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Amino acid supplementation of Peace River barley for growing-finishing pigs Chung, An Sik 1973

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C I  AMINO ACID SUPPLEMENTATION OF PEACE RIVER BARLEY FOR GROWING-FINISHING PIGS  by  AN SIK CHUNG B.S.A., Kon-kuk U n i v e r s i t y , 1966  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n the Department of ANIMAL SCIENCE  We accept t h i s t h e s i s as conforming t o the required standard  THE UNIVERSITY OF BRITISH COLUMBIA March, 1973  In presenting t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the  require-  ments f o r an advanced degree at the U n i v e r s i t y o f B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study. I f u r t h e r agree that permission f o r extensive  copying o f t h i s t h e s i s f o r  s c h o l a r l y purposes may be granted by the Head o f my Department o r by h i s representatives.  I t i s understood that copying o r p u b l i c a t i o n o f t h i s t h e s i s  f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n permission.  Department o f  Animal Science  The U n i v e r s i t y o f B r i t i s h Columbia Vancouver 8, Canada  Date  M^e^J  <?J ^  /fyS  ABSTRACT  The work reported i n t h i s t h e s i s comprised two s e c t i o n s , each o f which compared s i x r a t i o n s i n pigs i n the body weight range 16-85 kg. A l l r a t i o n s were based on barley.  A supplement o f L - l y s i n e HC1 was added  t o provide a t o t a l l y s i n e content o f 0.90% and,0.75%, w i t h the l a t t e r l e v e l a l s o t e s t e d w i t h 0.05% added L-threonine, alone o r w i t h 0.10% DLmethionine o r 0.10% DL-methionine plus 0.10% L - i s o l e u c i n e .  A control  r a t i o n consisted e s s e n t i a l l y o f b a r l e y and soybean meal t o provide 0.75% t o t a l lysine.  These r a t i o n s were used f o r growth and nitrogen balance  experiments. The supplementation o f b a r l e y w i t h 0.50% L - l y s i n e HC1 (0.75% t o t a l l y s i n e ) tended t o improve nitrogen u t i l i z a t i o n more than a supplemental l e v e l o f 0.69% L - l y s i n e HC1 (0.90% t o t a l l y s i n e ) .  The b i o l o g i c a l value  of the r a t i o n containing the lower l e v e l o f l y s i n e was s i g n i f i c a n t l y higher than t h a t o f the r a t i o n containing the higher l e v e l o f l y s i n e , which was r e f l e c t e d i n a trend i n d i c a t i n g t h a t pigs f e d the lower l e v e l of l y s i n e were leaner and had l a r g e r eye muscle areas than those fed the higher l e v e l o f l y s i n e . Adding 0.05% L-threonine t o the lower l e v e l o f l y s i n e improved growth performance but not carcass q u a l i t y . The a d d i t i o n o f L - l y s i n e and L-threonine t o the b a r l e y tended t o improve nitrogen balance above t h a t obtained by the a d d i t i o n o f L - l y s i n e alone.  The f u r t h e r a d d i t i o n o f 0.10%  DL-methionine w i t h o r without 0.10% L - i s o l e u c i n e d i d not improve growth performance but gave a f u r t h e r s l i g h t n o n - s i g n i f i c a n t improvement i n nitrogen metabolism measurements.  Therefore, both the feeding experiment  and n i t r o g e n balance experiment i n d i c a t e d that threonine was the second l i m i t i n g amino a c i d a f t e r l y s i n e . Supplementation o f b a r l e y w i t h amino acids regardless o f l e v e l s o r combinations, gave s i g n i f i c a n t l y poorer d a i l y g a i n , feed e f f i c i e n c y and carcass q u a l i t y r e s u l t s but s i g n i f i c a n t l y higher b i o l o g i c a l value f i g u r e s than the barley-soybean c o n t r o l r a t i o n .  Thus, i t would appear t h a t the  amino acid-supplemented r a t i o n s s t i l l were d e f i c i e n t i n some way, although the b i o l o g i c a l value data would tend t o c o n t r a d i c t the suggestion t h a t t h i s i s associated w i t h an amino a c i d imbalance.  TABLE OF CONTENTS Page ACKNOWLEDGEMENTS LIST OF TABLES  i i  LIST OF FIGURES  I. II.  i  i i i  INTRODUCTION  1  REVIEW OF LITERATURE  2  A.  ESSENTIAL AMINO ACIDS AND NONESSENTIAL AMINO ACIDS  2  B.  AVAILABILITY OF AMINO ACIDS IN THE RATION  3  C.  AMINO ACID DEFICIENCY, EXCESS AND INTERACTION  5  D.  METHODS OF DETERMINING AMINO ACID REQUIREMENT  7  E.  THE USE OF AMINO ACIDS IN PIG NUTRITION  F.  AMINO ACID REQUIREMENT FOR GROWING-FINISHING PIGS  11  13  a.  The Requirement f o r Lysine  14  b.  The Requirement f o r Methionine  16  c.  The Requirement f o r Tryptophan  18  d.  The Requirement f o r Threonine  19  e.  The Requirement f o r Isoleucine  . 20  G.  SUPPLEMENTATION WITH AMINO ACIDS OF GRAIN-PROTEIN  H.  CONCENTRATE RATIONS AND GRAIN ONLY FACTORS AFFECTING AMINO ACIDS SUPPLEMENTATION OF FEEDS  25  a.  Energy Content o f the Rations  25  b.  P r o t e i n Content o f the Rations  28  21  c.  III.  Age and Sex o f the Species Consuming the Rations EXPERIMENT I  31 33  A.  EXPERIMENTAL PROCEDURE  33  a.  33  General  Page b.  Animals  33  c.  Rations  34  d.  Management  34  (i)  Housing '  34  Feeding and Watering  35  Feed Storage and M i x i n g  35  (ii) (iii)  IV.  e.  Records  35  f.  Chemical A n a l y s i s  35  g.  Carcass Measurements  36  h.  Calculations  37  i.  S t a t i s t i c a l A n a l y s i s o f Data  37  B.  RESULTS  41  C.  DISCUSSION  45  D.  CONCLUSION  48  EXPERIMENT I I  59  A.  EXPERIMENTAL PROCEDURE  59  a.  General  59  b.  Animals  59  c.  Rations  59  d.  Management  59  (i) (ii) (iii)  V. VI.  Housing  59  Feeding and Watering  60  M i x i n g Rations  60  e.  Feces and Urine C o l l e c t i o n  60  f.  S t a t i s t i c a l A n a l y s i s o f Data  61  B. . RESULTS  64  C.  DISCUSSION  67  D.  CONCLUSION  71  GENERAL CONCLUSIONS AND RECOMMENDATIONS  73  APPENDIX  86  i ACKMOWL£TJGEMENT  The w r i t e r wishes t o express h i s g r a t i t u d e t o Dr. R.M. Beames o f the Department o f Animal Science f o r h i s constant encouragement and guidance throughout the course o f t h i s study. Thanks are a l s o extended t o Dr. W.D. K i t t s , Chairman o f the Department o f Animal Science, f o r the use o f necessary f a c i l i t i e s f o r t h i s study. I a l s o wish t o express my g r a t i t u d e t o Mrs. L. Mather f o r her assistance i n c a r r y i n g out the amino a c i d analyses.  LIST OF TABLES  i i  Table I. II.  Page Composition o f r a t i o n s used i n Experiments I and I I  .....  38  Content o f e s s e n t a i l amino acids and proximate constituents o f b a r l e y and soybean meal on a dry matter b a s i s  III.  39  Content o f e s s e n t a i l amino acids o f each r a t i o n (g amino acid/lOOg mixed feed) on an a i r - d r y b a s i s  IV.  40  Summary o f e f f e c t s o f the a d d i t i o n o f amino acids t o b a r l e y on body weight g a i n , feed consumption, feed conversion r a t i o and carcass measurements i n the feeding trial  V.  43  Comparison o f the e f f e c t s o f supplementation w i t h amino acids on d a i l y weight gains and carcass measurements o f g i l t s and barrows  VI.  44  A l l o c a t i o n o f pigs w i t h i n r e p l i c a t e s and periods f o r Experiment I I  VII.  62  Summary o f the e f f e c t s o f supplementation o f b a r l e y w i t h amino a c i d on apparent dry matter d i g e s t i b i l i t y , n i t r o g e n balance, apparent nitrogen d i g e s t i b i l i t y , and on nitrogen r e t a i n e d as a percentage o f n i t r o g e n i n t a k e , and as a percentage o f nitrogen absorbed (average 7-day f i g u r e s )  ...  66  LIST OF FIGURES Figure  I.  i i i Page  The e f f e c t o f supplementation w i t h l y s i n e and threonine o f a b a r l e y r a t i o n (Treatment 4) compared t o a barley-soybean c o n t r o l r a t i o n (Treatment 1) on mean body weight from the s t a r t u n t i l f i r s t pigs sent f o r slaughter  II.  ,  55  The e f f e c t o f supplementation w i t h the h i g h e r l e v e l o f l y s i n e (Treatment.2) and the lower l e v e l o f l y s i n e (Treatment 3) on mean weight gain from s t a r t u n t i l f i r s t pigs sent f o r slaughter  III.  56  The e f f e c t o f supplementation w i t h the h i g h e r l e v e l o f l y s i n e (Treatment 2 ) , the lower l e v e l o f l y s i n e (Treatment 3 ) , l y s i n e plus threonine (Treatment 4) and soybean c o n t r o l r a t i o n (Treatment 1) on feed e f f i c i e n c y r a t i o from s t a r t u n t i l f i r s t pigs sent  IV. V.  f o r slaughter  57  General view o f the metabolism cage  63  P i g shown i n the cage which could be adjusted f o r the s i z e o f the p i g  63  1 I.  INTRODUCTION  I t i s w e l l known t h a t c e r e a l p r o t e i n has a low n u t r i t i o n a l value, p r i m a r i l y due t o a r e l a t i v e l y low l e v e l o f the e s s e n t i a l amino a c i d s , l y s i n e , methionine, threonine, tryptophan and i s o l e u c i n e . P i g r a t i o n s are normally based on these c e r e a l s .  I t i s therefore necessary t h a t a supplement provide  adequate l e v e l s o f these l i m i t i n g amino a c i d s . T r a d i t i o n a l l y , the p r o t e i n o f g r a i n i s supplemented w i t h high q u a l i t y p r o t e i n meal o f p l a n t o r animal o r i g i n t o increase the t o t a l p r o t e i n content and t o counteract any e s s e n t i a l amino a c i d d e f i c i e n c y i n the b a s a l r a t i o n o f the growing p i g .  The t o t a l o r p a r t i a l replacement o f p r o t e i n  supplement by s y n t h e t i c amino acids could reduce the cost o f a r a t i o n . The importance o f the l y s i n e content o f the d i e t i s w e l l establ i s h e d and there are many examples i n the l i t e r a t u r e o f the improvement i n performance t h a t can be brought about by l y s i n e supplementation rations.  of cereal  I t has been reported that supplementing c e r e a l mixtures w i t h  l y s i n e , threonine, tryptophan and i n some experiments a l s o w i t h i s o l e u c i n e r e s u l t s i n performance equal t o that obtained w i t h r a t i o n s o f g r a i n plus p r o t e i n concentrates. The present study was undertaken t o examine the e f f e c t s o f adding two l e v e l s o f l y s i n e w i t h o r without threonine, methionine and i s o l e u c i n e t o a b a s a l r a t i o n o f Peace R i v e r b a r l e y i n terms o f d a i l y gain, feed conversion e f f e c i e n c y , carcass q u a l i t y and nitrogen balance.  2 II. A.  REVIEW OF LITERATURE  ESSENTIAL AMINO ACIDS AND NONESSENTIAL AMINO ACIDS  Amino a c i d supplementation of feeds i s based on the r e s u l t s of over s i x t y years o f research on the n u t r i t i o n a l q u a l i t y of p r o t e i n s and t h e i r c o n s t i t u e n t amino acids.  Much of the fundamental work was c a r r i e d  out by Osborne and Mendel (1919, 1920) who studied the growth-promoting q u a l i t i e s of i s o l a t e d p r o t e i n s and recognized that s p e c i f i c amino acids were missing o r present i n low concentrations i n those p r o t e i n s which d i d not support adequate growth of the animal.  Rose. (1938) d i v i d e d the amino  acids found i n p r o t e i n s i n t o two main c a t e g o r i e s , the e s s e n t i a l and the nonessential amino acids.  E s s e n t i a l amino acids are those which cannot  be synthesized by the organism at a r a t e adequate t o meet metabolic requirements and must be supplied i n the d i e t .  Nonessential i s the term a p p l i e d  t o those andno acids which the body can synthesize from normal food cons t i t u e n t s v i a transamination r e a c t i o n s .  I t should be emphasized t h a t t h i s  c l a s s i f i c a t i o n i s based on growth studies i n the r a t (Rose 1938).  Class-  i f i c a t i o n o f the amino acids w i t h respect t o t h e i r growth e f f e c t i n the white r a t are given below.  Glycine i s not e s s e n t i a l f o r the growing p i g  but i s e s s e n t i a l f o r the growing chick.  The requirement f o r arginine and  g l y c i n e appears more acute i n the more r a p i d l y f e a t h e r i n g breeds o f b i r d s (Hegsted e t a l . 1941). ESSENTIAL Arginine* Histidine Isoleucine Leucine Lysine *  Methionine Phenylalanine Threonine ' Tryptophan Valine  NONESSENTIAL Alanine Aspartic acid Citrulline Cystine Glutamic a c i d Glycine  Hydroxy glutamic a c i d Hydroxy p r o l i n e Norleucine Proline Serine Tyrosine  Arginine can be synthesized by the r a t but not at a s u f f i c i e n t l y r a p i d r a t e t o meet the demands of normal growth.  3 The proportion of e s s e n t i a l amino acids provided by various proteins i s the major f a c t o r i n f l u e n c i n g the b i o l o g i c a l value.  The  f a i l u r e of young animals t o grow on a d i e t d e f i c i e n t i n one o r more o f the e s s e n t i a l amino acids i s a r e f l e c t i o n of i t s i n a b i l i t y t o synthesize adequate q u a n t i t i e s of body p r o t e i n under these experimental conditions. The r e s u l t of an amino a c i d d e f i c i e n c y i n the d i e t i s t h a t the t i s s u e s do not synthesize p r o t e i n r e q u i r i n g t h a t p a r t i c u l a r amino a c i d . The terms e s s e n t i a l and nonessential r e l a t e mainly t o d i e t a r y requirements and have l i t t l e meaning w i t h respect t o the r e l a t i v e importance which amino acids may have i n metabolism.  The amino acids which  are e s s e n t i a l i n the d i e t are compounds w i t h carbon skeletons which can not r e a d i l y be synthesized by the body.  In a r e a l sense, the s o - c a l l e d  n o n e s s e n t i a l amino acids are of equal s i g n i f i c a n c e f o r the economy of the organism which i s p a r t i c i p a t i n g i n diverse c e l l u l a r reactions and f u n c t i o n s , and provide precursors f o r the synthesis o f many important c e l l u l a r c o n s t i tuents.  Indeed, c e r t a i n o f the nonessential amino a c i d s , e.g.,  glutamic  a c i d , have so many important metabolic r o l e s t h a t , were a mammal t o lose suddenly i t s capacity t o synthesize glutamic a c i d , serious d i s o r g a n i z a t i o n of key r e a c t i o n s o f metabolism might r e s u l t as the animal may be unable t o wait u n t i l the next meal t o r e p l e n i s h i t s supply. B.  