would s t i l l be done f o r  T a b l e 3.19 L e a s t Square Means ± SEM And S p e c i e s  o f Crude P r o t e i n Y i e l d s by Type  Crude P r o t e i n Y i e l d s (t/ha) Year Designation  1981  1982  All Years  1983  Type Legumes Grasses  0.5010.40 0.37l0.41  £  0.38±0.28 0.15±0.27'  1.0410.38 0.5010.38  0.2610.33 0.1410.31 0.1610.32* 0.5510.62 0.4810.37 b  1.2010.45 0.43i0.45 0.57t0.45 0.8210.89* 0.8910.51  0.6410.26 0.3410.26  2  £  Species Alfalfa Orchardgrass Timothy A l s i k e C l o v er Red C l o v e r  0.36i0.47 0.27i0.46 0.47l0.47* 0.7710.92 0.6110.55 a  a  £  C  a  a  0.6010.35 0.28i0.34 0.39l0.35 0.7110.68* 0.6610.40  1f SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column and d e s i g n a t i o n are s i g n i f i c a n t l y d i f f e r e n t ( P ^ 0 . 0 5 ) .  a  a  T a b l e 3.20 L e a s t Square Means ± SEM  o f Crude P r o t e i n Y i e l d s by V a r i e t y  Crude P r o t e i n Y i e l d (t/ha) Species and Variety  Alfalfa Pacer Anchor Peace Anik Orchardgrass Kay Chinook Sterling Sumas Timothy Climax Timfor Salvo Toro Alsike clover Tetra Red c l o v e r Lakeland Altaswede Pacific  Year 1981  1982  0.33±0.60 J a  0.30±0.60 0.42±0.70 0.39±0.60  ah  Cde  abcd  bcde  * *  bcdef  0.25+0.57 7 0.23±0.50 * 0.26±0.50 0.33±0.57 a  a  0.28±0.60 0.2510.60 0.25±0.60 * . 0.30±0.60  0.18±0.50 0.12±0.50 0.16±0.50 0.12+0.50  0.5010.60® 0.47±0.60r~; 0.46+0.60°  0.18±0.50 0.17+0.50 0.15±0.57 0.13±0.57  0.77±0.70  0.55±0.50  abcd  abC  a  a b c d e  f  0.43±0.60 f bcd  S  0.59±0.60* 0.99+0.60 0.16+0.70 3  .  All Years  1983  a  0.45±0.74 0.37±0.74 0.44+0.74 ? 0.44±0.74  0.31±0.43 0.2510.43 0.28±0.43 * 0.29±0.43  e  0.56+0.44 * 0.58±0.44 * 0.68±0.44 6  e  e  6  e  abc  a  a  a  a  3  a  a  ab  0.64±0.74 ° 0.60+0.74 ? 0.54±0.74 ? • 0.51±0.74  0.44±0.43° 0.41±0.43 ? 0.38±0.44 0.38±0.47  0.82±0.74  0.71±0.43  b  a  a  a  a  aD  d  e  0.58±0.44 Jl  6  ab  a  0.45±0.71 0.70±0.50 0.28±0.50  1.18+0.74 1.14±0.74 1.15+0.74 1.32±0.74 •  cd  0.87±0.74 1.25+0.85® 0.63+0.74  cd  C  d  abC aDC  f  0.64±0.47 0.98±0.43 0.34+0.44  ef  d  S  DC  1[ SEM=Standard E r r o r o f t h e Mean. a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column a r e s i g n i f i c a n t l y different (P^0.05).  aDC  each v a r i e t y o n l y 4 bags p e r v a r i e t y p e r y e a r would be i n c u b a t e d t h e r e b y r e d u c i n g t h e work l o a d . Table  3.21 shows  the results  analysed using the f i e l d plot One  plots  o b t a i n e d when  as r e p l i c a t e s  data  Field  plot  replicates)  samples  there  was  a  as r e p l i c a t e s significant  1981 were  or compositing the f i e l d  samples and u s i n g t h e a n i m a l s as r e p l e c a t e s . —  from  I n b o t h cases  and Case  difference  Two —  (Case  A n i m a l s as  (P ^ 0 . 0 1 )  between  v a r i e t i e s and i n Case 1 t h e r e was a s i g n i f i c a n t d i f f e r e n c e ( P ^ 0 . 0 5 ) i n NBDMD l e v e l s between a n i m a l s . difference  and t h e s e  within  cases t h e r e was no s i g n i f i c a n t  ( P > 0 . 0 5 ) between o r c h a r d g r a s s and t i m o t h y v a r i e t i e s .  was a s i g n i f i c a n t cases  I n both  difference differences  the c l o v e r s ,  There  ( P ^ 0 . 0 5 ) between a l f a l f a v a r i e t i e s were  Tetra alsike  t h e same i n b o t h clover  cases.  within  Similarly,  i s not s i g n i f i c a n t l y  different  ( P > 0 . 0 5 ) from A l t a s w e d e r e d c l o v e r b u t b o t h were s i g n f i c a n t l y  different  i n b o t h cases ( P ^ 0 . 0 5 ) from L a k e l a n d and P a c i f i c r e d c l o v e r s . 3.2.9 WEATHER Weather d a t a f o r t h e Engen a r e a British  Columbia  Ministry  of  (Appendix  1) were s u p p l i e d by t h e  Environment.  The  temperature  and  p r e c i p i t a t i o n d a t a were from t h e Vanderhoof  s t a t i o n and t h e s u n s h i n e d a t a  were  Although  from  collected  the Fort directly  S t . James from  the s i t e  station.  Cheesman ( P e r s .  " t h e d a t a s h o u l d be r e a s o n a b l y r e p r e s e n t a t i v e " .  t h e d a t a were n o t  comm.) suggested  that  The c u m u l a t i v e hours o f  s u n s h i n e and m i l l i m e t r e s o f p r e c i p i t a t i o n f o r May and June (most o f t h e plots  were  harvested  i n June)  indicate  t h a n t h e o t h e r two y e a r s o f t h e t r i a l . h i g h e r f i g u r e f o r growing degree  that  1982 was much  T h i s was a l s o r e f l e c t e d  days f o r 1982.  drier i n the  As w e l l , t h e June mean  temperature was much h i g h e r i n 1982 t h a n i n e i t h e r 1981 o r 1982.  T a b l e 3.21 L e a s t Square Means ± SEM M a t t e r Disappearance  f o r N y l o n Bag Dry  N y l o n Bag Dry M a t t e r (%)  Disappearance  Case Variety  Case  One^'  Two  Pacer Anchor Peace Anik  63.5±1.2 65.7±1.2?° 66.1±1.4 59.7±1.2  63.7±1.0 65.7+1.0? , 66.2±1.0 ° 59.7+1.0  Kay Chinook Sterling Sumas  81. 1±1.4^ 80.5±1.2 82.3+1.2*: 81.5+1.2  82.1+1.0* 80.5+1.0* 82.3+1.0; 81.5+1.0  Climax Timfor Salvo Toro  70.7±1.2 69.7±1.2 68.5±1.2 70.4+1.4°  70.7±1.0 69.7±1.0°^ 68.5±1.0° 70.4±1.0  Tetra Lakeland Altaswede Pacific  68.7+1.2° 80.7±1.2 67.8±1.2j 79.7±1.4  68.7±1.0° 80.711.0  b  a  d  C  b  c  b  d  a  e  C  C  d  c  67  8+1  n  e  de  e  79.7+1.0*  11 SEM = S t a n d a r d E r r o r o f t h e Mean ^111 Case One = F i e l d p l o t samples used as r e p l i c a t e s (16 b a g s / v a r i e t y ) . Case Two = F i e l d p l o t samples m a t h e m a t i c a l l y composited A n i m a l s used as r e p l i c a t e s . a,b Means w i t h d i f f e r e n t s u p e r s c r i p t s i n each column a r e significantly different (P^0.05).  3.3 3.3.1  DISCUSSION  YIELD The r e s u l t s i n t h i s study showed t h a t legumes o u t - y i e l d e d g r a s s e s i n  2 of  3 Years.  (1972)  Similar  for alfalfa  and  results  have been r e p o r t e d by  bromegrass but  r e s u l t s i n w h i c h C l i m a x t i m o t h y produced clover  at McBride,  British  Columbia.  Tingle  McElgunn e t a l .  (1975) a c h i e v e d  opposite  h i g h e r y i e l d s t h a n Altaswede I n the present  study  the  red  higher  legume y i e l d was m a i n l y due t o the h i g h p r o d u c t i o n l e v e l o f Altaswede clover.  Otherwise  r e s u l t s would be  red  s i m i l a r t o t h o s e r e p o r t e d by T i n g l e  (1975). In and  the  both  same study  grasses  (Tingle,  1975)  out-yielded a l f a l f a  timothy  o u t - y i e l d e d orchardgrass  and  clover.  red  At  Engen,  the  r e s u l t s were s i m i l a r i n t h a t t i m o t h y o u t - y i e l d e d a l f a l f a but d i f f e r e n t i n that  both  c l o v e r and  Fairbourne  alfalfa  produced  (1983) r e p o r t e d y i e l d s  more f o r a g e  than  orchardgrass.  o f o r c h a r d g r a s s grown under  irrigated  c o n d i t i o n s t h a t were s l i g h t l y h i g h e r t h a n under the d r y l a n d c o n d i t i o n s a t Engen  (3.3  vs.  2.65  good c o n d i t i o n s , may according  t/ha.).  I t appears t h a t o r c h a r d g r a s s , even under  not be h i g h y i e l d i n g .  to Fairbourne  (1983) was  Another  f a c t o r of  w i n t e r weather w h i c h  importance  stressed plants  r e s u l t i n g i n c o n s i d e r a b l e v a r i a t i o n i n y i e l d even though the o r c h a r d g r a s s p l a n t s were i r r i g a t e d . Taylor  (1976)  orchardgrass  compared  varieties  and  the  yields  obtained  of  yields  Sumas, of  9.0,  r e s p e c t i v e l y i n a t e s t a t A g a s s i z , B r i t i s h Columbia. to assess Fraser Engen.  the Sumas v a r i e t y ,  Valley  and  T h i s was  the  yields  a mid  Sterling 8.8  and  than  7.7  T h i s study was  season v a r i e t y adapted  were much h i g h e r  and  those  t o the  Kay t/ha done lower  obtained  at  f u r t h e r i n d i c a t e d by the y i e l d s o b t a i n e d by C h i l d e r s e t  al.  (1978) f o r Chinook, Kay and S t e r l i n g v a r i e t i e s  respectively)  at Lethbridge, Alberta.  The c l i m a t e a t Engen would be  c l o s e r t o t h a t a t L e t h b r i d g e than a t A g a s s i z though  Chinook  orchardgrass  was  (3.3,3.0 and 2.6 t / h a  described  (Sanderson, as a w i n t e r  1985) and even hardy  variety  y i e l d s a t e i t h e r s i t e d i d n o t approach  those a t A g a s s i z .  t h a t o r c h a r d g r a s s i s n o t w e l l adapted  t o t h e Engen s i t e when compared t o  the  yields  orchardgrass  of  timothy,  may  be  alfalfa  suited  and  clover  I t would appear  varieties.  t o g r a z i n g as a p a s t u r e  crop  However, where i t ' s  l e a f i n e s s would a s s i s t i n p a s t u r e management programs. Lawrence and Warder (1979) r e p o r t e d average y i e l d s o v e r 4 y e a r s f o r C l i m a x t i m o t h y grown under i r r i g a t e d c o n d i t i o n s o f 7.7 t / h a .  These were  h i g h e r than t h e o v e r a l l y i e l d s f o r a l l t h e v a r i e t i e s t e s t e d i n t h i s although Climax  and T i m f o r produced  t h e Engen r e s u l t s ,  similar  t h e r e was l i t t l e  l e v e l s i n 1983.  difference  trial  Similar to  i n y i e l d s between  Salvo  and C l i m a x v a r i e t i e s a t t h r e e s i t e s i n O n t a r i o (5.9 and 5.0, 9.3 and 8.9, and  6.5  and  6.2  t/ha. f o r Salvo  and C l i m a x  a t Ottawa,  Guelph and  Ridgetown r e s p e c t i v e l y ) even though t h e a b s o l u t e y i e l d s v a r i e d and S u i t o r , 1981).  (Childers  These r e s u l t s suggest  that timothy i s w e l l s u i t e d to  were  d i f f e r e n c e s between  the Engen a r e a . Overall  there  no  significant  w i t h i n species of orchardgrass, timothy or a l f a l f a .  Only  were t h e r e s i g n i f i c a n t d i f f e r e n c e s between v a r i e t i e s .  varieties  i n the clovers  These d i f f e r e n c e s  i n y i e l d o f t h e c l o v e r s may i n p a r t be e x p l a i n e d by t h e v a r i a t i o n s i n t h e environment reported  they  were  originally  t h a t most r e d c l o v e r v a r i e t i e s  climatically Lakeland  f o r which  different  variety  was  from  where  developed  developed.  are not w e l l  the v a r i e t y  i n Wisconsin  was  Taylor adapted  to areas  developed.  f o r Wisconsin  (1976)  The  conditions  3.3.2 QUALITY DETERMINATIONS The r e s u l t s f o r crude p r o t e i n  from t h i s t r i a l  a r e s i m i l a r t o those  of M e r t e n s ( 1 9 8 6 ) , Theander and Aman (1986) and R o l l e r e t a l . (1978) who all  r e p o r t e d t h a t legumes had h i g h e r crude p r o t e i n  l e v e l s than g r a s s e s .  F o r example, Theander and Aman (1986) r e p o r t e d CP l e v e l s f o r g r a s s e s and legumes o f 14.4 and 8.1% r e s p e c t i v e l y ;  s i m i l a r t o 13.7% f o r legumes and  9.8% f o r g r a s s e s o b t a i n e d i n t h i s s t u d y . I n r e l a t i o n t o s p e c i e s , M e r t e n s (1986) r e p o r t e d v a l u e s o f 23.4% f o r early  v e g e t a t i v e stage  difference  alfalfa  between a l f a l f a  hay and 14.9% f o r r e d c l o v e r  and c l o v e r s  hay.  