AVAILABILITY OF AMINO ACID IN THE RATION  I t has been stressed t h a t the content o f amino acids i n a p r o t e i n may not a c c u r a t e l y r e f l e c t i t s n u t r i t i v e value, since some o f the amino acids may not be a v a i l a b l e to synthesize the t i s s u e of the animal. Problems involved i n determining a v a i l a b i l i t y o f amino acids have been discussed. by Grau and C a r r o l l (1958).  A considerable number o f b i o l o g i c a l and a few  chemical procedures have been developed.  A s a t i s f a c t o r y chemical procedure  4 f o r measuring l y s i n e a v a i l a b i l i t y has been described by Carpenter (1960) which depends upon the r e a c t i o n o f dinitroflurobenzene w i t h the e-amino group o f l y s i n e .  The r e a c t i o n produces a colored l y s i n e d e r i v a t i v e and  i t can, t h e r e f o r e , be used t o estimate the l y s i n e w i t h the f r e e e-amino group.  The r e s u l t s obtained w i t h animal p r o t e i n s c o r r e l a t e c l o s e l y w i t h  gross p r o t e i n value determined i n the chick under conditions where the l y s i n e content of the m a t e r i a l s i s emphasized.  With vegetable p r o t e i n  and high carbohydrate d i e t s , the method i s not as s a t i s f a c t o r y , the f i g ures obtained being too low because o f the d e s t r u c t i o n of the colored l y s i n e d e r i v a t i v e . Moran e t a l . (1963) used the r e a c t i o n of the  dye  Orange G w i t h b a s i c amino acids t o determine the a v a i l a b i l i t y of f r e e amino, amidazole, and guanidyl group o f p r o t e i n s .  The dye b i n d i n g capac-  i t y o f soybean meal heated f o r varying periods of time was c l o s e l y r e l a t e d to growth o f chicks fed the meal. The most widely used b i o l o g i c a l procedures f o r determining a v a i l a b i l i t y o f amino a c i d are those based on growth of r a t s (Calhoun et a l . 1960).  In t h i s method, increments of the pure amino a c i d t o be  tested are added t o a b a s a l d i e t d e f i c i e n t i n the amino a c i d and a growth response curve i s obtained.  The response found w i t h protein-bound amino  acids i s then compared w i t h t h a t obtained w i t h the pure amino a c i d t o determine a v a i l a b i l i t y .  Oh e t a l . (1972) determined b i o l o g i c a l a v a i l a b i l i t y  o f methionine i n various p r o t e i n supplements.  Four procedures of bioassay  were studied on the b a s i s of slope-ratio.^technique: (a) weight gain versus l e v e l s o f d i e t a r y methionine;  (b) e f f i c i e n c y of feed u t i l i z a t i o n  versus  l e v e l s o f d i e t a r y methionine;  (c) weight gain versus t o t a l a v a i l a b l e  methionine consumed; and (d) gain i n weight a t t r i b u t a b l e t o intake o f t e s t p r o t e i n methionine versus methionine intake from the t e s t p r o t e i n .  5 Method (d) was the most precise and r e l i a b l e method as judged by the usual s t a t i s t i c a l c r i t e r i a .  Using t h i s method ,the a v a i l a b l e methionine  content o f meat, f i s h , blood, rapeseed, soybean and feather meal was estimated t o be 91.1, 89.9,  66.3,  87.2, 94.7 and 35.0% r e s p e c t i v e l y .  Nielson (1971) showed that the d i g e s t i b i l i t y o f amino acids from d i f f e r e n t balanced r a t i o n s was r e l a t e d t o the d i g e s t i b i l i t y o f n i t r o gen i n growing p i g s .  The r e s u l t s i n d i c a t e d that the d i g e s t i b i l i t y o f  l y s i n e was not s i g n i f i c a n t l y d i f f e r e n t from the d i g e s t i b i l i t y o f nitrogen. Lower d i g e s t i b i l i t y c o e f f i c i e n t s were found f o r methionine, threonine and a l a n i n e , whereas the d i g e s t i b i l i t y c o e f f i c i e n t s f o r c y s t i n e , v a l i n e , l e u c i n e , i s o l e u c i n e , phenylalanine, t y r o s i n e , h i s t i d i n e , a r g i n i n e , glutamic a c i d and a s p a r t i c a c i d were higher than f o r nitrogen. There i s much v a r i a t i o n i n amino a c i d a v a i l a b i l i t y from various p r o t e i n supplements.  Amino a c i d contents should be l i s t e d as a v a i l a b l e  amino a c i d r a t h e r than t o t a l .  However, i t i s d i f f i c u l t t o show a v a i l a b l e  f i g u r e s because a v a i l a b i l i t y o f amino acids i n many r a t i o n components v a r i e s from batch t o batch, and the method o f determining amino a c i d a v a i l a b i l i t y i s d i f f i c u l t and time consuming. C.  AMINO ACID DEFICIENCY, EXCESSES AND INTERACTION  D e f i c i e n c i e s , i n t e r a c t i o n s and excesses can reduce growth r a t e although excesses generally have t o be a t higher l e v e l s than those found i n normal r a t i o n s before they i n t e r f e r e with growth. The question o f amino a c i d imbalance and antagonism has a r i s e n f a i r l y recently.  To e x p l a i n the term imbalance i t might be appropriate  t o give the d e f i n i t i o n o f a well-balanced p r o t e i n , which i s "a p r o t e i n i n which the e s s e n t i a l amino acids occur i n i d e a l proportions,  and are  thus required i n minimal q u a n t i t i e s t o s a t i s f y the amino a c i d requirements  of the animal". Amino a c i d imbalance may be defined as a depression i n growth (or any other adverse e f f e c t ) which r e s u l t s from an a l t e r a t i o n o f amino a c i d balance o f the r a t i o n , produced by adding a mixture o f amino acids o r a p r o t e i n t h a t lacks one o f the e s s e n t i a l amino acids.  The  adverse e f f e c t can be counteracted by feeding a small supplement o f the most l i m i t i n g amino a c i d .  For example, Harper (1959) mentioned t h a t when  g e l a t i n i s added t o a casein d i e t , growth may decrease unless tryptothan i s a l s o added.  I t i s t y p i c a l o f an imbalance t h a t the requirement f o r  the most l i m i t i n g amino a c i d i s increased.  Antagonism i s described as an  excess o f a s i n g l e amino a c i d t h a t may cause a growth depression and r e s u l t i n an increased need f o r one o r more o f the other amino acids. o f leucine causes an increase i n the requirement f o r i s o l e u c i n e .  An excess This  r e c o g n i t i o n i s based upon the observation t h a t d i e t a r y additions of incomp l e t e mixtures o f amino acids cause a severe growth depression which i s prevented by supplementation o f the d i e t w i t h the amino acids that are most l i m i t i n g (Harper 1958;  Deshpande e t a l . 1958).  I n three papers by D'Mello and Lewis (1970 a, b, c ) , evidence has been presented t o demonstrate the unique i n t e r a c t i o n between l y s i n e and a r g i n i n e , between l e u c i n e , i s o l e u c i n e and v a l i n e * and between threonine and tryptophan i n the chick.  The r e s u l t s i n d i c a t e t h a t excess d i e t a r y  l y s i n e increases the arginine requirement o f the young c h i c k , and excess threonine increases tryptophan requirement q u a n t i t a t i v e l y , while excess leucine increases the q u a n t i t i e s of i s o l e u c i n e and v a l i n e r e q u i r e d t o s u s t a i n normal growth.  The r e s u l t s o f these experiments permit the general  conclusion t h a t the requirements o f amino acids are interdependent.  The  unique i n t e r a c t i o n between l y s i n e and a r g i n i n e i n chick n u t r i t i o n supports the observations o f other authors (O'Dell e t a l . 1958;  Jones 1964;  Smith  7 and Lewis 1966).  The i n t e r a c t i o n s between l e u c i n e , i s o l e u c i n e and v a l i n e  a l s o have been observed i n experiments with r a t s (Harper e t a l . 1954; Benton et a l . 1956;  Rogers e t a l . 1967).  The i n t e r a c t i o n or i n t e r r e l a t i o n -  ship between threonine and tryptophan has been known t o occur i n the r a t (Salmon 1954;  Morrison e t al.. 1960; D.  F l o r e n t i n o e t a l . 1962).  METHOD OF DETERMINING AMINO ACID REQUIREMENT  Determination o f the n u t r i t i o n a l value of p r o t e i n i s i n h e r e n t l y non-specific.  In the case of vitamins or e s s e n t i a l minerals, one  evaluate a s i n g l e e s s e n t i a l n u t r i e n t at a time.  Conversely, i n the assay  of p r o t e i n value, one must be concerned with, the q u a l i t a t i v e and t a t i v e adequacy o f at l e a s t nine amino acids. o f amino a c i d balance and u t i l i z a t i o n t o be  can  quanti-  There are also problems considered.  I t i s i n e v i t a b l e that d i f f e r e n t assay methods w i l l d i f f e r i n the c l a s s i f i c a t i o n o f proteins as t o n u t r i t i v e value. methods have d i f f e r i n g parameters of measurement.  The d i f f e r e n t assay  Despite the  vagaries  inherent i n assay procedures, i t i s of i n t e r e s t t o note that most methods have c l a s s i f i e d most food proteins i n the same general order o f adequacy. The balanced, p r o t e i n s of meat, m i l k and eggs have been used as standards o f excellence.  The major g r a i n proteins are low i n one or more e s s e n t i a l  amino acids and are generally improved i n feeding value by amino a c i d f o r t i f i c a t i o n .  appropriate  Balance can a l s o be achieved, as i n the case  of manufactured feeds f o r p o u l t r y and swine, by f o r t i f i c a t i o n w i t h a s i n g l e p r o t e i n source such as soybean meal. The approximate amino a c i d needs of s e v e r a l species are known. By a knowledge of the e s s e n t i a l amino a c i d composition of a p r o t e i n , one can p r e d i c t i t s feeding value w i t h a f a i r degree of accuracy.  One  cannot  p r e d i c t , however, i n e f f i c i e n c i e s i n d i g e s t i b i l i t y or the e f f e c t s of pro-  8 c e s s i n g , which are not g e n e r a l l y revealed by composition analyses.  Protein  evaluation methods, which r e f l e c t true feeding v a l u e , continue, t h e r e f o r e , t o provide the ultimate i n b i o l o g i c a l e v a l u a t i o n .  I n d i r e c t methods o f  p r o t e i n e v a l u a t i o n confirm and complement the d i r e c t feeding methods. Most of the experimental work r e f e r r e d t o i n t h i s review has been c a r r i e d out on the growing animal, mostly w i t h an ad l i b i t u m feeding regime.  Growth r a t e , feed conversion and i n many cases carcass q u a l i t y  have acted as the c r i t e r i a i n p i g production f o r the e v a l u a t i o n of r a t i o n adequacy.  The performance and carcass q u a l i t y o f pigs are i n f l u e n c e d not  only by the q u a l i t y o f the d i e t , but a l s o by the system of feeding. Clausen et a l . (195.9-1964)' i n t r i a l s w i t h amino a c i d s , have used both ad l i b i t u m feeding and r e s t r i c t e d feeding.  An i n t e r p r e t a t i o n of t h e i r  •results i s t h a t the response t o both treatments has been about the same. I t i s recommended that any program f o r the e v a l u a t i o n o f amino amino a c i d supplementation growth o f an animal.  include an evaluation of the e f f e c t on the  Carcass measurements have i n some cases added v a l -  uable information i n growth experiments.  Backfat t h i c k n e s s , eye muscle  area and f a t - l e a n r a t i o are a l l c o r r e l a t e d t o the percentage of lean (or p r o t e i n ) i n the c a r c a s s , w i t h a c o r r e l a t i o n c o e f f i c i e n t of about (Clausen et a l . 1959-1964;  0.7  Marcum et a l . 1961).  Although performance i s important i n p r a c t i c a l animal production, weight gain i s an inaccurate c r i t e r i o n o f nitrogen r e t e n t i o n .  Nitrogen  balance values are o f much greater value i n assessing p r o t e i n q u a l i t y . The concept o f " b i o l o g i c a l value" was f i r s t introduced by Thomas (1909) i n terms o f percent- o f d i g e s t i b l e nitrogen from a t e s t food which was r e t a i n e d by the human a d u l t .  M i t c h e l l e t a l . (1945) brought the method  t o a greater s t a t e of p r e c i s i o n by using the growing r a t .  Biological  9 value i s a d i r e c t measure o f the proportion o f d i e t a r y p r o t e i n which can be u t i l i z e d by body t i s s u e s and may be defined as the percentage o f the absorbed n i t r o g e n which i s r e t a i n e d by the animal.  A balance t r i a l i s  conducted i n which nitrogen intake and u r i n a r y and f e c a l excretions o f n i t r o g e n are measured.  The r e s u l t s are used t o c a l c u l a t e the b i o l o g i c a l  value as f o l l o w s : n B  „ V  N i n t a k e - ( F e c a l N + Urinary N) =  !  AT  •  -4-  i  =5  n—M  , 1  X  0  n n 0  N intake-Fecal N The metabolic f e c a l n i t r o g e n and the endogenous u r i n a r y nitrogen are not d i r e c t l y derived from immediate d i e t a r y nitrogen.  The existence i n both  feces and urine o f nitrogen f r a c t i o n s , the e x c r e t i o n o f which i s independent o f d i e t a r y n i t r o g e n , i s most convincingly demonstrated by the f a c t t h a t some nitrogen i s excreted when the animal i s given a n i t r o g e n free d i e t . R y  The r e v i s e d formula i s N i n t a k e - ( F e c a l N-MFN)-(Urinary N-EUN) N i n t a k e - ( F e c a l N-MFN)  ,  n n  X  where MFN = metabolic f e c a l n i t r o g e n and EUN = endogenous u r i n a r y nitrogen. In determining b i o l o g i c a l value, the greatest amount p o s s i b l e of the d i e t a r y p r o t e i n should be provided by the p r o t e i n under t e s t . P r o t e i n intake must be s u f f i c i e n t t o a l l o w adequate n i t r o g e n r e t e n t i o n , but must not be i n excess o f t h a t required f o r maximum r e t e n t i o n ; i f the l a t t e r l e v e l were exceeded,the r e s u l t i n g general amino a c i d catabolism would depress the estimate o f b i o l o g i c a l value.  