The  i n t h i s study was n o t n e a r l y as  l a r g e w i t h l e v e l s o f 14.0 and 13.2% r e s p e c t i v e l y .  S i m i l a r to the r e s u l t s  i n t h i s s t u d y McQueen (1986) and Aman and L i n d g r e n (1983) o b t a i n e d h i g h e r CP l e v e l s i n o r c h a r d g r a s s than i n t i m o t h y a t an e a r l y  s t a g e o f growth.  There appear t o be few r e f e r e n c e s i n t h e l i t e r a t u r e t o d i f f e r e n t CP levels  between  difference (12.8%)  varieties  of  a  forage  species.  There  was  little  i n CP l e v e l s between S a l v o ( 1 0 . 8 % ) , T i m f o r (11.9%) and C l i m a x  varieties  reported  by McQueen  (1986).  Similar  results  were  o b t a i n e d i n t h i s t r i a l w i t h no s i g n i f i c a n t d i f f e r e n c e between any a l f a l f a or  clover  variety  and o n l y  one o r c h a r d g r a s s  variety  (Sumas) over a l l  years. There was however, years.  Since  the lowest  a significant difference  i n CP l e v e l  between  l e v e l was i n 1981 and t h e h i g h e s t i n 1983,  weather does n o t appear t o be t h e main f a c t o r .  The CP l e v e l i n g r a s s e s  i s h i g h e r i n 1982 and 1983 than i n 1981 and i n c r e a s e d o v e r each y e a r i n legumes. The Variety clovers  significant  interactions  between  Year  and Type,  S p e c i e s and  may be e x p l a i n e d by t h e change i n t h e CP l e v e l o f a l f a l f a s and from  1981 t o 1983.  I n the f i r s t  year  the clovers  and two  o r c h a r d g r a s s v a r i e t i e s had h i g h e r CP l e v e l s than t h e a l f a l f a s . the than  levels  had changed  orchardgrass.  so b o t h  I n 1982  s p e c i e s o f legume had h i g h e r CP l e v e l s  1983 c o n t r a s t e d  with  1981 i n t h a t  the a l f a l f a  v a r i e t i e s had h i g h e r CP l e v e l s t h a n t h e c l o v e r v a r i e t i e s . Few  literature  values  Theander and Aman (1980), NDF l e v e l s further  and R o l l e r  i n legumes than  to this  are available  Mertens  (1986) ,  et_ a l . (1978) each r e p o r t e d  i n grasses.  generalization.  f o r NDF.  Mertens  The r e s u l t s  of t h i s  lower  study add  (1986) r e p o r t e d NDF v a l u e s o f  50% and 56% f o r a l f a l f a and r e d c l o v e r hays r e s p e c t i v e l y w h i l e R o l l e r e t al.  (1978)  obtained  values  timothy r e s p e c t i v e l y .  o f 67.5% and 75.7% f o r o r c h a r d g r a s s  Aman and L i n d g r e n (1983) a l s o r e p o r t e d h i g h e r NDF  v a l u e s f o r o r c h a r d g r a s s than t i m o t h y (57.9 v s . 62.7%). enough t o have a s i g n i f i c a n t impact of t h i s s t u d y . than  those  and  These l e v e l s v a r y  on i n t a k e and agree w i t h t h e r e s u l t s  The NDF v a l u e s o b t a i n e d from t h e Engen samples a r e lower  reported  by Mertens  (1986)  due t o t h e more mature  plant  m a t e r i a l w h i c h he t e s t e d . Overall,  t h e r e was l i t t l e  and o r c h a r d g r a s s v a r i e t i e s . other v a r i e t i e s  d i f f e r e n c e i n NDF v a l u e s between  Peace a l f a l f a had lower NDF l e v e l s than t h e  and each o f t h e r e d c l o v e r s had d i f f e r e n t NDF  These d i f f e r e n c e s may be due t o v a r i a t i o n s each  climate  timothy  or the p h y s i o l o g i c a l  levels.  i n t h e s t r a i n developed f o r  requirement  f o r increased  fibrous  m a t e r i a l i n t h e p l a n t stem as y i e l d s i n c r e a s e d . No d a t a on t h e v a r i a t i o n o f NDF l e v e l s over y e a r s was found literature. (55.7±0.4%)  While  1981 l e v e l s  (53.5±0.4%) were lower  o r 1983 (56.6±0.4%)  v a r i e t i e s was a p p a r e n t .  no  overall  trend  than e i t h e r 1982  within  The o t h e r f i b r e based parameters  i n the  species or  (ADF and NBDMD)  do n o t v a r y between y e a r s and o n l y t h e 1981 NDF l e v e l was s i g n i f i c a n t l y  o r c h a r d g r a s s v a r i e t i e s had h i g h e r CP l e v e l s t h a n t h e a l f a l f a s . the than  levels  had changed  orchardgrass.  so b o t h  I n 1982  s p e c i e s o f legume had h i g h e r CP l e v e l s  1983 c o n t r a s t e d  with  1981 i n t h a t  the a l f a l f a  v a r i e t i e s had h i g h e r CP l e v e l s t h a n t h e c l o v e r v a r i e t i e s . Few  literature  values  are available  Theander and Aman (1980), and R o l l e r NDF l e v e l s further  i n legumes than  to this  Mertens  (1986),  e t a l . (1978) each r e p o r t e d  i n grasses.  generalization.  f o r NDF.  Mertens  The r e s u l t s  of t h i s  lower  study add  (1986) r e p o r t e d NDF v a l u e s o f  50% and 56% f o r a l f a l f a and r e d c l o v e r hays r e s p e c t i v e l y w h i l e R o l l e r e t al.  (1978)  obtained  values  timothy r e s p e c t i v e l y .  o f 67.5% and 75.7% f o r o r c h a r d g r a s s  Aman and L i n d g r e n (1983) a l s o r e p o r t e d h i g h e r NDF  v a l u e s f o r o r c h a r d g r a s s t h a n t i m o t h y (57.9 v s . 62.7%). enough t o have a s i g n i f i c a n t impact of t h i s study. than  those  and  These l e v e l s v a r y  on i n t a k e and agree w i t h t h e r e s u l t s  The NDF v a l u e s o b t a i n e d from t h e Engen samples a r e lower  reported  by Mertens  (1986)  due t o t h e more mature  plant  m a t e r i a l w h i c h he t e s t e d . Overall,  t h e r e was l i t t l e  and o r c h a r d g r a s s v a r i e t i e s . other v a r i e t i e s  d i f f e r e n c e i n NDF v a l u e s between  Peace a l f a l f a had lower NDF l e v e l s t h a n t h e  and each o f t h e r e d c l o v e r s had d i f f e r e n t NDF  These d i f f e r e n c e s may be due t o v a r i a t i o n s each  climate  timothy  or the p h y s i o l o g i c a l  levels.  i n t h e s t r a i n developed f o r  requirement  f o r increased  fibrous  m a t e r i a l i n t h e p l a n t stem as y i e l d s i n c r e a s e d . No d a t a on t h e v a r i a t i o n o f NDF l e v e l s over y e a r s was found i n t h e literature. (55.7±0.4%)  While  1981 l e v e l s  (53.5±0.4%) were lower  o r 1983 (56.6±0.4%)  v a r i e t i e s was a p p a r e n t .  no  overall  trend  than e i t h e r 1982  within  The o t h e r f i b r e based parameters  species or  (ADF and NBDMD)  do n o t v a r y between y e a r s and o n l y t h e 1981 NDF l e v e l was s i g n i f i c a n t l y  different. The  interaction  between Y e a r and V a r i e t y ,  S p e c i e s , C l a s s and Type  was a r e s u l t o f changes i n NDF l e v e l s o f one s p e c i e s r e l a t i v e t o a n o t h e r over  the test  period.  I n 1981 t h e a l f a l f a  varieties  had NDF  levels  s i m i l a r t o o r c h a r d g r a s s w h i l e i n 1982 and 1983 t h e a l f a l f a s had h i g h e r v a l u e s than o r c h a r d g r a s s . Unlike greatly reported  NDF  levels,  ADF l e v e l s  between  legumes  and g r a s s e s .  similar  levels  between  i n the t e s t Theander  grasses  forages  d i d not vary  and Aman  and legumes  (1980) a l s o  (31.3 v s  32.4%).  However, c a r e must be t a k e n when i n t e r p r e t i n g ADF v a l u e s between  grasses  and legumes due t o t h e e f f e c t o f p h e n o l o g i c a l s t a g e . At t h e s p e c i e s l e v e l b o t h r e d c l o v e r and o r c h a r d g r a s s were lower i n ADF than a l s i k e also  reported  clover,  slightly  timothy lower  and a l f a l f a .  ADF v a l u e s  Aman and L i n d g r e n  f o r orchardgrass  than  (1983) timothy  (32.6 and 34.1%) c u t a t t h e same growth s t a g e . W i t h t h e e x c e p t i o n o f t h e r e d c l o v e r s t h e r e was no d i f f e r e n c e i n ADF l e v e l s between v a r i e t i e s . results  to this  (38.1%) t i m o t h y levels the  study  with  varieties  the v a r i a t i o n  result  W i t h i n s p e c i e s McQueen (1986) o b t a i n e d s i m i l a r Salvo  harvested  (36.3%), near  o f t h e need  f o r additional  the extra plant  variety  o r may be due t o v a r i a t i o n  species,  however  interactions  the boot stage.  difference there  w i t h Year.  fibrous  Climax  As w i t h NDF  m a t e r i a l to p h y s i c a l l y  material f o r the higher  were  producing  i n red clover strains  v a r i a t i o n i n c l i m a t e s f o r w h i c h they were was no  (36.5%) and  i n ADF v a l u e s between r e d c l o v e r v a r i e t i e s may be  support  There  Timfor  Altaswede due t o t h e  developed.  i n ADF v a l u e s significant  between  Type,  years  Species  over a l l  and  Variety  T h i s r e s u l t o c c u r r e d because g r a s s e s had h i g h e r  ADF  levels  temperatures  than  legumes  affecting  y e a r s legumes tended  i n 1982, p o s s i b l y  Roller  NBDMD l e v e l s  result  f i b r e production w i t h i n the p l a n t .  e_t a l . (1978) o b t a i n e d  o f 88.8±1.0% f o r a l f a l f a ,  the higher  I n the other  d i d n o t v a r y between g r a s s e s and somewhat d i f f e r e n t  NBDMD l e v e l s  results  with  71.7±1.2% f o r o r c h a r d g r a s s and  52.2+2.0% f o r t i m o t h y f o r a 24 hour i n c u b a t i o n p e r i o d . to  of higher  t o have h i g h e r ADF v a l u e s than g r a s s e s .  As w i t h ADF l e v e l s , NBDMD v a l u e s legumes.  as a  Thus, i n a d d i t i o n  f o r a l f a l f a s r a t h e r than  g r a s s e s , he a l s o  o b t a i n e d much more v a r i e d r e s u l t s between these s p e c i e s than was o b t a i n e d with  t h e Engen  orchardgrass  samples.  In this  (75.7±0.59%) ,  study,  and  t h e c l o v e r s (76.1±0.71%) and  timothy  (68.6±0.60%) had l e s s v a r i e d d i s a p p e a r a n c e  (70.0±0.60%)  Climax  and T i m f o r  timothy  alfalfa  values.  Seone e t a d . (1981b) r e p o r t e d NBDMD v a l u e s Toro,  and  varieties  (24 hour i n c u b a t i o n ) f o r  o f 45.4, 35.7 and  38.0%  respectively.  McQueen (1986), a l s o u s i n g a 24 hour i n c u b a t i o n r e p o r t e d  NBDMD  f o r Toro  values  respectively.  These  and C l i m a x  levels  timothy  varieties  a r e c o n s i d e r a b l y lower  o f 40 and 45%  than  those  values  o b t a i n e d i n t h i s study and may be e x p l a i n e d i n t h e case o f McQueen by t h e more mature samples used r e s u l t i n g —  i n h i g h e r ADF l e v e l s  (Toro and C l i m a x  44.3 and 47.5% compared w i t h ADF l e v e l s o f 32.5 and 34.5 o b t a i n e d i n  this  study)  and lower NBDMD.  I n t h e case o f Seone e_t a l . (1981b) bags  w i t h a much s m a l l e r pore s i z e  (5 u v s . 40 u pore s i z e f o r bags used i n  t h i s study) i n t h e i r experiment  would r e s u l t i n much lower NBDMD l e v e l s .  