For t h i s reason, s u f f i c i e n t  non-nitrogenous n u t r i e n t s must be given t o prevent catabolism o f p r o t e i n t o provide energy. The amino a c i d mixture absorbed by the animal i s r e q u i r e d f o r the synthesis o f body p r o t e i n s .  The e f f i c i e n c y w i t h which t h i s synthesis  can be e f f e c t e d depends p a r t l y on how c l o s e l y the amino a c i d proportions o f the absorbed mixture resemble those o f body p r o t e i n s , and p a r t l y on  10 the extent t o which these proportions can be modified.  The b i o l o g i c a l  value o f a food p r o t e i n depends upon the number and k i n d o f amino acids present i n the molecule.  Since e s s e n t i a l amino acids cannot be e f f e c -  r i v e l y synthesized i n the animal body, an imbalance o f these i n the d i e t leads t o a wastage.  Food p r o t e i n w i t h a d e f i c i e n c y o f any p a r t i c u l a r  e s s e n t i a l amino a c i d w i l l tend t o have a low b i o l o g i c a l value. Since b i o l o g i c a l value i s dependent p r i m a r i l y upon e s s e n t i a l amino a c i d make-up, i t would seem l o g i c a l to' assess the n u t r i t i v e value of a p r o t e i n by a q u a n t i t a t i v e estimation o f i t s e s s e n t i a l amino a c i d c o n s t i t u t i o n and then compare t h i s w i t h the known amino a c i d requirement of a p a r t i c u l a r c l a s s o f animal. To overcome the economic problems associated w i t h b i o l o g i c a l methods f o r d e s c r i b i n g p r o t e i n q u a l i t y , two schemes have been proposed, both o f which a r r i v e a t a numerical value f o r q u a l i t y by considering the r e l a t i v e amount o f the amino acids present i n the p r o t e i n as determined by chemical ( o r i n some cases b i o l o g i c a l ) a n a l y s i s . Block and M i t c h e l l (1946) suggested that poor p r o t e i n q u a l i t y was caused p r i m a r i l y by a r e l a t i v e shortage o f some one e s s e n t i a l amino acid.  They took the composition o f whole egg p r o t e i n as the standard o r  i d e a l , and determined the percentage by which the amino a c i d i n greatest d e f i c i t was considered l i m i t i n g .  The complement o f the percentage d e f i c i t  o f t h i s amino a c i d was the chemical score given t o t h a t p r o t e i n .  Such  values c o r r e l a t e w e l l w i t h the b i o l o g i c a l values f o r the r a t and human beings but not f o r p o u l t r y .  They are u s e f u l f o r grouping proteins  into  c a t e g o r i e s , but s u f f e r a serious disadvantage i n t h a t no account i s taken of the d e f i c i e n c i e s o f amino acids other than the amino a c i d i n greatest deficit.  11 Oser (1951), although approving the general p r i n c i p l e o f chemical score as o u t l i n e d by Block and M i t c h e l l (1946), i n d i c a t e d t h a t a l l essent i a l amino acids should be considered r a t h e r than the one which i s most d e f i c i e n t w i t h respect t o some standard.  He developed the e s s e n t i a l amino  a c i d index which may be defined as the geometric mean o f the e s s e n t i a l amino acids when each i s expressed as a percentage o f the l e v e l o f the same amino a c i d i n egg p r o t e i n and i s c a l c u l a t e d as ^..-r where  a, b, c,  _ n/-100a . 100b , 100c , / ae be ce  , 100J je ,  ... j = percentage o f the e s s e n t i a l amino a c i d s i n the  food p r o t e i n , ae, be, c e , ... j e = percentage o f the same e s s e n t i a l amino acids i n egg p r o t e i n , and n = the number o f amino acids e n t e r i n g i n t o the calculation. The index has the advantage o f p r e d i c t i n g the e f f e c t s o f supplement a t i o n i n combinations o f p r o t e i n s .  I t has the disadvantage t h a t p r o t e i n s  o f very d i f f e r e n t amino a c i d composition may have the same o r a very s i m i l a r index. E.  THE USE OF AMINO ACIDS IN PIG NUTRITION  In the 1930's the ten amino acids e s s e n t i a l f o r promoting normal growth i n the r a t were v e r i f i e d (Rose 1938), and i n the 1940's the q u a n t i t a t i v e requirements o f the 12 ajirino acids needed i n c h i c k growth were v i r t u a l l y established.  The f i r s t serious attempt t o f i n d the requirements  f o r amino acids i n p i g n u t r i t i o n was probably made by Beeson e t a l .  (1948,  1949), who used a p u r i f i e d r a t i o n i n combination w i t h hydrolyzed f i s h p r o t e i n f o r young p i g s .  The r a t i o n was p r a c t i c a l l y tryptophan-free (0.01%).  A d d i t i o n o f 0.4% DL-tryptophan caused a marked response i n growth r a t e , as the c o n t r o l p i g s had no weight gain and pigs f e d tryptophan gained 634 g a day during a four-week p e r i o d . This c l e a r l y demonstrates the  12 s i g n i f i c a n c e o f tryptophan i n the r a t i o n o f the growing pig. continued by Beeson and h i s associates at Purdue.  Work was  More p r e c i s e than the  f i r s t attempt was the next experiment, where graded levels- o f DL-tryptophan from 0.1 t o 0.4 were added t o the b a s a l d i e t containing 0.01% tryptophan (Shelton 1951a).  In t h i s case z e i n and g e l a t i n were used i n the b a s a l  d i e t , which contained 24.5% p r o t e i n . per  Although there were only two pigs  treatment, the r e s u l t s were very c o n s i s t a n t , 0.2% DL-tryptophan being  s u f f i c i e n t f o r normal growth.  At the same time as the Purdue group (Beeson  et a l . 1948, Mertz e t a l . 1949; Beeson e t a l . 1953, Mertz e t a l . 1955) were i n v e s t i g a t i n g the requirements f o r other amino a c i d s , L o o s l i and h i s coworkers at C o r n e l l ( B e l l e t a l . 1950; Brinegar e t a l . 1950a and 1950b; Kroening e t a l . 1962) performed,extensive studies along the same l i n e s . The t h i r d group o f workers t h a t has done much work i n e v a l u a t i n g the quant i t a t i v e needs o f amino acids i n the growing p i g s , i s Becker and h i s associates at I l l i n o i s (Becker e t a l . 1955; Becker, 1959 and Becker e t a l . 1963).  Several other s c i e n t i s t have a l s o c a r r i e d out such studies.  In  recent y e a r s , f o r i n s t a n c e , comprehensive experiments have been undertaken at Cambridge (Evans, 1958, 1960, 1962, 1963) and i n Copenhagen (Clausen et a l .  1959-1964). Most experiments have been done on weanling pigs (eight weeks  o l d ) , but s u c k l i n g pigs have a l s o been used t o some extent.  The method  frequently used i s t o make up a b a s a l r a t i o n of p u r i f i e d carbohydrate-rich ingredients plus a p r o t e i n t h a t i s d e f i c i e n t i n one o r more o f the n a t u r a l l y o c c u r r i n g amino acids.  I t has not been too d i f f i c u l t t o f i n d p r o t e i n low  i n tryptophan (hydrolyzed feather meal, z e i n , g e l a t i n ) , l y s i n e ( z e i n , l i n seed meal, wheat p r o t e i n ) , i s o l e u c i n e (blood f l o u r ) , methionine ( e x p e l l e r soybean meal) and threonine ( i s o l a t e d soybean p r o t e i n , r i c e p r o t e i n ) .  If  13 the p r o t e i n used i s a poor source o f other amino acids i n a d d i t i o n t o the one i n question, a proper supplement o f the others must be given.  The  s c a r c i t y of proteins d e f i c i e n t i n the amino acids not mentioned above has l i m i t e d the use o f t h i s  technique.  Consequently, a d i e t w i t h a l l t e n e s s e n t i a l amino acids ( f o r the r a t ) as the sole source o f n i t r o g e n , except ammonium c i t r a t e , was s u c c e s s f u l l y developed as e a r l y as 1950 by Shelton e t a l . f o r weanling pigs.  Experiments w i t h a d d i t i o n o f one o r more amino a c i d s . t o p r a c t i c a l  type d i e t s have a l s o been b e n e f i c i a l t o our present knowledge of the quant i t a t i v e requirement o f the d i f f e r e n t amino acids (Clausen e t a l . 19591964).  Another approach t o the problem was proposed by C u r t i n e t a l . (1952c).  This was based on amino a c i d composition o f the carcasses o f the p i g s . The l y s i n e requirement, e s t a b l i s h e d e a r l i e r , was used as the b a s i s while the requirement o f the other e s s e n t i a l amino acids was e s t a b l i s h e d i n proportion t o the content o f l y s i n e i n the body.  Studying the amino a c i d  content o f pigs a t various ages, D u r t i n e t a l . (1952c) found a s u r p r i s i n g l y constant l e v e l o f the i n d i v i d u a l amino a c i d s , when they were expressed i n percentagesof the t o t a l p r o t e i n i n the body.  I n 1952 Mertz e t a l . concluded,  on the b a s i s o f t h e i r own experiments as w e l l as those o f others, t h a t the growing p i g , l i k e the growing r a t , needs t e n amino acids.  The p i g a l s o  resembles the r a t i n the a b i l i t y t o synthesize p a r t , but not a l l o f the arginine required f o r normal growth and performance. F.  AMINO ACID REQUIREMENT FOR GROWING-FINISHING PIGS  I t has been known f o r many years t h a t the p r o t e i n requirement o f animals can be stated more p r e c i s e l y i n terms o f amino a c i d requirements. Pigs r e q u i r e f o r normal growth t e n e s s e n t i a l amino a c i d s .  Also they should  be given a d d i t i o n a l nitrogen so t h a t t h e i r bodies can synthesize the non-  14 e s s e n t i a l amino acids.  Amino a c i d .needs increase as p r o t e i n l e v e l and  c a l o r i c d e n s i t y increase (Bowland 1962; Becker e t a l . 1963; VanLoen 1966). Hence, some c a l c u l a t i o n s and i n t e r p o l a t i o n s are required (Becker e t a l . 1963; VanLoen 1966). a.  The Requirement f o r Lysine. Mertz e t a l . (1949) were the f i r s t t o o f f e r experimental evidence  t h a t l y s i n e was an e s s e n t i a l f a c t o r i n the growing p i g . Brinegar e t a l . (1949) concluded t h a t 0.58% l y s i n e was the requirement of weanling pigs when the p r o t e i n content o f the r a t i o n was 10.6%.  In l a t e r studies ( B r i n -  egar e t a l . 1950a,b), a b a s a l r a t i o n containing 22% p r o t e i n was f e d t o weanling pigs and the growth data showed a requirement o f 1.20%  lysine.  According t o these studies there seemed t o e x i s t a p r o p o r t i o n a l i t y between the l y s i n e requirement o f 5.5% - 5.7% o f the d i e t a r y p r o t e i n when the prot e i n content ranged from 10.6 - 22%, meaning t h a t the growing animal's l y s i n e requirement could be stated as a percentage o f the t o t a l d i e t a r y protein.  McWard e t a l . (1959) found t h a t the requirement o f l y s i n e i n a  12.8% p r o t e i n d i e t was 0.71% and i n the 21.7% p r o t e i n r a t i o n , 0.95%. Change e t a l . (1958) f a i l e d t o achieve consistent r e s u l t s .  In  one experiment the l y s i n e requirement, expressed as a percentage of the d i e t , was not influenced by the p r o t e i n l e v e l , while i n a second experiment they found a l y s i n e requirement o f 0.7% when the r a t i o n contained 10 or 15% p r o t e i n , and 0.9% w i t h a r a t i o n o f 20% p r o t e i n .  Becker (1959) a r r i v e d  at the c o n c l u s i o n , based on chick and p i g experiments, t h a t the r e q u i r e ment o f each amino a c i d i s l i n e a r , but not p r o p o r t i o n a l l y r e l a t e d t o the p r o t e i n content o f the r a t i o n . His recommended allowances o f amino acids i n the n u t r i t i o n o f weanling pigs are given f o r seven d i f f e r e n t p r o t e i n l e v e l s , varying from 12 t o 24% p r o t e i n i n the dry r a t i o n . The need f o r  15 each amino a c i d , expressed as a percentage o f the t o t a l d i e t a r y  protein,  i s assumed t o decrease by a c e r t a i n percentage as the p r o t e i n l e v e l o f r a t i o n i s increased.  Most o f the l y s i n e work mentioned above points t o -  ward a requirement i n weanling pigs o f about 0.6 - 0.7% o f the r a t i o n when the t o t a l d i e t a r y p r o t e i n content i s 12 - 15%. Becker (1963) recommends 0.74% l y s i n e f o r weanling pigs fed a 16% p r o t e i n r a t i o n . I t i s suggested by the I l l i n o i s workers t h a t c a l o r i c density of the r a t i o n may a l s o influence the amino a c i d requirement.  This can  p a r t l y be hidden by the f a c t t h a t the pigs eat more o f a d i e t low i n c a l o r i e s than o f a d i e t o f high c a l o r i c density  (McWard e t a l . 1959).  This p o i n t has e a r l i e r been stressed by Sewell e t a l . (1956) and Abernathy e t a l . (1958), but i s h a r d l y c l e a r enough t o j u s t i f y a d e f i n i t e  conclusion.  B e l l e t a l . (1968) concluded t h a t the l y s i n e requirement f o r 23 t o 57 kg pigs f e d a r a t i o n containing 0.7%.  3,330 k c a l . d i g e s t i b l e energy/kg was about  Evidence concerning the l y s i n e and p r o t e i n requirement of f i n i s h i n g  pigs (57 - 90 kg approximately) l i k e w i s e remains c o n t r o v e r s i a l .  B e l l (1965)  demonstrated that-by increasing the d i e t a r y l y s i n e l e v e l from 0.55 t o 0.67% was as e f f e c t i v e as increasing the p r o t e i n l e v e l from 13 t o 16%, when the response c r i t e r i a were growth rate and e f f i c i e n c y of feed u t i l i z a t i o n . The reverse was the case when i n d i c e s o f lean meat content were assessed. The B r i t i s h A.R.C. p u b l i c a t i o n (1967) suggested that young pigs would give s a t i s f a c t o r y performance i f , up t o about 50 kg l i v e w e i g h t , the d i e t contains about 0.75 - 0.8% l y s i n e and t h e r e a f t e r about 0.6 - 0.65% (0.9 - 0.95 and 0.7 - 0.75% o f the dry matter i n the d i e t  respectively)  compared w i t h the N.A.S. - N.R.C. (1968) recommendation o f 0.7% t o 20 35 kg pigs and 0.5% f o r f i n i s h i n g pigs.  16 b.  The Requirement f o r Methionine. B e l l e t a l . (1950) demonstrated the need f o r methionine i n swine  rations.  