As w i t h NDF and ADF d e t e r m i n a t i o n s t h e r e was no d i f f e r e n c e i n NBDMD v a l u e s between v a r i e t i e s w i t h i n s p e c i e s except  f o r the red clovers.  e x p e c t e d , A l t a s w e d e v a r i e t y had t h e l o w e s t d i s a p p e a r a n c e with  the higher  NDF and ADF l e v e l s  relative  As  l e v e l i n keeping  to the other  red clover  varieties. NBDMD  There was a s i g n i f i c a n t d i f f e r e n c e  results  differences  f o r a l l designations.  i n DMI  E x p e r i m e n t a l Farm. herd  average  relative  between t e s t  This  t o the other  may  have  yearling  animal f o r  been  due t o  steers  on t h e  One a n i m a l had a much lower DM i n t a k e r e l a t i v e t o t h e  (D. Croy,  Pers.  Comm.).  There  was  no  significant  i n t e r a c t i o n between Y e a r and A n i m a l . There was no s i g n i f i c a n t v a r i a t i o n Type and V a r i e t y . possibly  i n NBDMD l e v e l s due t o y e a r f o r  There was a d i f f e r e n c e  t o the v a r i a t i o n  i n alsike  between y e a r s f o r S p e c i e s due  clover  l e v e l s which  were lower i n  d i s a p p e a r a n c e i n 1981 t h a n o r c h a r d g r a s s and t i m o t h y b u t had h i g h e r l e v e l s t h a n e i t h e r i n 1982 and 1983. There was an i n t e r a c t i o n between Year and Type, S p e c i e s and V a r i e t y . The  Type x Y e a r  value  interaction  was due t o g r a s s e s h a v i n g  i n 1981 (75.8±1.24 v s . 68.7±1.26% r e s p e c t i v e l y )  a h i g h e r NBDMD and t h e legumes  h a v i n g a h i g h e r v a l u e i n 1982 (74.8±0.64 v s 71.1±0.62% r e s p e c t i v e l y ) .  In  y e a r 3 NBDMD l e v e l s were s i m i l a r f o r g r a s s e s and legumes (71.1±0.95 and 73.1±0.95 r e s p e c t i v e l y ) . by Year  T h i s would a l s o e x p l a i n  interactions.  The  i n t e r a c t i o n between Type, S p e c i e s and V a r i e t y  statistically since Animal  significant) 1 always  does  n o t appear  the r e l a t i v e difference  incubated  i n Animal  f o r Type).  i n disappearance  1 and A n i m a l  and A n i m a l  t o be o f g r e a t  showed g r e a t e r d i s a p p e a r a n c e  (73.1±0.34 v s . 72.1±0.34% r e s p e c t i v e l y in  t h e S p e c i e s and V a r i e t y  levels  (while  importance  than A n i m a l 2  The o n l y v a r i a t i o n was  l e v e l s between t h o s e samples  2 f o r samples c o l l e c t e d  i n different  years. The the  variation  i n NBDMD l e v e l s  3 study y e a r s may a l s o  explain  o f g r a s s e s r e l a t i v e t o legumes  over  t h e s i g n i f i c a n t Type and S p e c i e s x  Animal x Year i n t e r a c t i o n s . not  The V a r i e t y x A n i m a l x Y e a r i n t e r a c t i o n i s  significant.  3.3.3  ASSESSMENT OF FORAGE QUALITY Crude p r o t e i n was a p o s i t i v e i n d i c a t o r o f f o r a g e q u a l i t y w h i l e NDF  was  inversely  digestibility one  related  to  intake,  ADF  was  inversely  to  (Van S o e s t , 1982) and NBDMD r e f l e c t s t h e d i g e s t i b i l i t i e s o f  forage r e l a t i v e t o another  ( A e r t s e_t a l . , 1977).  ADF and NBDMD d e t e r m i n a t i o n s c a r r i e d out i n t h i s t r i a l of  related  one f o r a g e  relative  t o another  should  be  U s i n g t h e CP, NDF, the feeding value  estimated  with  some  reliability. In  c o n s i d e r i n g t h e r e l a t i v e f o r a g e q u a l i t y o f legumes compared w i t h  g r a s s e s NDF and CP l e v e l s become i m p o r t a n t because o v e r a l l t h e r e was no difference  between  t h e two t y p e s  f o r NBDMD  o r ADF d e t e r m i n a t i o n s .  T h e r e f o r e , i t can be assumed t h a t o v e r a l l d i g e s t i b i l i t i e s w i l l be s i m i l a r for  t h e Engen samples.  grasses  and t h i s  fact,  However, DMI w i l l coupled  legumes w i l l be n u t r i t i o n a l l y study.  This  with  be g r e a t e r f o r legumes  higher  CP l e v e l s ,  indicate  than that  superior t o the grasses evaluated i n t h i s  c o n c l u s i o n was reached  since the animal w i l l  o b t a i n more  d i g e s t i b l e n u t r i e n t s from t h e legumes t h a n from t h e g r a s s e s and f o l l o w s reports  i n the l i t e r a t u r e  t h a t i n t a k e o f legumes was g e n e r a l l y g r e a t e r  t h a n g r a s s e s o f t h e same d i g e s t i b i l i t y In  (Minson, 1982).  terms o f s p e c i e s NBDMD and ADF v a l u e s i n d i c a t e t h a t o r c h a r d g r a s s  was more d i g e s t i b l e than t i m o t h y and t h a t t h e c l o v e r s a r e more d i g e s t i b l e than a l f a l f a .  NDF v a l u e s i n d i c a t e  t h a t o r c h a r d g r a s s would be consumed  more r e a d i l y than t h e t i m o t h y and t h e c l o v e r s more r e a d i l y than a l f a l f a . In  a d d i t i o n , CP l e v e l s f o r o r c h a r d g r a s s were h i g h e r than f o r t i m o t h y so  t h a t i t may be c o n c l u d e d  t h a t o r c h a r d g r a s s was n u t r i t i o n a l l y  superior to  timothy the  i n t h i s study.  clovers  superior  quality  timothy  to a l f a l f a .  because  and a l f a l f a  descending  had a h i g h e r CP l e v e l  (14.0 v s . 13.3) i t c a n be  nutritionally better  Even though a l f a l f a  order  they  Orchardgrass  would  and would  be e a t e n  be more  of n u t r i t i o n a l  concluded  quality,  by a l f a l f a , t h e n o r c h a r d g r a s s and f i n a l l y  digestible. would  species  differences. either  the  red  S i n c e Altaswede  Lakeland  the l e a s t  only  was  were o f  amounts  than  Therefore, i n  be c l o v e r s ,  followed  timothy.  clover  factors  between v a r i e t i e s  varieties  show  significant  had lower NBDMD and h i g h e r ADF v a l u e s than  or Pacific varieties  digestible  clover  and c l o v e r  i n greater  When c o n s i d e r i n g i n t a k e and d i g e s t i b i l i t y within  that  then  red clover  i t might be c o n c l u d e d  variety.  Altaswede  i n l e s s e r amounts than t h e o t h e r two v a r i e t i e s  t h a t i t was  would a l s o be e a t e n  (as e v i d e n c e d by a h i g h e r  NDF  l e v e l ) so t h a t i n terms o f n u t r i t i o n a l q u a l i t y , even though t h e r e was  no  difference  Lakeland NDF levels  between  varieties  any o f t h e v a r i e t i e s  were  of better  nutritional quality  v a l u e s f o r Peace a l f a l f a i n d i c a t e than  the other  digestibility  alfalfa  and CP l e v e l s  i n CP l e v e l ,  P a c i f i c and  than  Altaswede.  i t would be consumed a t h i g h e r  varieties,  however,  t h e r e was no d i f f e r e n c e  i n terms  of  between any o f t h e  alfalfa varieties. NBDMD  levels  be  more  d i g e s t i b l e t h a n Chinook v a r i e t y , however, ADF l e v e l s d i d not suggest  such  a  also  difference.  suggest  Crude  protein  that  Sumas  levels  h i g h e r t h a n the o t h e r v a r i e t i e s p o i n t i n g  orchardgrass  would  f o r t h e Sumas v a r i e t y to a possible  were  difference  between  o r c h a r d g r a s s v a r i e t i e s w i t h Sumas b e i n g somewhat s u p e r i o r i n n u t r i t i o n a l quality. The  only  variation  between  timothy  varieties  f o r any o f t h e  determinations Overall  was  t h e r e was  i n CP no  level  f o r Toro w h i c h was  difference i n quality  Thus, w i t h the e x c e p t i o n of L a k e l a n d  higher  between t i m o t h y  and  Pacific  in  Therefore,  any  nutritional of  the  quality  alfalfa  orchardgrass v a r i e t i e s which,  between  varieties  i n t u r n , we  varieties.  t h a t t h e r e was  varieties  were  Timfor.  red c l o v e r s being  s u p e r i o r t o A l t a s w e d e r e d c l o v e r i t can be. concluded difference  than  within  s u p e r i o r to  s u p e r i o r t o any  no  species.  any  of t h e  of  the  timothy  varieties. Heaney  et_ al_. (1966)  i n d i c a t e d by NDF) ADF)  was  by y e a r - t o - y e a r  (1966) suggested  found  that  the  r a t e of  d e c l i n e of  a f f e c t e d more than d i g e s t i b i l i t y f l u c t u a t i o n s i n growing  that greater v a r i a b i l i t y  d i g e s t i b i l i t y o v e r a l l and e s p e c i a l l y between y e a r s . the p r e s e n t s t u d y . in  that  the  (as  (as i n d i c a t e d  conditions.  would o c c u r  DMI  by  Heaney et^ a l .  i n i n t a k e than i n T h i s i s the case i n  These a u t h o r s a l s o had s i m i l a r r e s u l t s w i t h v a r i e t i e s  differences i n  varietal  digestibilities  were  minor  and  i n the  FVI  t h a t the f e e d i n g ' v a l u e o f A l t a s w e d e r e d c l o v e r , w h i c h had  the  i n c o n s i s t e n t between y e a r s . 3.3.4  ASSESSMENT OF FEEDING VALUE Weighing  suggested  the  highest y i e l d s The  intake  of DE  c l o v e r s however,  and  and  CP,  still  digestibility  was had  lower the  results  than any  highest  of  feeding  evenly  the o t h e r value  since  i n t a k e and d i g e s t i b i l i t y were h i g h e r than f o r t h e o t h e r s p e c i e s . would be  the second b e s t  Orchardgrass  s i n c e b o t h DMI As was  and DDM  the  both  Alfalfa  s p e c i e s i n terms of f e e d i n g v a l u e s i n c e i n t a k e  would be much h i g h e r and DDM the g r a s s e s .  clovers.  was  only s l i g h t l y  lower than f o r e i t h e r of  would have a h i g h e r f e e d i n g v a l u e than  timothy  were h i g h e r f o r o r c h a r d g r a s s .  case w i t h the q u a l i t y  parameters t h e r e would be  little  difference since  for either  these  DMI  estimates  respectively.  For  the  o r DDM are  f o r the v a r i e t i e s w i t h i n each s p e c i e s  based  same r e a s o n  on  NDF  and  i t would be  ADF  determinations  expected  that  feeding  v a l u e r e s u l t s would c l o s e l y p a r a l l e l the r e s u l t s suggested by the  quality  determinations. 3.3.5  INTEGRATION OF FORAGE QUALITY AND When y i e l d  yields)  was  YIELD  i n t e g r a t e d w i t h the DE  t h e r e were some d i f e r e n c e s i n the  only q u a l i t y  parameters  a r e examined.  estimate  best and  quality  finally  I t was  concluded  The  DEY  t h a t Altaswede  red  clover,  second  results  very  i n terms  overall,  alfalfa  show t h a t one  of  then  of the  low l e v e l s of quality,  than any o t h e r s p e c i e s or v a r i e t y .  the l o w e s t q u a l i t y f o r a g e , produced  that,  f o l l o w e d by  forages, P a c i f i c red c l o v e r , y i e l d s  s u b s t a n t i a l l y more DE was  t imothy.  energy  c o n c l u s i o n s t h a t r e s u l t when  t h e c l o v e r v a r i e t i e s were the h i g h e s t q u a l i t y , o r c h a r d g r a s s and  (digestible  DE  produces  Timothy, w h i c h  e q u a l l e v e l s of DE to t h e c l o v e r s  ( e x c e p t P a c i f i c ) and s u p e r i o r l e v e l s t o b o t h a l f a l f a and o r c h a r d g r a s s . I n terms of DEY  t h e c l o v e r s and  t i m o t h y had h i g h e r l e v e l s t h a n a l f a l f a  and  o r c h a r d g r a s s had t h e l o w e s t l e v e l s . When y i e l d  was  between v a r i e t i e s C l i m a x and  taken  with  into  Salvo  Timfor v a r i e t i e s .  w h i l e Sumas and When CPY  c o n s i d e r a t i o n t h e r e was  and  timothy  Chinook o r c h a r d g r a s s produced  l e s s DE  variation  less  l e s s DE  DE  than  than A n i k  t h a n Kay  variety.  r e s u l t s were examined t h e r e were a l s o d i f f e r e n c e s i n the  Altaswede  parameters  are assessed.  As was  the  r e d c l o v e r y i e l d e d the h i g h e s t amount of CP w i t h  P a c i f i c v a r i e t y p r o d u c i n g a t much lower l e v e l s . l e v e l s of CP  producing  Anchor a l f a l f a produced  c o n c l u s i o n drawn when o n l y q u a l i t y case w i t h DEY,  Toro  some  A l f a l f a produced  similar  t o the c l o v e r s and b o t h a l f a l f a and c l o v e r had g r e a t e r  CPY  levels  than  orchardgrass  timothy  and o r c h a r d g r a s s .  i n a similar  These r e s u l t s  situation  showed t h a t ,  usable  yielded  t o t h a t which  more CP  occurred  than  w i t h DEY.  f o r t h o s e Types, S p e c i e s and V a r i e t i e s  s t u d i e d , y i e l d a l o n e was a good c r i t e r i a and v a r i e t y .  Timothy  f o r s e l e c t i n g the forage species  T h i s was due t o t h e d e s i r e t o o b t a i n t h e h i g h e s t l e v e l o f  nutrients  per hectare  of land  while  still  p h e n o l o g i c a l s t a g e t h a t p r o v i d e s optimum q u a l i t y .  harvesting  at a  The end r e s u l t was t h e  most n u t r i e n t s f o r a n i m a l p r o d u c t i o n from t h e s m a l l e s t a r e a . 3.3.6 NBDMD RESULTS USING PLOTS OR ANIMALS AS REPLICATES The  r e s u l t s o f t h i s p o r t i o n o f t h e study i n d i c a t e t h a t t h e r e was no  d i f f e r e n c e i n t h e assessment o f v a r i e t i e s and s p e c i e s when f o r a g e samples were a n a l y s e d f o r NBDMD i n e i t h e r Case 1 o r Case 2. r e s u l t s were a n a l y s e d based Case  on t h e a c t u a l  2 t h e samples were m a t h e m a t i c a l l y  field  I n Case 1 t h e NBDMD  plot  composited  by t a k i n g t h e mean  v a l u e o f t h e 4 f i e l d p l o t r e p l i c a t e s and s t a t i s t i c a l l y s i n g l e data p o i n t s . in  statistical  reduce each  significance  rather  a n a l y s i n g them as  S i n c e t h e r e was no d i f f e r e n c e between t h e two cases between v a r i e t i e s  within  t h e work l o a d t o 4 n y l o n bags p e r t r e a t m e n t animal)  samples w h i l e i n  than  t h e 16 bags  used  species  i t would  ( d u p l i c a t e samples i n  i n this  samples i n each a n i m a l f o r each f i e l d r e p l i c a t e p l o t ) .  study  (duplicate  This conclusion  appears t o be v a l i d even though fewer degrees o f freedom would r e s u l t i n the need t o o b t a i n l a r g e r F v a l u e s  i n t h e ANOVA  and l e s s p r e c i s i o n i n  means s e p a r a t i o n ( T a b l e 3.21). The  d i f f e r e n c e s i n NBDMD l e v e l s between Altaswede  and L a k e l a n d and  P a c i f i c r e d c l o v e r i n d i c a t e t h a t , even w i t h fewer o b s e r v a t i o n s , r e l i a b l e d i f f e r e n c e s would be determined.  CHAPTER 4 FEEDING TRIAL  4.1 MATERIAL AND METHODS 4.1.1  FORAGES In  order to assess  the n u t r i t i o n a l  quality  o f two f o r a g e  mixtures  h a r v e s t e d a t t h r e e d i f f e r e n t growth s t a g e s two 0.5 ha p l o t s were p l a n t e d in  the s p r i n g . of  different mixture  times  1983 w i t h  forage  i n t h e growing  mixtures  season.  intended  The e a r l i e r  t o mature maturing  at  forage  (EM) c o n s i s t e d o f T e t r a a l s i k e c l o v e r , Toro t i m o t h y and Manchar  bromegrass Altaswede  and  the l a t e r  maturing  forage  r e d c l o v e r and C l i m a x t i m o t h y .  mixture  (LM) c o n s i s t e d o f  Agronomic p r a c t i c e s were those  4  recommended  f o r the area  and c r o p .  The p l o t s  were  fertilized  with  34-0-0-11 a t t h e r a t e o f 180 kg/ha i n t h e s p r i n g p r i o r t o h a r v e s t . Each p l o t was h a r v e s t e d i n 1984 a t 10%, 50% and 100% o f legume bloom ( e a r l y bloom, EB; mid bloom, MB; f u l l harvest  dates  field-cured  and y i e l d s  and t h r e e  f o r each  bloom, F B ) .  T a b l e 4.1 shows t h e  o f t h e hay c u t s .  o f t h e s i x samples  Forages  r e c i e v e d some  were  precipitation  w h i l e b e i n g d r i e d (EM-EB,EM-FB and LM-EB). Once  cured,  transported  t h e hay  was  baled  into  small  square  bales  and  t o t h e P r i n c e George E x p e r i m e n t a l Farm where i t was s t o r e d  under c o v e r i n t h e b a r n where t h e f e e d i n g t r i a l was  conducted.  The o b j e c t i v e s o f t h e f e e d i n g t r i a l were: 1)  t o assess the e f f e c t on.animal  i n t a k e and d i g e s t i b i l i t y o f  an e a r l y and a l a t e m a t u r i n g f o r a g e m i x t u r e , and; 2)  t o a s s e s s t h e e f f e c t on a n i m a l i n t a k e and d i g e s t i b i l i t y o f harvesting  a t t h e e a r l y , mid and f u l l  bloom growth  of t h e legume component o f each f o r a g e m i x t u r e .  stages  T a b l e 4.1 H a r v e s t Date and Y i e l d o f T e s t Forages Hay M i x  H a r v e s t Date  Yield (T/ha)  Early Maturing (EM) E a r l y Bloom (EB)++ Mid Bloom (MB) F u l l Bloom (FB)  July 9 J u l y 15 J u l y 22  5.6 7.6 9.4  1111 L a t e M a t u r i n g (LM) E a r l y Bloom (EB) Mid Bloom (MB) F u l l Bloom (FB)  J u l y 22 J u l y 30 August 8  9.2 9.9 11.0  +  11  + EM = a l s i k e c l o v e r - t i m o t h y - bromegrass f o r a g e mix. ++ EB,MB,LB = 102,50% 100% o f bloom o f t h e legume component of t h e f o r a g e mix. 11 E s t i m a t e f o r EM-EB based on known w e i g h t of a i r d r y m a t e r i a l removed f r o m 0.1 ha. 1111 LM = r e d c l o v e r - t i m o t h y f o r a g e mix.  4.1.2  EXPERIMENTAL DESIGN AND STATISTICAL ANALYSIS T h i s experiment  e v a l u a t e d t h e i n t a k e and d i g e s t i b i l i t y o f two f o r a g e  mixes each c u t a t t h r e e s t a g e s o f growth. combinations.  Thus, t h e r e were s i x t r e a t m e n t  S i n c e i n t a k e and d i g e s t i b i l i t y v a r y between a n i m a l s i t was  d e s i r a b l e t o t e s t each t r e a t m e n t variability  may a r i s e  e l a p s e from  the beginning  c o m b i n a t i o n w i t h each a n i m a l .  due t o t e s t  periods  In turn,  s i n c e c o n s i d e r a b l e time  t o t h e end o f t h e e x p e r i m e n t .  may  Therefore, i n  a d d i t i o n t o t r e a t m e n t e f f e c t s t h e v a r i b i l i t y due t o a n i m a l and p e r i o d was also  accounted  combinations  for.  The i n t a k e and d i g e s t i b i l i t y  was a n a l y s e d as a 2x3 f a c t o r i a l  of the s i x treatment  experiment  i n a 6x6 L a t i n  square d e s i g n . The  f a c t o r s used i n t h e experiment 1)  2)  1982 f o r a g e s  were:  mixes;  a)  E a r l y M a t u r i n g (EM),  b)  L a t e M a t u r i n g (LM), and  Three h a r v e s t d a t e s ; a) ' 10% Bloom ( E B ) ,  The  b)  50% Bloom (MB),  c)  100% Bloom ( F B ) .  following  least  squares  model was used  to analyse a l l of the  data i n the feeding t r i a l :  Y  ijki •  u  +  A  i  +  p  j  +  \  +  H  i  +  ¥ i  +  e  ijki  where =  the dependent v a r i a b l e i n t a k e and d i g e s t i b i l i t y ,  u = t h e o v e r a l l mean common t o a l l samples  A. = t h e e f f e c t due t o t h e i ' t h a n i m a l 1  P_. = t h e e f f e c t due t o t h e j ' t h p e r i o d = t h e e f f e c t o f t h e k ' t h f o r a g e mix = the e f f e c t of the l ' t h harvest M^H^ = t h e i n t e r a c t i o n o f t h e k ' t h f o r a g e mix w i t h t h e l'th e^jj^  harvest  = the unexplained  residual error associated with  each sample. As General  i n the variety L i n e a r Models  variation  with  a n a l y s i s o f v a r i a n c e was done u s i n g t h e  (GLM) p r o c e d u r e  significant  Student-Newman-Kuels 1980).  trial  F values  multiple  (SAS, 1985). were  comparison  tested  sources of  f o r s i g n i f i c a n c e by  o f means  I n a d d i t i o n , t h e RSQUARE p r o c e d u r e  Those  (Steel  and T o r r i e ,  (SAS, 1985) was used t o  determine i f m u l t i p l e f a c t o r r e g r e s s i o n e q u a t i o n s  c o u l d be developed t o  p r e d i c t t h e above p a r a m e t e r s . 4.1.3. Six  INTAKE AND DIGESTIBILITY TRIAL METHODOLOGY wether  sheep  were  placed  i n metabolism  i n d i v i d u a l f e e d i n g and f e c a l c o l l e c t i o n . mineral  salt  and w a t e r and a l l a n i m a l s  crates  designed f o r  Each a n i m a l had a c c e s s t o t r a c e were weighed a t t h e end o f each  period. P r i o r t o f e e d i n g a l l f o r a g e s were chopped through a 2.5 cm s c r e e n i n a hammer m i l l .  The f o r a g e s were f e d t w i c e d a i l y a t 08:30 and 16:00 h .  Samples o f each chopped f o r a g e were t a k e n weekly f o r a n a l y s i s and s t o r e d in a freezer u n t i l  analysed.  Each o f t h e 6 t e s t p e r i o d s c o n s i s t e d o f 5 days f o r adjustment t o t h e new f e e d , 7 days f o r ad l i b i t u m f e e d i n t a k e , 3 days f o r adjustment t o 70% of ad_ l i b i t u m i n t a k e f o l l o w e d by 6 days f o r f e c a l c o l l e c t i o n .  The sheep  were  fed at  collected.  08:30  each  day  after  libitum  freezer  fecal  samples  and  orts  were  Feed o f f e r e d each day was a d j u s t e d so t h a t t h e l e v e l o f o r t s  remained a t about 10% o f i n t a k e . ad  which  intake  until  period  analysed.  was  T o t a l c o l l e c t i o n of the o r t s during the done  and  and  the m a t e r i a l  Feces were c o l l e c t e d  stored  and weighed  daily  r e p r e s e n t a t i v e sample o f 20% o f d a i l y f e c a l o u t p u t was c o l l e c t e d . samples were added  to previous  subsamples and  returned  to the  in a and  a  Fecal freezer  a f t e r each days c o l l e c t i o n . O r t s and f e c a l samples were c o m p o s i t e d w i t h i n periods. Feed, o r t s ground  through  and a  1  fecal mm  samples were d r i e d screen  using  a  a t 45°C f o r 48 h o u r s and  Wiley  mill  prior  to  further  analysis. 4.1.4. ANIMAL MANAGEMENT Seven S u f f o l k wether lambs were p u r c h a s e d about 6 weeks b e f o r e t h e s t a r t of the t r i a l .  