C u r t i n (1952a, 1952b, 1952c) using soybean plus p u r i f i e d d i e t s  containing 22% p r o t e i n as feed f o r weanling p i g s , found no improvement i n growth r a t e , feed conversion or n i t r o g e n balance by adding DL-methionine. He stated that the requirement d i d not exceed 0.31% methionine, when the c y s t i n e content was 0.38%.  Shelton (1951a) used o x i d i z e d c a s e i n , g e l a t i n  and tryptophan as amino a c i d sources i n a p u r i f i e d d i e t t o which an animalprotein-factor-supplement, l i v e r e x t r a c t , and choline were a l s o added. Using weanling pigs i n growth s t u d i e s , they concluded t h a t the methionine requirement i n the absence of c y s t i n e amounted t o 0.60%, but the need of S-containing amino acids could a l s o be met by using 0.30% methionine plus 0.30% c y s t i n e .  Using weanling p i g s , graded l e v e l s o f DL-methionine  and  L-cytine were added t o a p u r i f i e d r a t i o n containing 12% i s o l a t e d soybean protein.  Becker e t a l . (1955) concluded t h a t a l e v e l o f 0.25% methionine  i n the presence o f 0.17% c y s t i n e supported a s a t i s f a c t o r y r a t e o f growth. Expressed as a percentage of the d i e t a r y p r o t e i n , the combined methionine + c y s t i n e requirment was c a l c u l a t e d t o be 3.33%.  Cystine can apparently  provide about 40% o f the need f o r S-bearing amino a c i d s . A considerable proportion o f the t r i a l s conducted t o determine the methionine requirement o f pigs have been c a r r i e d out w i t h corn-soybean meal r a t i o n s .  However, the method f o r e x t r a c t i n g the o i l meal i s relevant  as the heat treatment w i l l i n f l u e n c e p r o t e i n q u a l i t y (Becker e t a l . 1953). This may a t l e a s t be one of the explanations f o r the experiments on supplementation of methionine t o soybean meal r a t i o n s having f a i l e d t o give consistent r e s u l t s .  There may be other f a c t o r s .  Berry e t a l . (1962) have  shown t h a t methionine i s d e f i n i t e l y the f i r s t l i m i t i n g amino a c i d i n soy-  17 bean meal, as might be expected from the amino a c i d composition.  In  t h e i r experiment w i t h soybean meal added t o a p u r i f i e d r a t i o n , a s i g n i f i cant growth-promoting value was found by adding methionine.  As the grains  are a l s o r e l a t i v e l y poor sources of methionine, one could expect a response i n the growth r a t e o f pigs when adding methionine t o a grain-soybean meal ration.  Experimental evidence f o r t h i s has been produced by some workers  ( B e l l e t a l . 1950; Pfander e t a l . 1953;  Bayley e t a l . 1968), while others  have reported no growth response (Catron e t a l . 1953; Arcker e t a l . 1959; et a l .  Change e t a l . 1960;  Sewell e t a l .  1958;  Beames e t a l . 1969; Oestemer  1970). Other r a t h e r commonly used p r o t e i n feeds, such as peanut meal,  cottonseed meal and sesame meal, have about the same methionine content as soybean meal.  In some cases (Whitehair e t a l . 1952), a d d i t i o n of DL-  methionine t o r a t i o n s containing these meals as p r o t e i n concentrates has improved feed u t i l i z a t i o n . Becker e t a l . (1966) i n d i c a t e d a requirement o f 0.50% methionine + c y s t i n e f o r growing p i g s w i t h an i n i t i a l weight of 20 kg f e d a d i e t cont a i n i n g 16% p r o t e i n ; they a l s o i n d i c a t e d t h a t c y s t i n e could supply 40% o f the t o t a l need f o r the s u l f u r bearing amino acids.  The N.A.S.-N.R.C.  (1968) i n d i c a t e d a methionine requirement o f 0.50% o f the d i e t f o r pigs i n the weight range 20 - 30 kg.  Oestemer e t a l . (1970) suggested t h a t the  methionine + c y s t i n e requirement of growing pigs from 21 t o about 40 kg was somewhat l e s s than the f i g u r e o f 0.42% t o 0.50% o f the d i e t as reported by i n v e s t i g a t o r s previous c i t e d .  These t r i a l s were conducted i n a s e r i e s  of experiments w i t h growing swine t o determine the capacity o f opaque-2 corn t o provide adequate d i e t a r y methionine.  The corn r a t i o n s (crude  p r o t e i n 10.85%) contained 0.275, 0.279, 0.227% methionine + c y s t i n e . N e i t h e r  18 r a t e o f g a i n , gain/feed nor p r o t e i n evaluation r a t i o (PER) was s i g n i f i c a n t l y improved by supplementing the b a s a l corn d i e t w i t h 0.07, 0.14, 0.21 o r 0.28% DL-methionine. K e i t h e t a l . (1972) i n d i c a t e d t h a t when Yorkshire g i l t s averagi n g 18 k g body weight were f e d a s e m i p u r i f i e d d i e t containing s i x graded l e v e l s o f methionine during s i x 4-day feeding p e r i o d s , p l o t t i n g serum methionine concentration against d i e t a r y methionine intake showed t h a t the methionine requirement was 0.46% o f the r a t i o n .  This estimate was  substantiated by animal performance data (protein 18.39%). H i l l (1965) has pointed out t h a t methionine and cystine are l a r g e l y destroyed by h y d r o c h l o r i c a c i d during a c i d h y d r o l y s i s and must, therefore,.be converted t o stable d e r i v a t i v e s . I f methionine and c y s t i n e were under-estimated i n the b a s a l r a t i o n o r c e r e a l d i e t as the r e s u l t o f d e s t r u c t i o n 'by a c i d , t h e i r c a l c u l a t e d requirement would be v a r i a b l e . Therefore, the method used i n determining the amino a c i d contents i n various experiments should be taken i n t o account when i n t e r p r e t i n g r e s u l t s , c.  The Requirement o f Tryptophan. Beeson e t a l . (1948, 1949) were the f i r s t t o i n v e s t i g a t e the  need f o r tryptophan.  Shelton e t a l . (1951b) working w i t h weanling p i g s ,  used a p u r i f i e d 24.5% p r o t e i n r a t i o n containing z e i n and g e l a t i n plus some amino a c i d s .  They concluded t h a t the growing p i g needed 0.2% tryptophan  i n the d i e t or. 0.8% o f the t o t a l d i e t a r y p r o t e i n .  By adding graded l e v e l s  t o a b a s a l r a t i o n w i t h 0.09% tryptophan (17% p r o t e i n ) , the Purdue workers found an optimum supplement o f 0.06% DL-tryptophan.  The requirement was  set a t 0.12% L-tryptophan, considering L-tryptophan as the only form t o be u t i l i z e d .  The f i n d i n g t h a t tryptophan can be converted i n t o n i a c i n i n  pigs (Luecke e t a l . 1946) and confirmed by Powick e t a l . (1948) i s con-  19 sidered important i n corn r a t i o n s , as the corn i s a very poor source o f available niacin.  Becker e t a l . (1954a) suggested 0.13% tryptophan t o  be adequate f o r weanling pigs.  This agrees w i t h n i t r o g e n balance studies  made by Meade (1956), s t a r t i n g w i t h p i g s o f 32 kg liveweight and using a 15.9% p r o t e i n corn-soybean meal r a t i o n .  I n t h i s t r i a l n i a c i n was added  t o the b a s a l r a t i o n . The A.R.C. (1967) suggests t h a t 0.15% t o 0.20% L-tryptophan i n the dry matter i n the d i e t should be adequate i n the presence o f adequate amounts o f n i c o t i n i c a c i d .  The N.A.S.-N.R.C. (1968) recommends t h a t 0.13%  tryptophan i s adequate f o r growing pigs weighing 20 - 35 kg and t h a t the l e v e l can be reduced t o 0.09% f o r f i n i s h i n g p i g s , d.  The Requirement f o r Threonine. The threonine requirement has been studied i n weanling pigs by  Shelton e t a l . (1950c), and i n s u c k l i n g pigs by Sewell e t a l . (1952), using p u r i f i e d o r s e m i - p u r i f i e d d i e t s i n c l u d i n g c a s e i n and washed i s o l a t e d soybean p r o t e i n .  I n a r e p o r t from I l l i n o i s (Berry e t a l . 1962) i t i s  suggested t h a t the p r o t e i n i n soybean meal has threonine as the t h i r d l i m i t i n g amino a c i d ( a f t e r methionine and l y s i n e ) .  Experimental evidence  (Berry e t a l . 1962) w i t h r a t s and p i g s i n d i c a t e s that threonine might be second l i m i t i n g and l y s i n e t h i r d .  Beeson e t a l . (1953) gave young p i g s  a d i e t based on corn and i n c l u d i n g nine e s s e n t i a l amino acids.  The d i e t  provided 13.2% p r o t e i n and 0.2% threonine. When a supplement o f L-threonine was g i v e n , maximum weight gain and best feed conversion e f f i c i e n c y were w i t h 0.4% d i e t a r y threonine (3.0% o f the d i e t a r y crude p r o t e i n ) .  Mertz  e t a l . (1952) a l s o estimated the requirement o f L-threonine t o be 0.4% o f the d i e t .  With p r o v i d i n g 12% C P . based on d r i e d skim m i l k , Becker e t a l .  (1954b) c a l c u l a t e d t h a t 0.61% L-threonine was a s a t i s f a c t o r y d i e t a r y con-  20 centration.  These workers c a l c u l a t e d the threonine content o f a d i e t which  had produced s a t i s f a c t o r y growth, so t h a t t h e i r estimate o f requirement might w e l l be excessive. I n a s i m i l a r way, Evans (1958) c a l c u l a t e d the threonine content o f d i e t s which had been proven t o give s a t i s f a c t o r y performance, namely d i e t s c o n t a i n i n g e i t h e r 7% f i s h meal, 20% ground nut meal, o r 15% soybean meal, t o be 0.52, 0.55 and 0.55% r e s p e c t i v e l y .  I n f u r t h e r experimental  work, the same author (1963) gave a d i e t c o n t a i n i n g 6% soybean meal, supplemented w i t h l y s i n e and methionine which provided 0.43% threonine t o pigs up t o 36 kg l i v e w e i g h t and obtained a s i g n i f i c a n t response i n terms of growth r a t e and feed conversion e f f i c i e n c y when a supplement o f 0.15% L-threonine was added. Robinson e t a l . (1963) f e d an a l l - c e r e a l d i e t supplemented w i t h l y s i n e and methionine, and p r o v i d i n g 0.46% threonine was supplemented w i t h i s o l e u c i n e , threonine and tryptophan and a s i g n i f i c a n t improvement i n performance was noted.  An a p p r a i s a l o f these data, however, i n d i c a t e s t h a t  the response was more probably due t o the i s o l e u c i n e and/or the tryptophan, since these amino acids were more severely d e f i c i e n t w i t h respect t o assumed requirements. The A.R.C. (1967) suggests t h a t the requirement f o r L-threonine f o r weanling pigs i s about 0.45 - 0.5% o f the r a t i o n (0.5 - 0.6%':of the dry matter i n the r a t i o n ) .  This compares w e l l w i t h the l e v e l o f 0.45% f o r  growing pigs given by the N.A.S.-N.R.C. e.  (1968).  The Requirement f o r I s o l e u c i n e . Brinegar e t a l . (1950c) f e d a s e m i - p u r i f i e d d i e t o f s t a r c h ,  glucose, blood f l o u r and DL-methionine t o growing p i g s .  Maximum weight  gain (630 g/day) was obtained when L - i s o l e u c i n e was added t o give a l e v e l  21  o f 0.7% o f the r a t i o n equal to. 3.2% o f the t o t a l d i e t a r y p r o t e i n .  Becker  e t a l . (1963) reported t h a t pigs weighing-5 kg required 0.76% d i e t a r y i s o l e u c i n e , 3.45% o f the d i e t a r y p r o t e i n , while pigs weighing 45 kg required 0.35%  d i e t a r y i s o l e u c i n e , 2.63% o f the d i e t a r y p r o t e i n . Bravo e t a l . (1970) reported t h a t pigs weighing from 20 - 40 kg  require from 0.27 t o 0.32% i s o l e u c i n e i n the d i e t when average d a i l y g a i n , feed conversion r a t i o and l e v e l s o f plasma free i s o l e u c i n e were the response criteria.  Using p r a c t i c a l type r a t i o n s , Evans (1962) found no improvement  e i t h e r i n growth o r nitrogen r e t e n t i o n from the a d d i t i o n o f i s o l e u c i n e t o a d i e t containing 0.59% i s o l e u c i n e . The A.R.C. (1967) suggests t h a t 0.65% L - i s o l e u c i n e i n the d i e t (0.75% o f the dry matter i n the d i e t ) i s adequate f o r pigs between 14 and 45 kg liveweight and t h a t the requirement might w e l l be l e s s f o r pigs o f over 45 kg liveweight.  This compares w i t h a recommendation o f 0.5% f o r  pigs weighing 20 - 35. kg by N.A.S.-N.R.C. (1968). G.  SUPPLEMENTATION WITH AMINO ACID OF GRAIN-PROTEIN CONCENTRATE RATIONS AND GRAIN ONLY.  For p i g d i e t s normally based on c e r e a l s , p r o t e i n  concentrates  are added t o increase the t o t a l p r o t e i n content and t o counteract any e s s e n t i a l amino a c i d d e f i c i e n c i e s i n the b a s a l r a t i o n . The importance o f the l y s i n e content o f the r a t i o n i s w e l l e s t a b l i s h e d and there are many examples i n the l i t e r a t u r e showing the improvement i n performance t h a t can be brought about by l y s i n e supplementation o f r a t i o n s containing p o o r - q u a l i t y p r o t e i n (Evans 1960; Jones e t a l . 1962; Rozman e t a l . 1968; Ostrowski 1969; Braude e t a l . 1972).  I t has a l s o been reported that a  small improvement i n performance can be obtained when l y s i n e i s added t o d i e t s containing white f i s h meal, but economic a p p r a i s a l o f the r e s u l t s  22 showed t h a t t h i s was not a v i a b l e p r o p o s i t i o n a t p r e v a i l i n g p r i c e s (Braude and Lerman 1970).  However, the greatest use o f l y s i n e and other  amino acids as supplements may l i e i n the p o s s i b l e replacement o f p r o t e i n r  concentrates, since the l a t t e r are by f a r the most expensive d i e t a r y components.  I t has been reported t h a t the feeding o f c e r e a l mixtures sup-  plemented w i t h l y s i n e , threonine, tryptophan, methionine and i n some experiments a l s o i s o l e u c i n e , r e s u l t s i n performance equal t o t h a t obtained w i t h r a t i o n s c o n t a i n i n g p r o t e i n concentrates (Robinson and Lewis 1963; MUller e t a l .  1967b).  Weanling p i g s were f e d a c e r e a l d i e t w i t h d i f f e r e n t  supplements  of amino a c i d s . The c e r e a l d i e t c o n s i s t e d o f wheat, b a r l e y and oats.  The  t r i a l was conducted from 14 - 18 kg body weight t o 50 kg body weight. The combination o f l y s i n e and threonine had a marked e f f e c t upon gains and feed conversion.  