When p u r c h a s e d , t h e lambs were about 3.5 months o f  age and had a mean w e i g h t o f 29.3  kg w i t h a range o f 26.8  t o 30.9  kg.  The a n i m a l s were housed i n d o o r s i n group pens u n t i l two weeks b e f o r e t h e s t a r t o f t h e t r i a l when t h e y were p l a c e d i n t h e m e t a b o l i s m cages.  While  housed i n t h e pens they were f e d a growing r a t i o n and were t r e a t e d w i t h and  a n t h e l m i n t i c wormed, g i v e n a c l o s t r i d i a l  innoculation,  treated f o r  sheep keds and g i v e n an i n j e c t i o n o f s e l e n i u m and v i t a m i n E.  There were  no h e a l t h problems o r problems w i t h a n i m a l s r e f u s i n g f e e d o v e r t h e e n t i r e trial  period.  4.1.5.  ANALYTICAL PROCEDURES  Lambs were weighed a t t h e end o f each p e r i o d . Feed, f e c e s and o r t s were a n a l a y z e d f o r CP u s i n g t h e m a c r o - K j e h d a h l technique  (AOAC, 1980) w i t h  copper as a c a t a l y s t .  The AD  and ND  fibre  t e c h n i q u e s of G o e r i n g and  Van  of  sulphate  decalin  and  sodium  Soest  (1970) were used w i t h t h e from  the  reagents.  exclusion  Dry  matter  d e t e r m i n a t i o n s were done as o u t l i n e d i n S e c t i o n 3.1.1. The  c o m p o s i t i o n o f the f o r a g e mixes f o r c l o v e r and g r a s s c o n t e n t i s  determined  by s e l e c t i n g 3 f l a k e s from a b a l e of each f e e d and t r i m m i n g  23cm x  23cm s e c t i o n  ensure  the  from  integrity  the m i d d l e  of  this  f o r 48  hours  c o m b i n a t i o n was of  a t 45°C and  t h e n determined  each f l a k e .  subsample  components were s e p a r a t e d by hand. dried  of  the  grass  Once s e p a r a t e d  weighed. and  The  and  to  legume  the components were  mean f o r each  treatment  t h i s r e p r e s e n t e d the r e l a t i v e  g r a s s and legume f o r t h e s i x t r e a t m e n t In  and  Care i s t a k e n  a  levels  combinations.  o r d e r t o i n t e g r a t e y i e l d w i t h the F e e d i n g T r i a l r e s u l t s CP  Yield  DE Y i e l d were c a l c u l a t e d as o u t l i n e d i n S e c t i o n 3.1.4. 4.2 The The  nutrient  dry matter  RESULTS  c o m p o s i t i o n of t h e hay  l e v e l s ranged  from 86.3  mixes was  t o 88.9%.  shown i n T a b l e  Crude p r o t e i n v a r i e d  l i t t l e between hay mixes w i t h EM l e v e l s r a n g i n g from 11.4 l e v e l s from 11.9  t o 12.7%.  w i t h a range of 34.5 to  41.7%  ADF  energy  (DE)  Mcal/kg  and  and  t o 37.8%  51.4  lowest  and 48.5 NDF  EM  ranging  ranging  from  2.24  LM  little  f o r EM, and  respectively.  from  and  levels varied  t o 54.9% NDF  f o r LM  f o r the  mix  and NDF  t o 11.5%  38.2  Digestible 2.42  t o 2.42  to  2.60  Mcal/kg.  a c o n t i n u o u s i n c r e a s e i n t h e l e v e l of the legume component  the EM mix  from 48  a  concurrent  drop  stable  52.6%  f o r the LM  in  the  to  ADF  l e v e l s were h i g h e s t  There was  However,  S i m i l a r i t y , ADF  4.2.  legume  ranging  from  t o 57  t o 74%  the  percent  in and 83  grass to  91%  f o r EB, MB  levels for  grass  and in  i n the the  FB r e s p e c t i v e l y w i t h  the LM  legume  mix  mix and  (Table  were 9  to  4.3).  relatively 17%  for  T a b l e 4.2  Nutrient  C o m p o s i t i o n o f Hay M i x e s  (Dry M a t t e r B a s i s ) .  NUTRIENT  Crude Protein (Z)  Hay M i x Early  Maturing(EM)  L a t e M a t u r i n g (LM)  NDF  DE  (%)  (%)  11.5 11.5 11.4  37.8 34.5 36.9  54.9 48.5 50.9  2.61 2.68 2.63  12.7 11.9 11.9  38.2 38.5 41.7  52.6 51.4 52.3  2.60 2.59 2.52  (Mcal/kg)  + +  E a r l y Bloom(EB) ' M i d Bloom (MB) F u l l Bloom (FB) 1  ADF  ,[,(  E a r l y Bloom(EB) M i d Bloom(MB) F u l l Bloom(FB)  + ADF = A c i d D e t e r g e n t F i b r e , NDF = N e u t r a l D e t e r g e n t F i b r e DE = D i g e s t i b l e Energy E s t i m a t e ( M a t h i s o n e t a l . , 1982) ++ EM = a l s i k e c l o v e r - t i m o t h y - bromegrass hay mix 1t EB,MB,FB = 102,50%,100% o f bloom o f t h e legume component of t h e f o r a g e mix. 1(11 LM = r e d c l o v e r - t i m o t h y hay mix.  T a b l e 4.3  Proportion  o f G r a s s and Legume i n Each Hay M i x Component Legume (%)  Hay M i x E a r l y Maturing(EM) E a r l y Bloom(EB) M i d Bloom(MB) F u l l Bloom(FB) L a t e M a t u r i n g (LM)^' E a r l y Bloom(EB) M i d Bloom(MB) F u l l Bloom(FB)  Grass (X)  + +  48 57 74  52 43 26  83 91 89  17 9 11  + EM = a l s i k e c l o v e r - t i m o t h y - bromegrass mix. ++ EB, MB, FB = 10%, 50%, 100% o f bloom o f t h e legume component o f t h e f o r a g e mix. 1! LM = r e d c l o v e r - t i m o t h y mix.  the g r a s s components  respectively.  T a b l e 4.4 shows t h e f e e d i n t a k e r e s u l t s o f t h e e a r l y m a t u r i n g f o r a g e mix compared w i t h t h e l a t e m a t u r i n g significant  d i f f e r e n c e (P ^ 0 . 0 1 )  except  detergent  readily  acid  consumed  1.02g/BW°''  fibre  than  t h e LM  (LM) f o r a g e m i x . There i s a  i n intake  intake  f o r a l l factors  (ADFI) w i t h  m i x . DMI  measured  t h e EM m i x b e i n g  f o r t h e EM  more  mix was 80.2 ±  and f o r t h e LM f o r a g e mix was 72.2 ± 1.02g/BW°'  75  (EM)  75  (P^O.01).  S i m i l a r i l y , t h e r e was a s i g n i f i c a n t d i f f e r e n c e ( P ^ O . 0 1 ) between t h e EM and LM f o r a g e 4.5).  DMD  mixes  for a l ldigestibility  factors  f o r t h e EM m i x was 64.9±0.43% v e r s u s  measured  (Table  61.2+0.43% f o r t h e LM  mix. There (P^O.01)  was  a  significant  and CPI ( P ^ O . 0 1 )  d i f f e r e n c e between  f o r ADFI, NDFI o r DMI  were  differences i n d i g e s t i b i l i t y  f a c t o r s measured w i t h 65.3  levels  f o r DOMI  b u t t h e r e was no s i g n i f i c a n t d i f f e r e n c e  between h a r v e s t s significant  harvests  (P>0.05)  (Table  4.6).  between h a r v e s t s  There  for a l l  o f 63.5%, 64.4% and 61.1% f o r DMD; 65.4,  and 61.6% f o r CPD; 5 4 . 1 , 51.7 and 49.9% f o r ADFD and 57.4, 54.3  and 51.2% f o r NDFD ( P ^ O . 0 1 )  f o r t h e EB, MB and FB h a r v e s t s r e s p e c t i v e l y  (Table 4.7). The Forage M i x X H a r v e s t  i n t e r a c t i o n was s i g n i f i c a n t  f o r DOMI and  CPI ( P ^ 0 . 0 5 ) b u t n o t f o r DMI, ADFI, NDFI, DMD, CPD, ADFD and NDFD (P>0.05). The e f f e c t s  due t o a n i m a l were  significant  ( P ^ I O . O I ) b u t n o t f o r any d i g e s t i b i l i t y Similarily,  the effects  factor  due t o p e r i o d were  f o r a l l intake except  significant  ADFD  factors  (P>0.05).  f o r a l l intake  f a c t o r s (DMI, DOMI, CPI (p^0.05 ) ; ADFI, NDFI ( p ^ O . O l ) ) b u t n o t f o r any of the d i g e s t i b i l i t y f a c t o r s (P>0.05).  TABLE 4.4  Means o f I n t a k e Parameters f o r E a r l y M a t u r i n g and L a t e M a t u r i n g Forage M i x e s .  DMI Hay M i x  EM LM  SEM +  + +  1[  DOMI  CPI  NDFI  (g/day)  (g/day)  (g/BW°' )  (g/BW°* )  80.2  a  48.l  a  158  a  485  a  685  a  72.7  b  41. l  b  144  b  477  a  640  b  75  1.02  75  0.66  (g/day)  ADFI  2.77  7.98  9.81  DMI = D r y M a t t e r Intake;, DOMI = D i g e s t i b l e O r g a n i c M a t t e r I n t a k e ; CPI = Crude P r o t e i n I n t a k e ; ADFI = A c i d D e t e r g e n t F i b r e I n t a k e ; NDFI = N e u t r a l D e t e r g e n t Fibre Intake; ++ EM Forage M i x = a l s i k e c l o v e r , t i m o t h y , and bromegrass. 11 LM Forage M i x = r e d c l o v e r and t i m o t h y . 1(11 SEM = S t a n d a r d E r r o r o f t h e Mean a,b Means w i t h i n columns w i t h d i f f e r e n t s u p e r s c r i p t s a r e different (P^0.05).  TABLE 4.5  Means o f D i g e s t i b i l i t y Parameters and L a t e M a t u r i n g Forage M i x e s .  DMD Hay M i x  EM LM  + +  11  SEM™ +  +  (%)  64.9  a  61.2  0.43  b  For Early Maturing  CPD  ADFD  NDFD  (%)  (%)  (%)  66.l  a  54.7  a  57.3  a  62.0  b  49.l  b  51.3  b  0.54  0.62  0.72  DMD = Dry M a t t e r D i g e s t i b i l i t y ; CPD = Crude P r o t e i n D i g e s t i b l i t y ; . ADFD = A c i d D e t e r g e n t f i b r e D i g e s t i b i l i t y ; NDFD = N e u t r a l D e t e r g e n t F i b r e D i g e s t i b l i t y . ++ EM Forage M i x = a l s i k e c l o v e r , t i m o t h y , and bromegrass. II LM Forage M i x = r e d c l o v e r and t i m o t h y . SEM = S t a n d a r d E r r o r o f t h e Mean a,b Means w i t h i n columns w i t h d i f f e r e n t s u p e r s c r i p t s a r e d i f f e r e n t (P<.0.05).  TABLE 4.6  Means o f I n t a k e P a r a m e t e r s f o r Bloom H a r v e s t s .  DMI Harvest  DOMI  +  E a r l y , M i d and F u l l  CPI  ADFI  NDFI  (g/BW ' )  (g/BW ' )  76.2  a  45.l  a  157  a  482  a  682  a  Mid Bloom  78.6  a  46.6  a  154  a  479  a  656  a  Full Bloom  74.4  a  42.2  b  140  b  481  649  a  SEM  1.25  ,  Early Bloom  +  11  0  75  0  75  (g/day)  (g/day)  (g/day)  ++  0.81  3.40  a  9.77  12.01  DMI = Dry M a t t e r I n t a k e ; DOMI = D i g e s t i b l e O r g a n i c M a t t e r I n t a k e ; CPI = Crude P r o t e i n I n t a k e ; ADFI = A c i d D e t e r g e n t F i b r e I n t a k e ; NDFI = N e u t r a l D e t e r g e n t Fibre Intake. ++ E a r l y , M i d and F u l l Bloom = 10%, 50% and 100% of bloom o f t h e legume component o f t h e f o r a g e . 11 SEM = S t a n d a r d E r r o r o f t h e Mean a,b Means w i t h i n columns w i t h d i f f e r e n t s u p e r s c r i p t s a r e different (P^0.05).  TABLE 4.7  Means o f D i g e s t i b i l i t y P a r a m e t e r s f o r E a r l y , M i d and F u l l Bloom H a r v e s t s .  DMD Harvest Early Bloom  +  (%)  CPD  ADFD  NDFD  (X)  (%)  (%)  + +  63.5  a  65.4  a  54. l  Mid Bloom  64.4  a  65.3  a  51.7  Full Bloom  61. l  61.6  b  49.9  SEM ' 1  +  0.53  b  0.66  0.76  57.3  a  b  54.3  b  b  51.2  C  a  0.88  DMD = Dry M a t t e r D i g e s t i b i l i t y ; CPD = Crude P r o t e i n D i g e s t i b l i t y ; ADFD = A c i d D e t e r g e n t f i b r e D i g e s t i b i l i t y ; NDFD = N e u t r a l D e t e r g e n t F i b r e D i g e s t i b l i t y . ++ E a r l y , M i d and F u l l Bloom = 10%, 50% and 100% o f bloom o f the legume component o f t h e f o r a g e . 11 SEM = S t a n d a r d E r r o r o f t h e Mean a,b Means w i t h i n columns w i t h d i f f e r e n t s u p e r s c r i p t s a r e different (P^0.05).  Even though t h e r e were o n l y s i x d a t a p o i n t s , t h e RSQUARE is  used  predict  t o determine  i f a regression equation  DMI, DOMI o r DMD  codfficients  (Table  of determination  4.8).  based  a  l i t t l e from t h o s e based on m u l t i p l e f a c t o r s . improvement i n p r e d i c t a b i l i t y  c o u l d be developed  The r e s u l t s  upon  procedure  single  indicate factor  to  that the  would  vary  Thus, t h e r e would be l i t t l e  w i t h equations  based on t h e s e  results i f  more than one f a c t o r was i n c l u d e d i n t h e r e g r e s s i o n e q u a t i o n .  Overall,  t h e r e were no c o e f f i c i e n t s o f d e t e r m i n a t i o n s u f f i c i e n t l y l a r g e t o w a r r e n t developing a p r e d i c t i v e equation. The DE v a l u e s used t o e s t i m a t e DEY i n T a b l e 4.9 were c a l c u l a t e d from t h e ADF v a l u e s could  shown i n T a b l e  be e s t i m a t e d  freedom  t o analyse  4.1.  and t h e r e f o r e the calculated  Only  there  6 values were  values  f o r each parameter  insufficient  using  an ANOVA  degrees o f procedure.  However, when t h e CPY and DEY v a l u e s were examined t h e LM m i x had g r e a t e r DE and CP y i e l d s than t h e LM mix.  As w e l l , each o f t h e DE and CP y i e l d s  i n c r e a s e d from t h e EB t o t h e FB h a r v e s t .  T a b l e 4.8  C o e f f i c i e n t s o f D e t e r m i n a t i o n f o r S i m p l e and M u l t i p l e F a c t o r Models  Dependent V a r i a b l e R-Square Number o f F a c t o r s i n Model  1 1 1 2 2 2  3  Factor i n Model  CP™ ADF NDF CP ADF CP NDF ADF NDF CP ADF NDF  DMI  Values  DOMI  DMD  0.020 0.109 0.143  0.034 0.184 0.195  0.038 0.195 0.460  0.109 0.144 0.145  0.188 0.195 0.211  0.199 0.470 0.487  0.145  0.211  0.498  1t  11 DMI = D r y M a t t e r I n t a k e , DOMI = D i g e s t i b l e O r g a n i c M a t t e r I n t a k e DMD = D r y M a t t e r D i g e s t i b i l i t y . 1111 CP = Crude P r o t e i n , ADF = A c i d D e t e r g e n t F i b r e , NDF = N e u t r a l Detergent F i b r e  T a b l e 4.9  Hay M i x , H a r v e s t Date and Y i e l d o f T e s t Forages  Hay M i x  CP Y i e l d (T/ha)  Yield, (Meals x 10 /ha)  E a r l y M a t u r i n g (EM)* ++ E a r l y Bloom (EB) M i d Bloom (MB) F u l l Bloom (FB)  July 9 J u l y 15 J u l y 22  5.6 7.6 9.4  L a t e M a t u r i n g (LM) E a r l y Bloom (EB) M i d Bloom (MB) F u l l Bloom (FB)  J u l y 22 J u l y 30 August 8  9.2 9.9 11.0  + EM = a l s i k e c l o v e r - t i m o t h y - bromegrass f o r a g e mix. ++ EB,MB,LB = 102,502 1002 o f bloom o f t h e legume component of t h e f o r a g e mix. It E s t i m a t e f o r EM-EB based on known w e i g h t o f a i r d r y m a t e r i a l removed from 0.1 ha. 1111 LM = r e d c l o v e r t i m o t h y f o r a g e mix.  4.3 4.3.1  INTAKE AND According  ADF  to  level  DIGESTIBILITY  t o Van  Soest  digestibility. of  EM  DISCUSSION  was  (1982) NDF  Therefore  lower  than  was  b e t t e r r e l a t e d to i n t a k e  i t should  the  NDF  follow that, since  level  of  LM  the  EM  mix  consumed i n g r e a t e r amounts t h a n the LM mix.  W h i l e t h i s was  difference  was  between  EM  and  LM  NDF  levels  small  The  difference  respectively)  was  i n d i c a t e d by Van between the two DMI  obtained  1961;  larger  mixes.  than  the  EM  and  difference  in  may  intake  of  The  forages  the LM mix  that  time  retention t o EM  and  the i n t a k e of LM the  i n the  digestibility  below 66% w h i l e  Since  LM NDF  with  was  therefore  true  consumed  each  digestibility  mix  was  42.1%  and,  as  digestibility  ( B l a x t e r et a l . , greater  i n t a k e of  l i m i t e d by rumen  only  dilution  passage r a t e of  and  dilution  rate  1 percentage p o i n t This indicates  rate  the  fill.  decreased  forage  was  in  slowed  LM and  reduced. i n t a k e of dry m a t t e r was  f o l l o w t h e n , t h a t CPI, NDFI AND was  and  vs  levels  i s 5 percentage p o i n t s lower. increased  52.1%  digestibilities  rumen i n c r e a s e s  of the EM  be  vs  (39.7  l i m i t e d by the a n i m a l ' s r e q u i r e m e n t f o r energy and  time  would  a l s o e x p l a i n the d i f f e r e n c e i n  w i t h d i g e s t i b i l i t i e s of l e s s t h a n 66% was  decreases.  This  between  Digestibility  that  addition, retention  relative  levels  NDF  DMI.  Soest ( 1 9 8 2 ) , e x p l a i n s the d i f f e r e n c e s i n  1971)  t h a n 66% was  In  ADF  between the two m i x e s . I t has been r e p o r t e d  Bines,  forages  in  the  the case the  (51.8  r e s p e c t i v e l y ) and would not account f o r the d i f f e r e n c e i n  and  greater  than LM  i t would  ADFI would a l s o be s i g n i f i c a n t l y  greater.  i n a l l cases e x c e p t ADFI and forage s i n c e the  to  the  point  i n t a k e of ADF  where  f o r EM  indicated that intake  was  the  animal  limited  (the f i b r e f r a c t i o n r e l a t i n g  by best  w i t h d i g e s t i b i l i t y ) was n o t d i f f e r e n t between m i x e s . The  differences  i n t h e d i g e s t i b i l i t y o f t h e CP, ADF  f r a c t i o n s would r e l a t e t o t h e i n c r e a s e d energy a v a i l a b l e allowing of  f o r greater microbial  the c e l l  wall  component  indigestible fibrous material  cell  This  Mid  as a r e s u l t  digestion  result  from a  percentage of  (Van S o e s t , 1982).  and d i g e s t i b i l i t y i t would  different  would  c o n t e n t s and a l e s s e r  S i n c e t h e r e were s i g n i f i c a n t d i f f e r e n c e s intake  from t h e EM mix  a c t i v i t y and t h e r e f o r e g r e a t e r  of the p l a n t .  greater percentage of soluble  and NDF  also  between EM and LM f o r b o t h follow  of the combination  that  of factors  DOMI just  would  be  discussed.  There was no s i g n i f i c a n t d i f f e r e n c e  i n DMI between t h e E a r l y ( E B ) ,  (MB) and F u l l Bloom (FB) h a r v e s t s .  T h i s r e s u l t would be e x p e c t e d  based on t h e s m a l l v a r i a t i o n  i n NDF l e v e l s  (38.0,36.5 and 39.3% r e s p e c t i v e l y ) .  o c c u r r i n g between h a r v e s t s  A g a i n , as e x p e c t e d , ADFI and NDFI  l e v e l s were n o t s i g n i f i c a n t l y d i f f e r e n t , however, CPI l e v e l s were l o w e r for  FB t h a n f o r EM and MB h a r v e s t s .  T h i s may be due t o t h e s l i g h t l y  l o w e r DMI f o r FB c o u p l e d w i t h a s l i g h t l y l o w e r CP l e v e l r e l a t i v e t o EM and MB ( 1 2 . 1 , 11.7 and 11.65% r e s p e c t i v e l y ) . The DMD r e s u l t s  f o r EB, MB and FB c l o s e l y  (38.0, 36.5 and 39.3% r e s p e c t i v e l y )  o b t a i n e d i n each h a r v e s t i n t h a t t h e  FB-ADF l e v e l s were h i g h e r w h i l e DMD was l o w e r . NDFD  levels  f o r FB were  e x p e c t e d , t h e FB m a t e r i a l harvested fibre  intakes  different, energy  material. were  lower  p a r a l l e l t h e ADF l e v e l s  than  As w e l l , CPD, ADFD and  EB and MB  indicating  that,  as  was o f l o w e r n u t r i t i o n a l v a l u e than t h e e a r l i e r  Since equal  each even  feed though  was consumed fibre  levels  to the point i n the feed  energy v a l u e s must impact on d i g e s t i b i l i t y s i n c e  (DE) e s t i m a t e s were l o w e s t i n t h e FB h a r v e s t  where were  digestible  (2.35 v s . 2.42 and  2.49  Mcals/kg  f o r FB, EB and MB  r e s p e c t i v e l y ) as p r e d i c t e d from ADF  values. DOMI was s i g n i f i c a n t l y h i g h e r f o r EB and MB than f o r FB h a r v e s t s due to a combination  of higher  i n t a k e s and d i g e s t i b i l i t i e s  f o r the e a r l i e r  cut h a r v e s t s . O v e r a l l , t h e s e r e s u l t s i n d i c a t e t h a t t h e EM f o r a g e mix h a r v e s t e d a t the mid-bloom s t a g e was t h e b e s t f o r a g e based on i n t a k e and d i g e s t i b i l i t y parameters.  F o r t h e most p a r t , i n t e r a c t i o n s between hay m i x and h a r v e s t  were n o t s i g n i f i c a n t , however a s i g n i f i c a n t DOMI and CPI.  F o r DOMI t h e i n t e r a c t i o n may be e x p l a i n e d by t h e degree o f  v a r i a t i o n between t h e v a l u e s relative for  to the values  the f i r s t  (48.0  i n t e r a c t i o n i s obtained f o r  f o r t h e EM and LM mixes a t t h e FB h a r v e s t  o b t a i n e d a t t h e EB and MB h a r v e s t s .  two h a r v e s t s were much c l o s e r  than  f o r the l a s t  v s . 42.2, 42.2 v s 44.2 and 47.5 v s . 37.0 g/BW a t t h e EB, MB  and FB s t a g e s  The v a l u e s  0  ,  7  5  harvest  f o r t h e EM and  LM mixes  harvested  respectively).  situation  f o r CPI was t h e same w i t h t h e EM and LM v a l u e s b e i n g  The  160 v s .  155  ,157 v s . 151 and 157 v s . 125 g f o r t h e EM and LM mixes h a r v e s t e d a t  the  EM, MB  and FB s t a g e s  respectively.  Thus b o t h  interactions  s i g n i f i c a n t due t o l a r g e r d i f f e r e n c e s i n t h e v a l u e s o f t h e l a s t relative  to the e a r l i e r  h a r v e s t s , n o t due t o one mix h a v i n g  were  harvest a higher  v a l u e f o r a d e t e r m i n a t i o n a t one h a r v e s t date and t h e o t h e r m i x h a v i n g a h i g h e r v a l u e a t another  date.  W i t h t h e e x c e p t i o n o f ADFD t h e r e was no e f f e c t on any d i g e s t i b i l i t y d e t e r m i n a t i o n due t o t h e t e s t effect  of test  parameters. and  animal  animal  and t e s t  or the test period.  p e r i o d was s i g n i f i c a n t  However, t h e  f o r a l l intake  There was a 13% d i f f e r e n c e i n t h e l i v e w e i g h t o f t h e l a r g e s t  s m a l l e s t sheep a t t h e time  o f purchase and t h i s v a r i a t i o n  i n size  continued  t h r o u g h t o t h e end o f t h e t r i a l p e r i o d a t w h i c h p o i n t t h e r e was  a range o f about 5 kg ( o r 10%) i n a n i m a l l i v e w e i g h t between t e s t sheep. Since  food  consumption  increases  with  increasing  liveweight  at a  comparable f a t n e s s ( M e i j s , 1982) i t would be e x p e c t e d t h a t t h e r e would be differences  i n intake  Similarily,  i t would be e x p e c t e d t h a t d i f f e r e n c e s i n i n t a k e would  between  test  periods  between  because  animals  the t e s t  a t any t i m e  a n i m a l s were  during  still  the t r i a l . occur  growing and  t h e i r w e i g h t s i n c r e a s e d an average o f 9.4 k g s o r about 25% o f t o t a l body w e i g h t from t h e s t a r t increases  of the t r i a l .  Weston and Margan (1979)  reported  i n t h e i n t a k e o f sheep on t r i a l between t h e ages o f 24 and 40  weeks (compared w i t h 21 t o 39 weeks o f age f o r sheep used i n t h i s s t u d y ) of about 20% o f t h e i n t a k e a t 24 weeks o f age. in  i n t a k e over the t r i a l  This l e v e l of v a r i a t i o n  p e r i o d would c e r t a i n l y r e s u l t  i n t a k e p a r a m e t e r s due t o p e r i o d .  i n an e f f e c t on  These a u t h o r s a l s o r e p o r t e d a s m a l l b u t  s i g n i f i c a n t decrease i n the l e v e l of c e l l w a l l c o n s t i t u e n t s digested i n the  alimentary  t r a c t between t h e ages o f 24 and 40 weeks.  