Supplementing w i t h l y s i n e alone enhanced gains i n one  case by 19% and i n another case by 21%.  The combination of l y s i n e and  threonine increased gains by 59% i n the f i r s t t r i a l and by 92% i n the second t r i a l .  Feed conversion improved by 31 - 34%. I n the combination  of l y s i n e and tryptophan, 0.02% added tryptophan showed a p o s i t i v e i n f l u e n c e , whereas a tryptophan a d d i t i o n o f 0.04% caused a depression i n a l l t r i a l s . The supplement o f l y s i n e alone increased weight gain by 26 - 28%, whereas the combination o f l y s i n e and tryptophan increased gain by 35 - 42%. I n t r i a l s w i t h a combination o f two methionine l e v e l s and l y s i n e , a s l i g h t increase was recorded i n comparison w i t h a supplement o f l y s i n e alone. How^ ever, d i f f e r e n c e s were not s t a t i s t i c a l l y s i g n i f i c a n t .  A supplement o f  0.03% methionine gave b e t t e r r e s u l t s than a supplement o f 0.05% methionine (MUller e t a l . 1967a).  I t appears t h a t threonine and tryptophan are both  equal as the second l i m i t i n g amino acids.  23 Since the report by Jensen e t a l . (1965) on g r a i n plus amino a c i d d i e t s , there has been considerable e f f o r t put i n t o f i n d i n g n u t r i t i o n a l l y adequate and econimical r a t i o n s using these two ingredients as the major components.  From a s e r i e s o f papers (Muller and MaMk 1967a, 1967b, 1967c;  M i l l e r e t a l . 1967a, 1967b, 1967c; 1968)  M u l l e r and Rozman 1968; Rozman e t a l .  i t i s evident that Czechoslovakian s c i e n t i s t s are g r e a t l y i n t e r e s t e d  i n t h i s type o f r a t i o n . In the paper by Jensen e t a l . (1965) i t was reasoned on the b a s i s o f the U n i v e r s i t y o f I l l i n o i s feeding standards (Becker e t a l . 1963) that l y s i n e and p o s s i b l y methionine were a l l that were r e q u i r e d as a supplement t o sorghum f o r pigs from 45 t o 90 kg body weight, whereas l y s i n e and t r y p tophan were the required amino acids t o supplement com.  Their r e s u l t s  showed a growth response t o the a d d i t i o n o f 0.25% l y s i n e t o sorghum g r a i n but no response t o the f u r t h e r a d d i t i o n o f methionine.  In a similar experi-  ment reported by Beames e t a l . (1968) up t o 0.2% l y s i n e improved growth r a t e and feed e f f i c i e n c y o f f a t t e n i n g p i g s , but the improvement i n carcass q u a l i t y was s l i g h t .  E r i c s o n e t a l . (1962) a l s o improved growth r a t e and  feed e f f i c i e n c y i n a wheat barley-amino a c i d r a t i o n f e d from 32 kg body weight t o 90 kg w i t h l y s i n e added t o the g r a i n t o a l e v e l of 0.86% o f the ration. In the supplementation o f s e v e r a l g r a i n - p r o t e i n concentrate r a t i o n s w i t h amino a c i d s , responses have been obtained t o incremental increases o f l y s i n e up t o l e v e l s i n excess o f most o f the suggested r e q u i r e ments (Ericson e t a l . 1962), but even though such supplemented d i e t s have often given - sub-optimal performance, the f u r t h e r a d d i t i o n o f methionine g e n e r a l l y gives no response (Jensen e t a l . 1965; Beames and Pepper 1969). Optimal growth and feed e f f i c i e n c y , however, were obtained by M u l l e r and  24  Rozman (1968) w i t h maize, b a r l e y and wheat when each was supplemented w i t h l y s i n e (0.41 - 0.61%), threonine (0.1 - 0.27%), tryptophan (0.04 - 0.15%) and methionine (0.14 - 0.25%) from weanling p i g s o f 30 kg body weight and w i t h reduced l e v e l s t h e r e a f t e r . Cystine can s a t i s f y 40 percent o f the need f o r methionine (N.A.S — N.R.C. 1968).  Although the methionine + cystine requirements o f growing  pigs are widely taken as being 0.5 - 0.6% o f the r a t i o n , there are some experiments which i n d i c a t e that 0.3 - 0.42% i s adequate f o r optimal growth (Beames and Pepper 1969; Oestemer e t al._ 1970).  I t could be suggested  that l a c k o f response t o methionine supplementation under some circumstances was due t o other f a c t o r s i n the r a t i o n being l i m i t i n g .  However, the r e s u l t  o f Oestemer e t a l . (1970) would tend t o r e f u t e t h i s as they obtained good performance w i t h a t o t a l methionine + c y s t i n e l e v e l o f 0.23 - 0.28% o f the ration. Berry e t a l . (1966), using corn-soybean and corn-sugar-soybean d i e t s , found that the response t o supplementation w i t h l y s i n e and methionine depended on the a d d i t i o n o f threonine, i n d i c a t i n g t h a t t h i s amino a c i d i s l i m i t i n g i n low p r o t e i n , corn-soybean meal d i e t s . Pecora and Hundley (1951) obtained a large improvement i n growth rate o f r a t s f e d r i c e by supplementing the d i e t w i t h l y s i n e and threonine. Sure (1954) demonstrated that wheat and rye were d e f i c i e n t i n l y s i n e and threonine and f u r t h e r , t h a t rye was d e f i c i e n t i n v a l i n e .  Pond e t a l .  (1958)  i n d i c a t e d t h a t l y s i n e and threonine were probably the most l i m i t i n g amino acids i n milo f o r growth and t h a t the l i v e r f a t content o f r a t s r e c e i v i n g the b a s a l r a t i o n was s i g n i f i c a n t l y reduced by a d d i t i o n o f 0.5% L - l y s i n e and 0.2% DL-threonine.  Rosenberg e t a l . (1959) e s t a b l i s h e d l y s i n e and threonine  as the f i r s t and second l i m i t i n g amino acids i n r i c e p r o t e i n f o r  25  the growth o f the weanling r a t . Methionine, i s o l e u c i n e and tryptophan were next l i m i t i n g amino acids i n t h i s order. P i c k e t a l . (1971) showed t h a t e x c e l l e n t d a i l y g a i n , gain/feed and p r o t e i n e f f i c i e n c y r a t i o (nitrogen r e t e n t i o n ) could be obtained when a d i e t c o n t a i n i n g 89.5% opaque-2 was supplemented w i t h 0.1% L - i s o l e u c i n e , 0.18 t o 0.35% L - l y s i n e , 0.2% DL-methionine, 0.12% L-phenylalanine, 0.14% L-threonine and 0.08% L - v a l i n e . F i n a l d i e t a r y l e v e l s o f 0.36% i s o l e u c i n e , 0.7% l y s i n e o r l e s s , 0.40% methionine + c y s t i n e , 0.59. t o 0.65% phenylalanine + t y r o s i n e , 0.43% threonine and 0.54% v a l i n e appeared t o be adequate f o r the growing r a t . H. a.  FACTORS AFFECTING AMINO ACIDS SUPPLEMENTATION OF FEEDS  Energy Content o f the Ration. I t has long been r e a l i z e d t h a t a p r o t e i n can be u t i l i z e d a t  maximum e f f i c i e n c y only i f there i s s u f f i c i e n t energy i n the d i e t from nonprotein sources t o s a t i s f y the requirement o f the organism f o r c a l o r i e s . That the a v a i l a b l e energy i n a d i e t can be o f c r i t i c a l  importance  f o r the s u c c e s s f u l amino a c i d supplementation o f animal feeds was not r e a l i z e d u n t i l a d i r e c t r e l a t i o n s h i p between the energy and p r o t e i n content was demonstrated i n b r o i l e r feeds.  The system f o r expressing the energy  value i s t h a t d i g e s t i b l e o r metabolizable energy are used almost u n i v e r s a l l y f o r p i g s and p o u l t r y . When protein-energy r e l a t i o n s h i p s are considered, i d e a l l y only the completely balanced p o r t i o n o f the p r o t e i n should be c a l culated as p r o t e i n and the r e s t as energy.  Using a corn-soybean meal  d i e t (Rosenberg e t a l . 1955) l i t t l e o r no response was obtained i n the chick when a small amount o f methionine was added t o the r a t i o n i n s p i t e of the f a c t t h a t the f i r s t l i m i t i n g amino a c i d i n the d i e t was considered to be methionine.  However, when f a t was added t o the d i e t the chicks  26  responded t o the supplemental d i e t a r y methionine w i t h improved growth and feed e f f i c i e n c y .  This e f f e c t was  a l s o shown when carbohydrates were  used t o replace the f a t ( B a l d i n i and Rosenberg 1957).  These studies  suggest a d i r e c t r e l a t i o n between c a l o r i c density and the l e v e l o f amino acids necessary i n the d i e t . The combined r e s u l t s of two such experiments ( B a l d i n i and Rosenberg 1955;  B a l d i n i and Rosenberg 1957)  i n d i c a t e d t h a t three d i f f e r e n t  c a l o r i e l e v e l s , 1960, 1985 and 2205 c a l o r i e s of productive energy per kg, required d i f f e r e n t l e v e l s of methionine f o r optimum performance o f chicks. In p o u l t r y , the energy-methionine r e l a t i o n s h i p has been explained on the . b a s i s t h a t b i r d s eat p r i m a r i l y t o s a t i s f y t h e i r energy requirements, although t h e i r food intake i s governed a l s o by a number o f other f a c t o r s i n c l u d i n g p r o t e i n concentration and composition of the p r o t e i n .  When the energy con-  t e n t o f a d i e t i s increased,birds eat l e s s per u n i t o f gain.  An  increase  i n energy content of the d i e t r e s u l t s , t h e r e f o r e , i n an increase i n the e f f i c i e n c y o f feed u t i l i z a t i o n .  An increase o f the f a t content of the d i e t  increases the c a l o r i c density and may  cause a drop i n food intake.  If  p r o t e i n content i s not increased i n a r a t i o n w i t h added f a t , the l e v e l o f p r o t e i n per c a l o r i e i s decreased, r e s u l t i n g i n a f a l l i n p r o t e i n intake even though the c a l o r i e intake may be unchanged.  In b r o i l e r r a t i o n s con-  t a i n i n g d i f f e r e n t l e v e l s of added f a t , t h i s question i s an important one, and has been s t r e s s e d by Waddel (1959).  B a l d i n i e t a l . (1957), Rosenberg  and C u l i k (1955), and Williams and Grau (1956) showed t h a t the c a l o r i c density i s one o f the f a c t o r s governing the amino a c i d requirements o f growing turkeys, r a t s and chicks. Sewell e t a l . (1956), Abernathy e t a l . (1958) and McWard e t a l . (1959) observed that pigs eat more o f a d i e t low i n c a l o r i e s than of a  27  d i e t o f h i g h c a l r o i c density.  Whether o r not a l l o f the supplemented  amino acids - l y s i n e , threonine, methionine, e t c . - needed t o e f f e c t amino a c i d balance can be u t i l i z e d w i l l depend largely, upon the energy content of the d i e t .  This concept o f amino a c i d u t i l i z a t i o n , o f course, does a f f e c t  the way i n which the amino a c i d requirements are formulated, but n a t u r a l l y t h i s c a l l s f o r proper knowledge o f the requirement o f both e s s e n t i a l amino acids and energy. Henry (1968) found t h a t ad l i b i t u m f e d g r o w i n g - f i n i s h i n g pigs achieved maximum energy intake on d i e t s having 3.25 Mcal/kg d i g e s t i b l e energy. Robinson  etlal.  (1964) " concluded t h a t the best growth performance  and carcass lean content o f pigs r e c e i v i n g a d i e t o f low energy content was recorded when the r a t i o o f K c a l D.E. t o kg d i e t a r y l y s i n e was approximately 3500.  A t the higher d i e t a r y energy l e v e l the best performance i n terms o f  carcass q u a l i t y was a l s o recorded a t a s i m i l a r r a t i o o f energy t o l y s i n e . O v e r a l l carcass q u a l i t y was adversely a f f e c t e d by high energy l e v e l s i n the f i n i s h i n g d i e t s but was improved as the p r o t e i n l e v e l was r a i s e d .  The r e s -  ponse o f g i l t s t o i n c r e a s i n g p r o t e i n and l y s i n e l e v e l s i n the d i e t continue beyond the l e v e l where the response i n barrows creases.  Robinson's e x p e r i -  ment showed no s i g n i f i c a n t sex d i f f e r e n c e s i n terms o f liveweight gain o r e f f i c i e n c y o f feed u t i l i z a t i o n but g i l t s were much superior t o barrows i n terms o f carcass q u a l i t y .  With pigs averaging 16 t o 22 kg liveweight i n i -  t i a l l y , the r a t e o f gain and gain/feed r a t i o were i n f l u e n c e d by the d i e t a r y lysine levels.  There was no evidence o f i n t e r a c t i o n between l y s i n e l e v e l  and energy l e v e l o f the d i e t on r a t e of g a i n , but there was a s i g n i f i c a n t i n t e r a c t i o n f o r gain feed r a t i o i n one experiment.  The c a l c u l a t e d l y s i n e  needs, expressed as percentage o f the d i e t , were 0.65, 0.77 and 0.80 f o r  28  maximum r a t e o f g a i n and 0.66, 0.71 and 0.85 f o r maximum feed e f f i c i e n c y i n d i e t s containing 2926, 3267 and 3718 k c a l . ME. p e r kg r e s p e c t i v e l y . These values were equivalent t o an average l y s i n e need i n the d i e t equal to 0.23% p e r 1000 k c a l . ME. ( M i t c h e l l e t al.1965). b.  P r o t e i n Content o f the Ration. One o f the major p o i n t s o f disagreement i n e s t a b l i s h i n g the amino  a c i d requirement i s whether i t should be given as a percentage o f the d i e t or as a percentage o f the t o t a l d i e t a r y p r o t e i n .  Arguments have been pro-  duced f o r the v a l i d i t y o f the concept o f a c e r t a i n percentage o f the d i e t a r y p r o t e i n a t a l l l e v e l s o f p r o t e i n i n the r a t i o n (Brinegar e t a l .  1950a)  while other research work has produced r e s u l t s i n disagreement w i t h t h i s f i n d i n g (Hutchinson e t a l . 1957).  A l t o g e t h e r , much evidence has been pro-  duced i n favor o f the concept t h a t the requirement should be stated as a percentage o f the d i e t , but i n order t o i n t e r p r e t these d a t a . i t i s necessary ;  t h a t the p r o t e i n l e v e l o f the d i e t s be known. Harper (1959), and Harper and Kumta (1959) are o f the opinion t h a t the increase i n the requirement o f an amino a c i d w i t h i n c r e a s i n g prot e i n percentage i s r a t h e r small and o f doubtful s i g n i f i c a n c e over the normal range o f p r o t e i n l e v e l s .  