were n o t c o n s i d e r i n g related  d i f f e r e n c e s between  t o t h e changing  significant  size  of the test  animals  this  While  effect  they  must be  a n i m a l s and may e x p l a i n t h e  e f f e c t o f a n i m a l on ADFD s i n c e t h e r e was a 10% v a r i a t i o n i n  animal l i v e w e i g h t . 4.3.2  UNCONTROLLED FACTORS There  were  two major  uncontrolled  impact on t h e outcome o f t h e e x p e r i m e n t . 1)  factors  that  These were:  t h e p r e c i p i t a t i o n t h a t was r e c e i v e d by t h e EM-EB, EM-FB and LM-EB f o r a g e s , and  2)  the r e l a t i v e l e v e l of grasses each f o r a g e mix and h a r v e s t .  and c l o v e r s i n  may  have  had an  While falling  no measurements were  on  the  precipitation,  site  there  usually  taken  were  falling  later  of the a c t u a l  at  least  amounts  several  i n the drying  of r a i n  millimeters  period.  of  Anderson  (1976) i n d i c a t e d t h a t a r e l a t i v e l y heavy r a i n i m m e d i a t e l y a f t e r c u t t i n g w i l l do m i n i m a l damage i f f o l l o w e d by f a v o u r a b l e weather whereas t h e same amount o f r a i n on d r y hay can cause heavy n u t r i e n t l o s s e s . (1983, 1985) and Fonnesbeck et_ al^. (1982) r e p o r t e d  Both C o l l i n s  that wetting  d i d not  change t h e p e r c e n t a g e o f N i n t h e hay, however t h e r e was i n c r e a s e d and o v e r a l l d r y m a t t e r l o s s e s w i t h t h e e f f e c t s b e i n g t h a n a t bloom s t a g e  i n red clover.  leaf  g r e a t e r a t bud s t a g e  Fonnesbeck et^ a l . (1982)  reported  t h a t t h e s e d r y m a t t e r l o s s e s were i n t h e range o f 10% a f t e r 20 mm o f r a i n fell  representing  the soluble  p o r t i o n of the p l a n t . c e l l w a l l increased  ash, l i p i d  and a v a i l a b l e  carbohydrate  W i t h i n c r e a s i n g amounts o f r a i n t h e p e r c e n t a g e o f  (Fonnesbeck et_ a l . , 1982) r e s u l t i n g i n i n c r e a s e d  ADF  and NDF l e v e l s ( C o l l i n s 1983, 1985). These o b s e r v a t i o n s mixes. 5.7)  There was l i t t l e  since  there  was  harvests,  but r a i n f a l l  According  t o Van Soest  increase increases both  with  e f f e c t on CP l e v e l due t o p r e c i p i t a t i o n (Table  little  difference  between w e t t e d  and r a i n  does appear t o have a f f e c t e d ADF and NDF (1982) t h e amount o f c e l l w a l l m a t e r i a l  increasing  plant  i n ADF and NDF v a l u e s  the early  greater  h e l p e x p l a i n t h e n u t r i e n t c o m p o s i t i o n o f t h e hay  and l a t e  mixes.  maturity.  This  was  evidenced  free  levels. should by t h e  between M i d and F u l l Bloom h a r v e s t s f o r However, b o t h  f o r EB t h a n f o r MB and FB (except  fibre  measurements a r e  f o r ADF i n t h e LM mix) and  s i n c e b o t h EB-EM and EB-LM r e c e i v e d p r e c i p i t a t i o n t h i s would e x p l a i n t h i s unexpected r e s u l t . The  second u n c o n t r o l l e d  f a c t o r was t h e s p e c i e s  composition  (Table  4.2). all  The l e v e l o f r e d c l o v e r i n t h e LM mix was h i g h e r than expected f o r  harvests  and t h e l e v e l  of a l s i k e  between t h e EB and FB h a r v e s t s . than what would be expected  c l o v e r i n t h e EM mix i n c r e a s e d  The l e v e l s o f b o t h c l o v e r s were h i g h e r  when t h e percentage  o f each i n t h e seed mix  was c o n s i d e r e d . Collins  (1985)  reported  that  in a  r e d clover-smooth  m i x t u r e t h e r e d c l o v e r made up about 92% o f t h e t o t a l m i x t u r e . (1981,  1984) a l s o r e p o r t e d  mixes i n w h i c h t i m o t h y  similar  findings with  bromegrass McBratney  r e d c l o v e r and g r a s s  c o n t r i b u t e d t h e l e a s t o f any o f t h e t e s t  t o t h e t o t a l DM y i e l d .  grasses  The a u t h o r i n d i c a t e d t h a t t h i s c o n c e n t r a t i o n was  about 15% o f t h e y i e l d o v e r s e v e r a l y e a r s . S i n c e legumes tend t o m a i n t a i n t h e i r n u t r i t i v e v a l u e l o n g e r through t h e growing Soest,  1982)  constituents  and and  alfalfa  and  digestible  red  fibre  clover  season than g r a s s e s (Van  are  and h i g h e r  lower  i n cell  p e r e n n i a l r y e g r a s s a t s i m i l a r growth s t a g e s (Campling, expected  in cell  wall  solubles  than  1984), i t would be  t h a t h i g h l e v e l s o r i n c r e a s i n g l e v e l s o f legumes i n t h e m i x t u r e  would reduce t h e d i f f e r e n c e s i n f e e d v a l u e between EB and FB h a r v e s t s . In combination levels  then,  the r a i n f a l l  o f legume i n t h e FB h a r v e s t s  n u t r i e n t l e v e l s between h a r v e s t s .  on t h e EB h a r v e s t s and t h e h i g h acted  t o reduce  the v a r i a t i o n i n  T h i s would p a r t i a l l y e x p l a i n why t h e r e  was no d i f f e r e n c e i n any i n t a k e parameters o r i n DMD and CPD between EB and MB h a r v e s t s even though a d i f f e r e n c e c o u l d be e x p e c t e d . 4.3.3 LINEAR AND QUADRATIC REGRESSION ANALYSIS The  coefficients  of determination  were a l l l e s s  than 0.5.  e s t i m a t i n g DMD  from NDF d e t e r m i n a t i o n s .  obtained  by r e g r e s s i o n a n a l y s i s  The h i g h e s t c o e f f i c i e n t o b t a i n e d was t h a t f o r The r e g r e s s i o n c o e f f i c i e n t s f o r  DMD u s i n g m u l t i p l e f a c t o r s d i d n o t i n c r e a s e s i g n i f i c a n t l y .  T h i s may be  expected  since  Narasimhalu  only  et^ a l .  s i x data (1982)  points  reported  were  that  used  neither  i n the NDF  analysis.  n o r ADF  were  c o r r e l a t e d w i t h DMD i n work done on o r c h a r d g r a s s , bromegrass o r t i m o t h y . A d e r i b i g b e et^ a l . (1982) i n a t r i a l w i t h r y e g r a s s e s r e p o r t s t h e r e was no r e l a t i o n s h i p between CP and DMI — this  a r e s u l t s i m i l a r to that obtained i n  trial. The  d i f f e r e n c e i n a c t u a l i n t a k e and d i g e s t i b i l i t y  F e e d i n g T r i a l and t h a t suggested discussed  i n the previous  relatively  low c o e f f i c i e n t s  laboratory  results  great  deal  upon  section,  further  of determination  support  the finding  obtained  when r e g r e s s i n g  parameters.  t o be accounted  d i g e s t i b i l i t y o f f e e d s t u f f s by ruminants 4.3.4  of the  by t h e r e s u l t s o f t h e V a r i e t y T r i a l , as  digestibility  of variation  results  of  There was s t i l l  f o r before  a  t h e i n t a k e and  can be p r e d i c t e d .  INTEGRATED RESULTS WITH YIELD When q u a l i t y  parameters were i n t e g r a t e d w i t h t h e y i e l d  o f t h e two  hay mixes o v e r t h e t h r e e h a r v e s t s d i f f e r e n t c o n c l u s i o n s were reached when j u s t q u a l i t y parameters were c o n s i d e r e d . l o w e r i n i n t a k e and d i g e s t i b i l i t y  than  Even though t h e LM mix i s  i t was h i g h e r y i e l d i n g .  Thus, i n terms  of CP and energy produced from a g i v e n a r e a o f l a n d t h e LM mix was more p r o d u c t i v e t h a n t h e EM mix.  When c o n s i d e r i n g t h e v a l u e o f a g i v e n f o r a g e  s p e c i e s o r mix, y i e l d as w e l l as q u a l i t y must be c o n s i d e r e d . 4.3.5  COMPARISON WITH VARIETY TRIAL RESULTS The  i n t a k e and d i g e s t i b i l i t y  between hay mixes v a r y  somewhat  r e s u l t s obtained i n the feeding from what would be expected  laboratory r e s u l t s obtained i n the v a r i e t y t r i a l . clover  and r e d c l o v e r were n o t s i g n i f i c a n t l y  trial  based on  NDF l e v e l s f o r a l s i k e  different  suggesting  the i n t a k e s o f t h e two c l o v e r s would a l s o n o t be d i f f e r e n t .  that  In would  terms  again  of d i g e s t i b i l i t y ,  suggest  NBDMD r e s u l t s  no d i f f e r e n c e s  from  between mixes  s i g n f i c a n t d i f f e r e n c e between r e d and a l s i k e c l o v e r .  the v a r i e t y  since  there  trial  was no  With regard  to the  g r a s s component o f each hay m i x t h e r e s u l t s of Seone e t a l . (1981b) f o r NBDMD suggested t h a t Toro was more d i g e s t i b l e t h a n C l i m a x (45.4 disappearance r e s p e c t i v e l y ) .  This  agrees w i t h  the feeding  v s . 35.7%  trial  result  i n t h a t the EM ( c o n t a i n i n g Toro t i m o t h y ) was more d i g e s t i b l e t h a n the LM mix  (containing Climax timothy).  i n each m i x a t a l l h a r v e s t s The of  ADF v a l u e s o b t a i n e d the feeding  trial  were s i g n i f i c a n t l y indicates  that  would l i m i t the v a l i d i t y  of t h i s  observation.  i n the V a r i e t y T r i a l a l s o c o n t r a d i c t the r e s u l t s  i n that  greater  the levels for a l s i k e clover  than f o r the r e d c l o v e r  the red clover  a l s i k e c l o v e r mix.  However, the l a r g e p e r c e n t a g e o f legume  (32.2±1.10%)  (30.9±0.65%).  This  m i x s h o u l d be more d i g e s t i b l e t h a n t h e  Seone e t a l . (1981b) found o n l y a 1.7% d i f f e r e n c e i n  DMD between Toro and C l i m a x t i m o t h y v a r i e t i e s .  CHAPTER 5 - GENERAL DISCUSSION AND CONCLUSIONS The  experiments  conducted  i n t h i s s t u d y examined s e v e r a l a s p e c t s o f  f o r a g e q u a l i t y ( i n terms o f a n i m a l n u t r i t i o n ) i n c l u d i n g t h e d i f f e r e n c e s between  Type,  Species  and V a r i e t i e s  within  species;  between y e a r s ; t h e d i f f e r e n c e s between two f o r a g e mixes; between t h r e e h a r v e s t  dates  and t h e importance  the differences the differences  of q u a l i t y r e l a t i v e to  yield. In  general,  this  study  showed  that  t h e legumes  were  of  better  n u t r i t i o n a l q u a l i t y t h a n g r a s s e s ; t h a t t h e c l o v e r s were o f b e t t e r q u a l i t y than a l f a l f a ,  and t h a t o r c h a r d g r a s s was o f b e t t e r q u a l i t y t h a n  When t h e n u t r i t i o n a l only  q u a l i t y of v a r i e t i e s w i t h i n  s p e c i e s was examined,  the r e d c l o v e r v a r i e t i e s (Altaswede, P a c i f i c  significant  differences.  timothy.  and L a k e l a n d )  T h e r e f o r e , t h e r e was no d i f f e r e n c e  showed  i n quality  between those a l f a l f a , o r c h a r d g r a s s o r t i m o t h y v a r i e t i e s examined.  Over  the 3 study y e a r s , t h e r e were d i f f e r e n c e s i n CP and NDF b u t n o t i n ADF o r NBDMD  indicating  quality  between  there  would  years  but  be  a  there  difference  i n intake  would  little  be  and o v e r a l l  difference  in  d i g e s t i b i l i t y o f t h e t e s t f o r a g e s between y e a r s . The had  r e s u l t s o f t h e F e e d i n g T r i a l showed t h a t t h e e a r l y m a t u r i n g mix  higher  intake  and d i g e s t i b i l i t y  than  the l a t e maturing  mix.  