I f the requirement o f an amino a c i d i s expressed  i n percentage o f the t o t a l d i e t a r y p r o t e i n , t h i s percentage w i l l decrease as the p r o t e i n l e v e l o f the r a t i o n i s r a i s e d .  Barnes and Bosshardt (1946)  have emphasized t h a t the i d e a l e v a l u a t i o n o f p r o t e i n should be made a t the l e v e l o f p r o t e i n t h a t gives maximum e f f i c i e n c y i n converting food p r o t e i n to body p r o t e i n .  This p r o t e i n l e v e l w i l l be somewhat lower than the p r o t e i n  allowance recommended f o r farm animals.  The frequently used technique t o  t e s t the supplementation by a c e r t a i n amino a c i d o f a p r a c t i c a l type d i e t at two o r three d i f f e r e n t p r o t e i n l e v e l s around the recommended standard  29  may be a u s e f u l means o f d e t e c t i n g responses both as t o p r o t e i n l e v e l and amino a c i d supplementation at the same time The report o f Grau (1948) i s frequently r e f e r r e d t o i n order t o i l l u s t r a t e the' connection between the requirements o f l y s i n e and p r o t e i n . As the p r o t e i n percentage o f the r a t i o n was increased from 10 t o 30, the c a l c u l a t e d l y s i n e requirement was doubled.  Becker (1963) states that i s o -  leucine and l y s i n e requirements o f p i g s , expressed as a percentage o f the t o t a l d i e t a r y p r o t e i n , decreases w i t h i n c r e a s i n g p r o t e i n l e v e l i n the ration.  Harper (1959) mentions that i f there are two l i m i t i n g f a c t o r s  such as p r o t e i n and l y s i n e , the l y s i n e need w i l l increase u n t i l p r o t e i n , as such, becomes l i m i t i n g . ment.  This i s not a c t u a l l y an increase i n the r e q u i r e -  Harper (1959) adds; "Nevertheless, there does come a p o i n t a t which  i t i s p o s s i b l e t o demonstrate t h a t an adequate d i e t i s made l e s s adequate i f the o v e r a l l p r o t e i n i s increased w h i l e the l e v e l o f one amino a c i d i s h e l d constant". Boomgaardt and Baker (1970, 1971) i n d i c a t e d t h a t the l y s i n e and tryptophan requirements o f young chicks are a constant percentage o f d i e t ary crude p r o t e i n .  Expressed as a percentage o f diet, the requirement  increased l i n e a r l y as d i e t a r y crude p r o t e i n l e v e l increased.  I t was estab-  l i s h e d t h a t the l y s i n e requirement remained constant at 4.59% o f the p r o t e i n , and tryptophan requirement was 0.87% o f the p r o t e i n .  These r e s u l t s w i t h  tryptophan and l y s i n e do not support the generally-accepted concept t h a t the requirement f o r an e s s e n t a i l amino a c i d decreases l i n e a r l y as a percentage o f the p r o t e i n and increases c u r v i l i n e a r l y as a percentage o f the d i e t as d i e t a r y p r o t e i n l e v e l increases from d e f i c i e n c y t o adequacy.  This  experimentally e s t a b l i s h e d r e l a t i o n s h i p may be expressed i n a d i f f e r e n t manner when the r a t i o o f c a l o r i e s t o p r o t e i n i s h e l d constant, the amount  30 of amino acids required by the body f o r best performance and expressed as percent o f p r o t e i n remains r e l a t i v e l y constant when the concentration of p r o t e i n i n the d i e t i s increased.  When the r a t i o o f c a l o r i e s t o pro-  t e i n i s increased,the amino a c i d requirement as a percentage o f p r o t e i n increases a l s o .  When the r a t i o o f c a l o r i e s t o p r o t e i n decreases, the  amino a c i d requirement, as a percentage o f p r o t e i n , decreases (Rosenberg 1959). The e f f e c t o f change i n p r o t e i n l e v e l i s a problem o f considerable p r a c t i c a l importance as feeds f o r domestic animals range from 10% p r o t e i n f o r the f a t t e n i n g p i g t o 30% p r o t e i n f o r the turkey poult (Rosenberg 1959).  Percent p r o t e i n i n the d i e t i s p l o t t e d against percent o f  amino a c i d in. the p r o t e i n f o r l y s i n e , methionine, and the combination o f methionine and c y s t i n e i n corn-soy d i e t s .  As the l e v e l o f p r o t e i n i s  increased, the r e l a t i v e amount o f l y s i n e i n the d i e t i n c r e a s e s , while the relative  amounts o f the s u l f u r - b e a r i n g amino acids decrease.  Therefore,  as the p r o t e i n l e v e l increases, methionine d e f i c i e n c y i s l i k e l y t o occur. Conversely, as the p r o t e i n l e v e l decreases, l y s i n e d e f i c i e n c y i s l i k e l y t o occur (Rosenberg e t a l . 1959).  Lawrence (1971) i n d i c a t e d t h a t b a r l e y  d i e t s , compared w i t h maize d i e t s , gave b e t t e r growth r a t e s and energetic c o n v e r s i o n ' e f f i c i e n c i e s , l i g h t e r carcasses, lower k i l l i n g out percentage and smaller eye muscles. . 1 diets  The narrow c a l o r i e p r o t e i n / l y s i n e (CPL) r a t i o  .  2  when compared w i t h wide CPL r a t i o d i e t s  gave b e t t e r growth rates  and energetic conversion e f f i c i e n c i e s , l i g h t e r c o l d carcass  weights,  smaller b a c k f a t deposits and greater percentage o f lean and bone but smaller percentage o f f a t i n the carcass. 1.  D i g e s t i b l e energy: crude p r o t e i n = 198:1, Crude p r o t e i n : l y s i n e = 19.8:1.  2.  D i g e s t i b l e energy: crude p r o t e i n = 263:1 = 27.6:1 o r 26.9:1.  o r 273:1, crude p r o t e i n : l y s i n e  31 c.  Age and Sex of. the Species Consuming the Rations. The unique functions i n the animal body served by the amino  acids r e s u l t i n g from p r o t e i n d i g e s t i o n are a l l anabolic i n character. They r e l a t e t o the replacement o f e s s e n t i a l t i s s u e constituents t h a t have been degraded i n c a t a b o l i c r e a c t i o n s , o r t o the formation o f new t i s s u e constituents i n growth.  I n t h e r a p i d l y growing animal, the l a t t e r func-  t i o n s dominate the body's requirements f o r amino acids.  I n the mature  animal, the replacement functions may dominate the amino a c i d requirements, but the growth functions s t i l l p e r s i s t , since some t i s s u e s continue t o grow throughout l i f e ( M i t c h e l l 1949).  Among adult animals o f d i f f e r e n t  species, the r e l a t i v e importance o f the growth functions i n determinging amino a c i d requirement w i l l depend mainly on the r a t e o f growth o f the epidermal s t r u c t u r e s , such as h a i r , n a i l s and claws. Species d i f f e r e n c e s i n amino a c i d requirements during growth would be expected not so much on the basis o f d i f f e r e n c e s i n the nature of the anabolic r e a c t i o n s , as on the b a s i s o f d i f f e r e n c e s i n the r a t e o f growth o f new t i s s u e i n comparison w i t h the weight o f t i s s u e t o be maint a i n e d , t h a t i s , the percentage r a t e o f growth.  The h i g h e r the percentage  growth r a t e , the greater the extent t o which the growth o f new t i s s u e dominates the t o t a l amino a c i d requirements ( M i t c h e l l 1959).  I t seems  c l e a r that as f a r as growth r a t e and feed conversion e f f i c i e n c y i n pigs are concerned, the crude p r o t e i n requirements as a percentage o f the d i e t f a l l s w i t h i n c r e a s i n g liveweight.  Considering the p e r i o d up t o about  45 - 50 kg l i v e w e i g h t , the requirement as a percentage o f the dry matter i n the d i e t appears t o be about 16 - 17% crude p r o t e i n , and from 50 kg t o 90 kg liveweight about 13 - 14% crude p r o t e i n .  A.R.C. (1967) i n d i c a t e d  that the presence o f a n t i b i o t i c s reduced the requirement f o r crude p r o t e i n ,  32 at l e a s t as f a r as growth r a t e i s concerned. Less a t t e n t i o n has been p a i d t o a d i f f e r e n c e between sexes w i t h respect t o t h e i r amino a c i d requirements. although t h i s i s r e l a t i v e l y small. 0.65%  A c t u a l l y , there i s a d i f f e r e n c e  Maximum growth was obtained w i t h about  l y s i n e i n the d i e t of male r a t s while only about 0.57%  needed f o r maximum growth of the females.  l y s i n e was  I n t e r e s t i n g l y enough, t h i s  d i f f e r e n c e i n the requirement disappears i f the amount of l y s i n e r e q u i r e d per gram o f gain i s c a l c u l a t e d (Rosenberg and Rohdenberg, 1952). d i f f e r e n c e has been observed i n the growing chick (Rosenber 1959).  A similar Accord-  i n g l y , i t has been proposed t o feed male and female b r o i l e r s and p o u l t s separate d i e t s . Bayley e t a l . (1968) i n d i c a t e d t h a t there was a s i g n f i c i a n t i n t e r a c t i o n between the s t r a i n o f p i g and p r o t e i n l e v e l .  Lacombe and  Yorkshire pigs responded t o an increase i n the d i e t a r y p r o t e i n l e v e l from 13 t o 16% by i n c r e a s i n g g a i n , whereas the crossbred and Landrace pigs d i d not. Smith e t a l . (1967) showed t h a t g i l t s were more responsive t o an improvement i n the l e v e l and type of p r o t e i n than barrows, while Bay l e y e t a l . (1968) i n d i c a t e d t h a t boars were even more responsive than g i l t s t o the adequacy of the p r o t e i n content of the d i e t .  Robinson e t a l . (1964)  i n d i c a t e d t h a t the response of g i l t s continued w i t h i n c r e a s i n g p r o t e i n and l y s i n e l e v e l s i n the d i e t while t h a t of barrows ceased at a much lower level.  This w i l l i n f l u e n c e the l e v e l o f l y s i n e o r other amino acids t o  be recommended and w i l l be d i f f e r e n t f o r barrows and g i l t s .  Robinson (1964)  therefore concluded no s i g n i f i c a n t sex d i f f e r e n c e s i n terms o f liveweight gain o r e f f i c i e n c y o f feed u t i l i z a t i o n but g i l t s were superior t o barrows i n terms o f carcass q u a l i t y .  33  III. A.  EXPERIMENT I •  EXPERIMENTAL PROCEDURE  a. General. P r o t e i n i s one o f the more c o s t l y n u t r i e n t s i n p r a c t i c a l swine rations.  Barley i s the most common energy source f o r Western Canadian  swine growers, while soybean meal i s widely used as a p r o t e i n source. Consequently, swine r a t i o n s generally include these two f e e d s t u f f s as major i n g r e d i e n t s .  I n t h i s experiment, b a r l e y and soybean meal were the  sole major ingredients i n the c o n t r o l r a t i o n . Swine do not require p r o t e i n p e r se but require the contained amino acids f o r the synthesis o f body t i s s u e .  The e s s e n t i a l amino acids  f o r optimum growth o f swine which are generally d e f i c i e n t i n b a r l e y according t o N.A.S.-N.R.C. (1968) recommendations are l y s i n e , threonine, methionine and i s o l e u c i n e .  The f o l l o w i n g experiment was designed t o study the  e f f e c t o f supplementation o f Peace R i v e r b a r l e y w i t h two l e v e l s o f l y s i n e i n combination w i t h threonine, methionine and i s o l e u c i n e on the performance of growing-finishing p i g s . The experimental design consisted o f s i x treatments w i t h three replications.  Each o f the s i x treatments w i t h i n r e p l i c a t e s comprised a pen  of s i x pigs (three male castrates and three females) which were group-fed. b.  Animals. A t o t a l o f 108 Yorkshire and Yorkshire x Landrace pigs were used  i n t h i s experiment.  Pigs were commenced on t r i a l a t an average body weight  of 16.9 k g , weighed weekly and sent f o r slaughter at a body weight o f 84 kg or over.  The two l a s t pigs i n the pen were withdrawn from t r i a l when the  body weight o f the heavier one exceeded 84 kg. on a random b a s i s .  Rations and pens were a l l o c a t e d  34 c.  Rations. The i n g r e d i e n t s f o r the s i x r a t i o n s are shown i n Table I .  The  t r i a l c o n s i s t e d o f s i x treatments as f o l l o w s : 1.  Barley-soybean meal t o supply 0.75% t o t a l l y s i n e (control ration)  2.  Barley + ,69% L - l y s i n e HC1 t o supply 0.90%  total  lysine 3.  Barley + .50% L - l y s i n e HC1 t o supply 0.75%  total  lysine 4.  Barley + .50% L - l y s i n e HC1 t o supply 0.75% l y s i n e + 0.05%  5.  total  L-threonine  Barley + .50% L - l y s i n e HC1 t o supply 0.75%  total  l y s i n e + 0.05% L-threonine + 0.10% DL-methionine 6.  Barley + .50% L - l y s i n e HC1 t o supply 0.75%  total  l y s i n e + 0.05% L-threonine + 0.10% DL-methionine + 0.10%  L-isoleucine.  The amino acidbcontent and chemical composition of the b a r l e y and the soybean meal are shown i n Table I I . The amino a c i d composition of each r a t i o n i s l i s t e d i n Table I I I .  A l l r a t i o n s were computed t o con-  t a i n adequate amounts of a l l n u t r i e n t s known t o be r e q u i r e d f o r growingf i n i s h i n g p i g s except t o t a l p r o t e i n and aniino a c i d content. d.  Management. (i)  Housing. The experiment was conducted a t the Swine Research U n i t ,  the U n i v e r s i t y of B r i t i s h Columbia.  The b u i l d i n g was  insulated,  w i t h a i r exhaust fans f i t t e d w i t h thermostatic c o n t r o l s set at 18.5°C.  The housing c o n s i s t e d of concrete f l o o r e d p a r t i a l l y  35 2 s l a t t e d pens w i t h an'area per p i g o f 1.2 m . ( i i ) Feeding and Watering. Pigs were f e d t h e i r r a t i o n s twice d a i l y a t 8:00 a.m. and 1:00 p.m.  Feeding was i n troughs on an ad l i b i t u m  b a s i s w i t h maximum allowance l i m i t e d t o 2.7 kg/day. D a i l y records o f feed consumption were kept.  Water was supplied  ad l i b i t u m by n i p p l e . (iii)  Feed Storage and Mixing. A l l feed ingredients were purchased and stored p r i o r  to the commencement o f the experiment t o ensure a uniform r a t i o n composition throughout. the whole form.  The b a r l e y was stored i n  As r e q u i r e d , 450 kg batches o f each r a t i o n  were prepared by hammer m i l l i n g the b a r l e y and then mixing i t w i t h the other ingredients i n a v e r t i c a l mixer* f o r 4 5 minutes.  