An  e x a m i n a t i o n o f t h e s p e c i e s c o m p o s i t i o n r e v e a l e d t h a t t h e c l o v e r s made up a  major  effect  portion on  different trial. clover  o f each m i x and t h e r e f o r e  intake than  and d i g e s t i b i l i t y .  would be e x p e c t e d  There was no d i f f e r e n c e i n the V a r i e t y  different.  Trial  based  would have had t h e l a r g e s t  The F e e d i n g  Trial  results are  on t h e r e s u l t s o f t h e v a r i e t y  i n NDF l e v e l s between r e d and a l s i k e  suggesting  that  intakes  would  n o t be  A l s o , a l s i k e c l o v e r had s i g n i f i c a n t l y h i g h e r ADF v a l u e s  than  r e d c l o v e r ( a l t h o u g h NBDMD v a l u e s were not d i f f e r e n t ) s u g g e s t i n g c l o v e r i s more d i g e s t i b l e than a l s i k e c l o v e r . a l s i k e c l o v e r mix was while  the  red  comparison  of  I n the F e e d i n g T r i a l  the  consumed a t g r e a t e r l e v e l s than the r e d c l o v e r mix  c l o v e r was results  that red  l e s s d i g e s t i b l e t h a n the a l s i k e c l o v e r .  from  laboratory determinations  each  trial  illustrates  the  point  This  that  the  used t o p r e d i c t a p a r t i c u l a r f e e d i n g parameter  s t i l l have g r e a t v a r i a b i l i t y a s s o c i a t e d w i t h them. Differences harvests. value  were  T h i s was  also  found  in  intake  and  digestibility  between  e x p e c t e d s i n c e t h e p l a n t s mature and l o s e n u t r i t i o n a l  o v e r the growing season r e s u l t i n g i n a p r o g r e s s i v e drop i n f o r a g e  q u a l i t y from h a r v e s t t o h a r v e s t .  However, the r e s u l t s of t h i s study were  not as e x p e c t e d w i t h the e a r l y bloom h a r v e s t b e i n g of s i m i l a r q u a l i t y t o the mid  bloom, b o t h of w h i c h were o f b e t t e r q u a l i t y than the l a t e bloom  harvest.  F u r t h e r m o r e , NDF  and  ADF  values  f o r the  e a r l y bloom  harvest  were as h i g h o r h i g h e r than the l a t e r h a r v e s t s , c o n t r a r y t o e x p e c t a t i o n s . These  results  may  be  explained  by  two  uncontrolled  p r e c i p i t a t i o n and  the  l e v e l o f legume i n each f o r a g e mix.  worked  the  variability  to  reduce  between h a r v e s t s  p r e c i p i t a t i o n can have a l a r g e n e g a t i v e the l e v e l o f legume i n the mix o c c u r r e d w i t h the EM  mix)  e f f e c t on  and forage  factors  -  Both f a c t o r s  point  out  quality,  that while  ( e s p e c i a l l y i f the p r o p o r t i o n i n c r e a s e s  can have a l a r g e p o s i t i v e i n f l u e n c e on  as  forage  quality. However, the  factor with  the l a r g e s t v a r i a t i o n , whether d i s c u s s i n g  d i f f e r e n c e s between f o r a g e s , y e a r s , f o r a g e m i x e s , or h a r v e s t yield. years  I n the f e e d i n g t r i a l , due  three years  to the  different  dates,  the l a r g e s t d i f f e r e n c e i n y i e l d was  between  growing c o n d i t i o n s o c c u r r i n g i n each o f  t h a t samples were c o l l e c t e d f o r the v a r i e t y t r i a l .  was  The  the next  largest and  d i f f e r e n c e occurred  the  least  exception  was  differences and  difference i n yield i n t h e case  was  species  between  o f r e d c l o v e r where  or forage  varieties. t h e r e was  trial,  yielding  the largest  mixes,  The  one  considerable  i n y i e l d between v a r i e t i e s w i t h A l t a s w e d e b e i n g  P a c i f i c the lowest  variety  between d i f f e r e n t  the h i g h e s t  o f a l l t h e v a r i e t i e s examined.  I n the  d i f f e r e n c e i n y i e l d was between hay mixes and  then between h a r v e s t s . Y i e l d and q u a l i t y r e s u l t s may be i n t e g r a t e d by d e t e r m i n i n g t h e y i e l d of n u t r i e n t s p e r h e c t a r e i n d i c a t i n g t h e n u t r i e n t p r o d u c t i o n o f one f o r a g e relative  to another.  Different  c o n c l u s i o n s were reached  i n the of red  c l o v e r when b o t h y i e l d and q u a l i t y were c o n s i d e r e d .  L a k e l a n d and P a c i f i c  v a r i e t i e s were the h i g h e s t  quality  but Lakeland  i s the  lowest,  intermediate,  Altaswede  i s of  and  Pacific  only  forages  on t e s t in yield.  somewhat lower q u a l i t y than t h e o t h e r two r e d c l o v e r v a r i e t i e s b u t i s t h e highest y i e l d i n g produced  forage o v e r a l l .  the l e a s t  Therefore,  the highest q u a l i t y  amount o f n u t r i e n t s p e r h e c t a r e  while  forage  t h e somewhat  lower q u a l i t y b u t much h i g h e r y i e l d i n g A l t a s w e d e v a r i e t y y i e l d e d f a r more nutrients  per  recommend  t h e lower  based on these of  yield  hectare.  Orchardgrass  quality  results.  relative was  In a  practical  but higher  situation yielding  one  Altaswede  yields  nutrients  red clover  to quality of b e t t e r  occurred  quality  with  than  orchardgrass  timothy  and  b u t because  timothy. timothy  i s greater f o r  A f i n a l example was from t h e f e e d i n g t r i a l where t h e EM mix was  of b e t t e r q u a l i t y higher  to  A n o t h e r more g e n e r a l example o f t h e importance  produced more f o r a g e , t h e y i e l d o f n u t r i e n t s p e r h e c t a r e timothy.  w o u l d have  than  of f o r a g e  per hectare.  t h e LM mix; however, s i n c e t h e LM mix produced than  t h e EM m i x , the LM mix p r o v i d e d  Thus, u n l e s s  there  was  a vast  t h e most  difference i n  quality  between two f o r a g e s ,  provide  the beef  cattle  the forage  producer  with  with  the highest  t h e most y i e l d  yield  will  of n u t r i e n t s per  hectare. One must temper these  conclusions, especially  red c l o v e r , w i t h other c o n s i d e r a t i o n s . of the harvested  those  regarding  I n t h e case o f r e d c l o v e r , d r y i n g  crop i s d i f f i c u l t and t h i s , c o u p l e d w i t h t h e f a c t i t i s  a s h o r t l i v e d s p e c i e s , i n d i c a t e d t h a t c o n s i d e r a t i o n s o t h e r than y i e l d o r quality  must be accounted  f o r before  forage  r e c c o m e n d a t i o n s a r e made.  The f o l l o w i n g g e n e r a l c o n c l u s i o n was based on t h e a s s u m p t i o n t h a t the f o r a g e crop b e i n g h a r v e s t e d was i n t e n d e d as f e e d f o r beef cows. this  study,  largest occur  i t was  variation  from y e a r  species, with  concluded  that  yield  and t h a t , o v e r a l l ,  to year,  t h e next  t h e parameter  w i t h the  the l a r g e s t v a r i a t i o n s i n y i e l d  l a r g e s t between t y p e s , t h e n between  the l e a s t d i f f e r e n c e i n y i e l d  within a species.  was  From  o c c u r r i n g between v a r i e t i e s  The d i f f e r e n c e s i n q u a l i t y parameters between t y p e s ,  s p e c i e s , v a r i e t i e s , hay mixes o r h a r v e s t s was n o t as g r e a t and y i e l d be t h e most for  significant  f a c t o r determining  the production  will  of n u t r i e n t s  c a t t l e p r o d u c t i o n from a g i v e n a r e a o f l a n d . T h e r e f o r e , when a beef c a t t l e p r o d u c e r  or forage mixture  was d e c i d i n g on what  t o grow f o r w i n t e r f e e d , he s h o u l d s e l e c t t h e s p e c i e s  and v a r i e t y w i t h t h e h i g h e s t y i e l d over s e v e r a l y e a r s n u t r i e n t s per hectare variation. producer obtain  harvest  the highest  t o o b t a i n t h e most  o f l a n d and t o reduce t h e impact o f y e a r  In addition to selecting  must  forage  h i s crop  level  the highest y i e l d i n g  forages, the  a t the c o r r e c t phenological  of useable  n u t r i e n t s - i n t h e case  s t u d y , t h e e a r l y t o mid bloom stage o f t h e legume component.  to year  stage of  to this  CHAPTER 6 RECOMMENDATIONS S e v e r a l recommendations f o l l o w from t h i s  study.  Recommendation 1 I t i s recommended t h a t v a r i e t y t e s t i n g c o n t i n u e s i n c e t h e r e can be differences  i n quality  and y i e l d  parameters between v a r i e t i e s  as was  shown w i t h r e d c l o v e r .  Recommendation 2 It  is  recommended  that  management  practices  such  as  harvest  p r o c e d u r e s , s t o r a g e methods, f e r t i l i z a t i o n and i r r i g a t i o n t e c h n i q u e s a l s o be  investigated  factors  i n conjunction with  can a f f e c t  livestock.  the y i e l d  and  variety quality  trials. of  forages  Each  these  harvested f o r  T h e r e f o r e , f o r a g e e v a l u a t i o n i s n o t complete u n t i l  c o n s i d e r a t i o n s are taken i n t o  of  management  account.  Recommendation 3 R e s e a r c h must c o n t i n u e i n o r d e r t o p r o v i d e b e t t e r i n t e r p r e t a t i o n o f existing  forage  techniques particular, needed.  laboratory  evaluation  techniques  or  to provide  so more e f f i c i e n t use o f r e s e a r c h r e s o u r c e s may be made. a technique  f o r more a c c u r a t e l y e s t i m a t i n g f e e d  new In  intake i s  REFERENCES A d e r i b i g b e , A.O., Church, D.C., F r a k e s , R.V., and P e t e r s e n , R.G. 1982. F a c t o r s d e t e r m i n i n g p a l a t a b i l i t y o f r y e g r a s s t o c a t t l e . J . Anim. S c i . 54: 164-172. A e r t s , J.V., De Brabander, D.L., C o t t e n , B.G. and Buysse, F.X. 1977. Comparison o f l a b o r a t o r y methods f o r p r e d i c t i n g t h e o r g a n i c m a t t e r d i g e s t i b i l i t y o f f o r a g e s . Anim. Feed S c i . and Tech. 2: 337-349. A k i n , D.E. 1982. 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N.Z. J . A g r . Res. 19:41-46.  r  APPENDIX 1  CLIMATE OF THE ENGEN AREA  Climate Factor  Month Year  May  June  July  August  1981 1982 1983  238.3 248.0 272.3  240.2 363.0 147.8  317.3 236.6 193.0  304.2 236.4 251.1  Precipitation (mm)  1981 1982 1983  36.0 25.7 13.3  56.7 14.9 67.5  22.4 70.8 86.1  18.2 57.6 40.8  Temperature (°C)  1981 1982 1983  11.6 9.5 12.5  11.6 17.3 12.9  16.9 16.8 15.3  17.4 14.4 15.2  GGD™  1981 1982 1983  205 140 233  198 369 237  369 366 319  384 291 316  Sunshine (Hours)  Total For Growing Season 864.7 1084.0 864.2 133.3 169.0 207.7  1156 1166 1105  11 Temperature and p r e c i p i t a t i o n d a t a a r e from Vanderhoof and s u n s h i n e d a t a a r e from F o r t St.James. UK GGD = Growing Degree Days ( e s t i m a t e d from t h e monthly mean temperature).  

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