On the f i r s t r e p l i c a t e the g r a i n was ground i n  a medium screen (10 mm diameter) but a f i n e screen (7 mm diameter) was used f o r r e p l i c a t e s two and three t o reduce s c a t t e r i n g o f feed which was a problem w i t h the coarser grind. e.  Records. A l l p i g s were weighed i n i t i a l l y and t h e r e a f t e r a t weekly i n t e r -  v a l s throughout the experiment.  Weekly feed consumption, corrected f o r  s p i l t f e e d , was a l s o recorded. f.  Chemical A n a l y s i s . A l l feed was analyzed f o r moisture, ash, crude p r o t e i n and ether  *  K e l l y Duplex M i l l Machinary, s i z e 220, s e r i a l 57364. Mfg. Co., S p r i n g f i e l d , Ohio.  The Duplex M i l l  36 e x t r a c t according t o A.O.A.C. methods (1960) and a c i d detergent f i b r e was determined according t o VanSoest method (1963).  Hydrolyzates o f the  b a r l e y and the soybean meal were analyzed f o r a l l e s s e n t i a l amino acids except tryptophan on a Phoenix* model 7800 amino a c i d analyzer equipped w i t h a VARIPUMP according t o the method described by Piez and Morris (1960). The hydrolyzates were prepared by a c i d h y d r o l y s i s (Kohler e t a l . 1967) except f o r c y s t i n e , methionine and tryptophan a n a l y s i s .  Cystine was deter-  mined as c y s t e i c a c i d and methionine as methionine sulfone by o x i d a t i v e h y d r o l y s i s (moore 1963).  The foregoing a n a l y s i s was done because o f the  losses o f methionine and c y s t i n e associated w i t h a c i d h y d r o l y s i s . For tryptophan a n a l y s i s , the b a r l e y were hydrolyzed w i t h the enzyme pronase and tryptophan was determined by spectrophotometical method (Spies e t a l . 1968). g.  Carcass Measurements. Dressed weight was measured on the hot carcass while the f o l l o w -  i n g measurements were made on the c h i l l e d carcass.  "A", "B" . and " c "  measurements were taken according t o the procedure o f Buck e t a l . (1962). The other carcass measurements were obtained according t o Canadian Record o f Performance f o r Swine (1967). Maximum shoulder f a t Minimum middle f a t Maximum l o i n f a t Eye muscle Area "A" measurement o f l o i n eye (width) "  Phoenix P r e c i s i o n Instrument Co., 3083-05 North 5 S t r e e t , P h i l a d e l p h i a , Pa. 19140, U.S.A.  37  "B" measurement o f l o i n eye (depth) "C" measurement o f f a t a t cut not i n c l u d i n g s k i n , i . e . , 40 mm from mid l i n e Carcass length h.  Calculations. Average d a i l y gain was determined as the b value i n the equation  derived from weekly body weights y = a + bx, where "y" i s body weight, "a"  i s i n i t i a l weight, and "x" days on t r i a l .  The average d a i l y feed con-  sumption and feed conversion r a t i o ( t o t a l feed eaten d i v i d e d by t o t a l body weight g a i n , both values expressed i n the same u n i t s ) were c a l c u l a t e d f o r each pen. i.  Carcass measurements were determined f o r each p i g .  S t a t i s t i c a l A n a l y s i s o f Data. The data were subjected t o an a n a l y s i s o f variance u s i n g , ^ l e a s t  squares technique as shown by Harvey (1960) which i s s u i t a b l e f o r comparing unequal sub-groups and hence relevant i n t h i s experiment w i t h missing values.  Means from comparisons showing a s i g n i f i c a n t " F value were t e s t e d 1  according t o the m u l t i p l e range t e s t o f Duncan (1955). was analyzed w i t h s t a r t i n g weight as the covariable.  D a i l y weight gain  Dressing percentage,  carcass l e n g t h , maximum shoulder f a t , mid b a c k f a t , maximum l o i n f a t , backfat 40 mm from m i d l i n e , l o i n area and l o i n area index were analyzed w i t h dressed weight as the c o v a r i a b l e .  38  Table I . Composition o f r a t i o n s used i n experiments I and I I ( A i r dry b a s i s )  Treatment  •t  2  3  4  5  6  %  %  %  %  %  Barley  83.10  96.05  96.24  96.19  .96.09  95.99  Soybean meal  13.76 0.69  0.50  0.50  0.50  0.50  0.05  0.05  0.05  0.102  0.102  1  Ingredients  L - l y s i n e HC1* L-threonine* DL-methionine* L-isoleucine*  0.10  Defluorinated rock phosphate  1.49  1.64  1.64  1.64  1.64  1.64 .  Limestone  0.57  0.54  0.54  0.54  0.54 .  0.54  Iodized s a l t  0.5  0.5  0.5  0.5  0.5  0.5  Copper s u l f a t e  0.078  0.078  0.078  0.078  0.078  0.078  Trace mineral and vitamin premix  0.5  0.5  0.5.  0.5  0.5  0.5  The trace mineral and vitamin premix provided the f o l l o w i n g per kg o f r a t i o n :  manganese 44 mg as MnSO^.H 0, Z i n c 110 mg as ZnSO .7H 0,  B.H.T. 500 mg, Vitamin A 3085 I.U., Vitamin Dg  440 I.U., Vitamin B  ±2  20 yg,  r i b o f l a v i n 2.9 mg, n i a c i n 11 mg, calcium pantothenate 11 mg (45% e q u i v a l e n t ) . * . The L - l y s i n e HC1 was f e d grade (Ajinomoto Co. , Japan) and wa's 98% pure, containing 78% L - l y s i n e . The L-threonine and L - i s o l e u c i n e were pure. The DL-methionine was 98% pure.  39  Table I I .  Content o f e s s e n t i a l amino acids and proximate constituents of b a r l e y and soybean meal on a dry matter b a s i s .  Concentration Component  Barley  Soybean Meal  Arginine (g/lOOg d.m.)  0.529  1.526  H i s t i d i n e (g/lOOg d.m.)  0.219  1.383  Isoleucine (g/lOOg d.m.)  0.345  2.135  Leucine (g/lOOg d.m.)  0.696  3.600  Lysine (g/lOOg d.m.)  0.434  3.578  Methionine (g/lOOg d.m.)  0.141  0.632  (Cystine) (g/lOOg d.m.)  0.178  0.614  Phenylalanine (g/lOOg d.m.)  0.617  3.025  (Tyrosine)  0.301  1.636  Threonine (g/lOOg d.m.)  0.293  2.010  Tryptophan (g/lOOg d.m.)  0.210  0.900  Valine (g/lOOg d.m.)  0.848  4.245  (g/lOOg d.m.)  Crude P r o t e i n '(.%) (N x 6.25)  10.50  53.78  Ash (%)  3.19  6.30  Crude f i b r e (%)  5.87  6.50  Crude f a t (%)  3.39  3.95  40  Table I I I . Content o f e s s e n t i a l amino acids o f each r a t i o n (g amino acid/lOOg mixed feed) on an a i r - d r y b a s i s . Ration Amino A c i d  1  2  3  4  5  Arginine  0. 56  0.,44  0. 44  0. 44  0. 44  0. 44  Histidine  0. 33  0..18  0. 18  0. 18  0. 18  0. 18  Isoleucine  0. 51  0..28  0. 28  0. 28  0. 28  0. 39  Leucine  0. 90  0.,57  0. 57  0. 57  0. 57  0. 57  Lysine  0. 75  0..90  0. 75  0. 75  0. 75  0. 75  Methionine  0. 18  0.,12  0. 12  0. 12  0. 17  0. 17  0. 20  0..15  0. 15  0. 15  0. 15  0. 15  0. 81  0.,51  0. 51  0. 51  0. 51  0. 51  0. 31  0..25  0. 25  0. 25  0. 25  0. 25  Threonine  0. 46  0..24  0. 24  0. 29  0. 29  0. 29  Tryptophan  0. 27  0..17  0. 17  0. 17  0. 17  0. 17  Valine  1.13  0..70  0. 70  0. 70  0. 70  0. 70  Dry- matter content %  89. 95  88..85  89. 12  88. 93  89. 16  89. 36  Crude p r o t e i n % (N x 6.25)  15. 81  10..15  10. 18  10. 12  10. 25  10. 31  (Cystine) Phyenylalanine (Tyrosine)  6  41  B.  RESULTS  The experimental data are summerized i n Table IV. There was a s i g n i f i c a n t d i f f e r e n c e between amino a c i d supplemented r a t i o n s and the c o n t r o l r a t i o n i n feed e f f i c i e n c y and d a i l y weight gain but not i n carcass quality.  Adding 0.05% L-threonine t o the lower l e v e l o f l y s i n e s i g n i f i c a n t l y *  improved d a i l y gain and feed conversion r a t i o compared t o the lower l e v e l of l y s i n e .  Further a d d i t i o n o f 0.10% DL-methionine e i t h e r alone o r i n com-  b i n a t i o n w i t h 0.10% L-isoleucine  d i d not improve performance but gave s i g -  n i f i c a n t l y higher d a i l y gain and a b e t t e r feed conversion r a t i o : than the lower l e v e l o f l y s i n e alone. Average d a i l y gain and feed e f f i c i e n c y f o r p i g s f e d the lower l e v e l o f l y s i n e were s i g n i f i c a n t l y lower than those f e d the higher l e v e l of l y s i n e .  The lower l e v e l o f l y s i n e gave s i g n i f i c a n t l y l e s s mid backfat  than the higher l e v e l o f l y s i n e but there was no s i g n i f i c a n t  difference  between the two l e v e l s o f l y s i n e i n other carcass measurements.  However,  the trend showed t h a t the lower l e v e l o f l y s i n e produced b e t t e r carcass q u a l i t y than the higher l e v e l . The a d d i t i o n o f 0.1% DL-methionine t o the l y s i n e and threonine supplemented r a t i o n reduced feed intake r e s u l t i n g i n a lower d a i l y gain but d i d not s i g n i f i c a n t l y a f f e c t feed conversion ratio;. The barley-soybean c o n t r o l r a t i o n gave a s i g n i f i c a n t l y higher weight g a i n , b e t t e r feed conversion r a t i o and measurements i n d i c a t i n g e r carcasses than the barley-amino a c i d r a t i o n s .  lean-  There was no s i g n f i c a n t  difference between treatments i n dressing percentage and maximum shoulder fat. *  The barley-soybean c o n t r o l r a t i o n produced l e s s backfat , and l a r g e r  Where s i g n i f i c a n c e i s i n d i c a t e d , i t r e f e r s t o s i g n i f i c a n c e a t the 5% level.  42 eye muscle areas and i n d i c e s . The lower l e v e l o f l y s i n e and supplementation gave a s i g n i f i c a n t l y greater d r e s s i n g percentage than the r a t i o n t o which both l y s i n e and threonine were added.  The minimum mid f a t measurement o f pigs r e c e i v i n g  the barley-soybean c o n t r o l r a t i o n was s i g n i f i c a n t l y l e s s than t h a t o f pigs r e c e i v i n g the higher l e v e l o f l y s i n e or the lower l e v e l of l y s i n e w i t h threonine and methionine.  The barley-soybean c o n t r o l r a t i o n produced l e s s  maximum l o i n f a t and l e s s backfat at 40 mm from the mid l i n e than the higher level of lysine.  The barley-soybean c o n t r o l r a t i o n produced a s i g n i f i c a n t l y  greater eye muscle area and eye muscle index than other treatments except f o r the lower l e v e l o f l y s i n e .  Adding threonine, methionine and  isoleucine  t o the lower l e v e l o f l y s i n e d i d not a f f e c t backfat or eye muscle measurements. Barrows gave s i g n i f i c a n t l y higher d a i l y weight gain than g i l t s while g i l t s had c o n s i s t e n t l y l e s s b a c k f a t , higher dressing percentage and l a r g e r eye muscle area.  Treatment and sex i n t e r a c t i o n was obtained f o r  d a i l y weight gain and f o r carcass q u a l i t y .  G i l t s f e d the higher l e v e l o f  l y s i n e gave a s i g n i f i c a n t l y higher d a i l y weight gain than those f e d the lower l e v e l of l y s i n e .  Supplementation w i t h l y s i n e , l y s i n e and threonine,  and l y s i n e , threonine, methionine and i s o l e u c i n e tended t o show higher d a i l y weight gain f o r barrows than g i l t s but supplementation w i t h l y s i n e , threonine and methionine produced an adverse e f f e c t .  43  Table IV. Summary o f the e f f e c t o f the a d d i t i o n o f amino acids t o b a r l e y on body weight g a i n , feed consumption (D.M.), feed conversion r a t i o n (D.M.) and carcass measurements i n feeding t r i a l .  Treatment  1 Soy Control  Starting Wt. (kg)  1 6  F i n a l Wt. (kg)  8 3  2 . 3 4 0.9% 0.75% l y s + lys l y s threo  1 6 > 6 3  83.20  ^gam f ??ily (kg) D.M. Feed(kg) Wt. gain (kg) Mean d a i l y feed intake (kg)  ±  ^  7  g  80.53  84.53  3.533  3.790  7  84.05  .498  3.320  .501  3.300  1 > 7 3 g  Results o f Significant Tests *  g 2  82.34  .461 .413 .525  2.954  6 l y s +threo +meth+isol  i y > 3 7  82.83  .609  1  5 lys+threo + meth  1 4 6 5 2  _  3.330  1 > 6 Q g  3  15 4 6 2 3 1 4 6 5 2. 3 ——  1 > g 5 3  Dressing %  78.36  78.67  79.46  78.05  78.44  78.52  3 2 6 5 14  Length cm  79.15  77.10 74.25  78.07  78.49  77.41  15 4 6 2 3  Max shoulder r a t (mm)  fat'Sm)  16  Max l o i n f a t (mm) ? h ?  f  a  w  3 7 > Q  3  2 1 > 1  2 5  2 g > y  ^  (40 mm) (mm)  Eye muscle index A x B (mm2) Eye Muscle area (mm?) — Experimental p e r i o d (days  Q  ^  -  4  3 3 > 5  -8  22.6  3714  3312  18  2 7 1 g  1 Q 1 > 1 +  2 4 y 6  1 4 6  3  J  ^  -  2 1  9  2  2 3  _  5  '  7  g > 7  2 3  '  X  3  2 4  Q  '  ^  5 2 6 4 3 1  3  2  20.5  21.2  3382  1 4 6  6  4  5  3  1  2 4 5 6 3 1  ±  2 5 3 2  _  3 ?  3415 2  _  8  20.5  3376  20.8  3286  ^  2 4 6 3 5  1  1 4 3 5 2 6 1 3 6 2 45  1 3 5 > 3  136.2  Treatment means not underscored by the same l i n e are s i g n i f i c a n t l y d i f f e r e n t at 5% l e v e l o f p r o b a b i l i t y (Duncan, 1955).  44 Table V. Comparison o f the e f f e c t s o f supplementation w i t h amino acids on d a i l y weight gains and carcass measurements o f g i l t s and barrows. Gilts  Barrows (  D a i l y Wt. Gain  Significant F  (s2)  V  517  Test 1  486  Carcass Measurement Dressing %  78. 01  79.,16  A A  Carcass length (cm)  77. 99  76.,83  N.S.  Max. shoulder f a t (mm)  39.,44  36.,19  Min. middle f a t (mm)  24. 69  21.,80  Max. l o i n f a t (mm)  32. 92  30.,85  22.,44  18..99  Backfat 40 mm from mid (mm) 2 Eye muscle index (mm ) 2 Eye muscle area (mm )  A A rfk  A  3243  3586  A A  2374  2658  A A  Treatment and sex i n t e r a c t i o n Treat. x Sex 1.  T  1 1  2.  T  2 1  3.  T  3 1  4.  T  4 1  5.  T  5 1  6.  D a i l y Wt. Gain (g)  S  S  S  S  S  Vl-  Treat. x Sex  D a i l y Wt. i  601  7.  T  476  8.  T S  467  9.  T  3 2  546  10.  T  4 2  483  11.  T  5 2  530  12.  T  6 2  618  1 2 S  2  446  2  359  S  505  S  513  S  473  S  Duncan's t e s t o f Treat, x Sex e f f e c t on weight gain a t 5% l e v e l o f probability. 7  1  4  6  11  10  5  2  12  3  8  9  * P < 0.05 ** P < 0.01 Treatment means not underscored by the same l i n e are s i g n i f i c a n t l y d i f f e r e n t .  45 C.  DISCUSSION  I t might be concluded from the r e s u l t s obtained i n t h i s feeding t r i a l , t h a t the g r o w i n g - f i n i s h i n g p i g could perform reasonably w e l l on a b a s a l r a t i o n o f Peace R i v e r b a r l e y supplemented w i t h l y s i n e and threonine, p r o v i d i n g a d d i t i o n a l vitamins and minerals were given.  However, the weight  gain and feed e f f i c i e n c y were somewhat l e s s w i t h the l y s i n e and threonine supplemented r a t i o n than w i t h the soybean supplemented c o n t r o l r a t i o n .  The  a d d i t i o n of methionine t o the r a t i o n alone o r i n combination w i t h i s o l e u c i n e d i d not improve performance beyond t h a t obtained w i t h the a d d i t i o n a l l y s i n e and threonine. Mean values i n d i c a t e d a s i g n f i c a h t l y b e t t e r performance w i t h t o t a l l y s i n e than w i t h 0.75%  t o t a l lysine.  0.90%  Obtained by the a d d i t i o n of  l y s i n e alone was i n f e r i o r t o t h a t obtained when other amino acids were a l s o added,  i n d i c a t i n g t h a t l y s i n e was not the only l i m i t i n g amino a c i d i n the  barley. L - l y s i n e supplementation  t o a high b a r l e y d i e t (75% b a r l e y meal,  23% wheat o f f a l ) f o r growing pigs has been shown elsewhere t o improve performance s i g n i f i c a n t l y (Braude e t a l . 1972). t o t a l l y s i n e compared w i t h 0.45%  This r a t i o n contained  0.57%  l y s i n e i n the unsupplemented h i g h b a r l e y  r a t i o n , thus approximating the l y s i n e content of a standard B r i t i s h b a r l e y meal-wheat o f f a l r a t i o n supplemented w i t h 7% white f i s h meal. (Evans 1960;  Jones et a l . 1962;  Many workers  E r i c s o n e t a l . 1962-; Ostrowski 1969) have  confirmed t h a t l y s i n e supplementation  t o p o o r - q u a l i t y p r o t e i n r a t i o n s im-  proved performance. Sure (1954) demonstrated t h a t wheat and rye were d e f i c i e n t i n l y s i n e and threonine and f u r t h e r t h a t rye was d e f i c i e n t i n v a l i n e f o r the growth of r a t .  Pond et a l . (1958) i n d i c a t e d t h a t l y s i n e and threonine were  46  probably the most l i m i t i n g amino acids i n milo f o r the growing r a t .  Rosen-  berg e t a l . (1959) e s t a b l i s h e d l y s i n e and threonine as the f i r s t and t h e second l i m i t i n g amino acids i n r i c e p r o t e i n f o r the growth o f the weanling rat.  Berry et_ a l . (1966) using a corn-soybean combination reported a  response t o supplementation w i t h l y s i n e and methionine t h a t was dependent on the a d d i t i o n o f threonine, i n d i c a t i n g t h a t t h i s amino a c i d was l i m i t i n g i n low-protein c o m soybean meal r a t i o n s f o r weanling p i g s .  MUller e t a l .  (1967a) showed t h a t l y s i n e and threonine supplementation t o a b a s a l c e r e a l d i e t had an e x t r a o r d i n a r i l y favourable e f f e c t upon gains and feed e f f i c i e n c y . The supplementation o f l y s i n e alone enhanced gain i n one case by 19% and i n another case by 22%.  The combination o f l y s i n e and threonine increased  gain by 59% i n the f i r s t t r i a l and by 92% i n the second, and the feed e f f i ciency was improved by 31 - 34% over t h a t obtained w i t h the unsupplemented control ration.  They considered from the viewpoint o f n u t r i t i o n that l y s i n e  was the f i r s t , threonine the second, tryptophan the t h i r d and methionine the f o u r t h l i m i t i n g amino a c i d ' i n the c e r e a l d i e t f o r the growing p i g s . The c e r e a l c o n s i s t e d o f wheat, b a r l e y and oats.  I n the present  experiment,the  mean d a i l y gain and feed e f f i c i e n c y values obtained w i t h the lower l e v e l of l y s i n e were markedly improved when 0.95% L-threonine was added t o the diet.  This i n d i c a t e d t h a t threonine was the second l i m i t i n g amino a c i d i n  the b a s a l r a t i o n o f b a r l e y which was i n agreement w i t h Sure (1954), Pond et a l . (1958), Rosenberg e t a l . (1959), Berry e t a l . (1966) and MUller e t a l . (1967a). The experiment  (Table I I I ) showed t h a t the b a s a l r a t i o n contained  :annsufficient l y s i n e , methionine, threonine and i s o l e u c i n e f o r growing pigs according t o the N.A.S.-N.R.C. standards (1968) but t h a t there was adequate tryptophan.  47 Although the methionine + c y s t i n e requirements o f growing pigs are widely accepted as being 0.5 - 0.6% o f the r a t i o n (A.R.C. 1967), there are some experiments which i n d i c a t e that 0.3 - 0.42% i s adequate f o r optimal growth (Beames and Pepper 1969, Oestemer e t a l . 1970).  I t could  be suggested t h a t the l a c k o f response t o methionine supplementation under some circumstances was due t o other f a c t o r s i n the r a t i o n being l i m i t i n g . However, the r e s u l t s o f Oestemer e t a l . (1970) would tend t o r e f u t e t h i s because they obtained good performance w i t h r a t i o n s i n which opaque-2 corn provided a l l the sulphur-containing amino a c i d s . 0.28% methionine + c y s t i n e .  The corn contained 0.23 -  N e i t h e r the r a t e o f g a i n , gain/feed nor pro-  t e i n e f f i c i e n c y r a t i o were s i g n i f i c a n t l y improved by supplementing the b a s a l corn r a t i o n s (Crude p r o t e i n 10.85%) w i t h 0.07, 0.14, 0.21 o r 0.28% DL-methionine.  Jensen e t a l . (1965) i n d i c a t e d t h a t the a d d i t i o n 0.20 o r  0.25% l y s i n e t o the approximately 8.0% crude p r o t e i n m i l o provided a balance o f e s s e n t i a l amino acids which supported gains equal t o t h a t o f f i n i s h i n g pigs f e d a corn-soybean 12.0% crude p r o t e i n d i e t . a response t o 0.10% DL-methionine  They were unable t o o b t a i n  i n a d d i t i o n t o the l y s i n e supplementation  even though the methionine plus c y s t i n e content o f the m i l o r a t i o n was only 0.25%. M u l l e r e t a l . (1967c) showed t h a t supplementing w i t h methionine and l y s i n e was not as e f f e c t i v e as. adding l y s i n e alone t o c e r e a l r a t i o n s containing 0.31% methionine p l u s c y s t i n e , and t h a t the enrichment o f c e r e a l d i e t s w i t h the combination o f l y s i n e plus threonine l e d t o an increase i n gain above the l e v e l a t t a i n e d by l y s i n e supplementation alone.  This agrees  w i t h the present study i n which l y s i n e and threonine supplementation o f b a r l e y improved performance whereas the f u r t h e r a d d i t i o n o f methionine had no e f f e c t . I t has been reported t h a t feeding c e r e a l mixtures  supplemented  48  w i t h l y s i n e , threonine, tryptophan, methionine and i n some experiments a l s o i s o l e u c i n e r e s u l t e d i n performance equal t o t h a t obtained w i t h d i e t s containing p r o t e i n concentrate (Robinson e t a l . 1963; MUller e t a l .  1967b).  MUller and Male*k (1967a, 1967b, 1967c) showed t h a t 'monodiets', i . e . , s i n g l e c e r e a l d i e t s (wheat, b a r l e y o r com) w i t h added amino acids could be used s u c c e s s f u l l y t o r e a r p i g s from weaning (average liveweight about 20 kg)^ Beames and Pepper (1969) i n d i c a t e d t h a t the use o f l y s i n e , e i t h e r w i t h o r without methionine, was not completely s u c c e s s f u l as a replacement o f h a l f the soybean meal i n a g r a i n plus 15 percent soybean r a t i o n f o r pigs of l e s s than 45 kg body weight.  From a body weight o f 45 kg t o the slaughter  weight o f approximately 90 k g , the above authors showed that h a l f o f 15% soybean meal could be replaced by amino acids without reducing the growth o f the p i g s , although r e s u l t s w i t h t h i s type o f supplement i n combination w i t h sorghum over the body weight range (20 - 89 kg) were not as s a t i s f a c t o r y as f o r wheat.  I n the present experiment, the replacement o f p r o t e i n con-  centrates such as soybean meal by l y s i n e , l y s i n e plus threonine, l y s i n e plus threonine plus methionine plus i s o l e u c i n e d i d not improve the performance t o equal t h a t o f the barley-soybean c o n t r o l r a t i o n , but supplementation w i t h these amino acids s i g n i f i c a n t l y improved performance above t h a t obtained by adding l y s i n e alone.  Performance o f animals on amino a c i d  b a r l e y r a t i o n s was i n f e r i o r t o the barley-soybean c o n t r o l r a t i o n .  supplemented This i s  i n agreement w i t h Beames e t a l . (1968), Beames and Pepper (1969), and Barber e t a l . (1969), but i n disagreement w i t h Robinson e t a l . (1963) and MUller e t a l . (1967b).  I t i s p o s s i b l e that the response t o the a d d i t i o n of l y s i n e  and threonine t o the b a r l e y r a t i o n was l i m i t e d by e i t h e r the l e v e l o f t o t a l N i n the r a t i o n , which was markedly lower than the l e v e l i n the barley-soybean c o n t r o l r a t i o n , o r a lower b i o l o g i c a l a v a i l a b i l i t y o f l y s i n e and threonine  49 or other e s s e n t i a l amino a c i d s . Bayley e t a l . (1968) i n d i c a t e d t h a t the supplementation p r a c t i c a l corn-soybean r a t i o n w i t h e i t h e r 0.1% l y s i n e o r 0.05%  of a  methionine  had no b e n e f i c i a l e f f e c t on growth r a t e or feed e f f i c i e n c y , but w i t h the l e v e l s used there was a p o s i t i v e e f f e c t on gain when both amino acids were added together.  The e f f e c t was marked f o r the low-protein r a t i o n , but  making up the d i f f e r e n c e i n lysine, and s u l f u r amino acids d i d not overcome the d i f f e r e n c e i n gains between the two d i e t a r y p r o t e i n l e v e l s . E r i c s o n e t a l . (1962) showed t h a t supplementation  with L-lysine  HC1 markedly increased d a i l y gain (40 - 60%) and decreased the amount o f feed per kg of gain (25 - 30%), when the b a s a l r a t i o n consisted of 27% and 63% b a r l e y p r o t e i n a n d , t h a t there was some response due t o the L - l y s i n e 9  HC1 supplementation  i n s p i t e o f the r e l a t i v e l y high l e v e l o f added f i s h  meal and soybean meal.  This experiment a l s o i n d i c a t e d t h a t  supplementation  w i t h p r o t e i n concentrates gave f a r b e t t e r gain and feed e f f i c i e n c y than supplementation  w i t h amino acids.  B l a i r e t a l . (1969) showed t h a t l i v e w e i g h t gain was not improved s i g n i f i c a n t l y by i n c r e a s i n g the p r o t e i n l e v e l above 16, 14 and 12% respect i v e l y , f o r the 2 3 - 4 5 ,  45 - 68  and  68 - 90 kg body weight categories.  However, feed conversion e f f i c i e n c y was improved s i g n i f i c a n t l y during the 23 - 45 kg range by i n c r e a s i n g the p r o t e i n l e v e l t o 18%.  Lean meat produc-  t i o n and the e f f i c i e n c y of conversion of feed t o lean meat were improved by i n c r e a s i n g the above p r o t e i n l e v e l s s l i g h t l y .  Liveweight gain was  improved s i g n i f i c a n t l y by i n c r e a s i n g the l y s i n e l e v e l above 1.04, 0.70%, r e s p e c t i v e l y , f o r the 2 3 - 4 5 ,  45 - 68  0.74  not and  and 68 - 90 kg ranges.  However, feed conversion e f f i c i e n c y was improved s i g n i f i c a n t l y during the 23 - 45 kg stage by i n c r e a s i n g the l y s i n e l e v e l t o 1.22%.  R a i s i n g the  50  l y s i n e l e v e l a t each l e v e l o f p r o t e i n had no s i g n f i c a n t e f f e c t on the rate and e f f i c i e n c y o f lean meat gain. Generally animals require more amino a c i d s , e s p e c i a l l y l y s i n e i n e a r l y growth and gradually decrease t h e i r requirement w i t h age.  I n the  present experiment,higher l e v e l s o f l y s i n e (0.90%) gave a s i g n i f i c a n t l y higher mean d a i l y weight gain and b e t t e r feed e f f i c i e n c y than the lower l e v e l o f l y s i n e (0.75%).  P i g performance showed that there was not much  d i f f e r e n c e between the two l e v e l s o f l y s i n e i n the e a r l y stages but the higher l e v e l o f l y s i n e gave improved mean d a i l y weight gain and feed e f f i ciency than the lower l e v e l i n the l a t e r stages (Figure 2, Figure 3). I t i s p o s s i b l e that the response t o the higher l e v e l o f l y s i n e was l i m i t e d during e a r l y growth by the l e v e l o f crude p r o t e i n i n the r a t i o n .  In this  experiment, threonine was the second l i m i t i n g amino a c i d f o r pigs since supplements o f l y s i n e and threonine t o the b a r l e y produced next t o that o f pigs f e d the barley-soybean c o n t r o l r a t i o n .  performance Braude e t a l .  (1972) and Morrison e t a l . (1961) suggested t h a t l l y s i n e supplementation r e s u l t s i n a progressive decrease i n plasma threonine concentration.  The  higher l e v e l o f l y s i n e was perhaps more imbalanced i n the e a r l y stage than i n l a t e r stages.  A l e v e l o f 0.29% threonine i n these r a t i o n s was consider-  ably lower than the published threonine requirement (0.45%) according t o N.A.S.-N.R.C. (1968) but i s adequate i n the l a t e r stages since the r e q u i r e ment o f threonine i s 0.27% (crude p r o t e i n 12%) by c a l c u l a t i o n s which are based upon the assumption t h a t the requirements f o r a l l amino acids expressed as a percentage o f the p r o t e i n , decrease l i n e a r l y as the d i e t a r y p r o t e i n increases (Becker e t a l . 1963).  Therefore, i n the l a t e r stage, pigs can  u t i l i z e more l y s i n e than i n the e a r l y stage.  Pierce and Bowland (1972)  showed t h a t the a d d i t i o n o f 0.2% L - l y s i n e HC1 alone; t o the low p r o t e i n d i e t  51  ( C P . 14%, l y s i n e 0.57%) improved feed i n t a k e i n the growing and f i n i s h i n g p e r i o d and the o v e r a l l p e r i o d but not i n the s t a r t i n g p e r i o d compared w i t h the low p r o t e i n unsupplemented d i e t .  B l a i r e t a l . (1969) showed t h a t feed  e f f i c i e n c y improved s i g n i f i c a n t l y during the 23 - 45 kg stage by i n c r e a s i n g the l y s i n e l e v e l t o 1.22%.  I n the present experiment pigs fed the higher  l e v e l o f l y s i n e gave b e t t e r feed intake and growth r a t e than those r e c e i v i n g the lower l e v e l o f l y s i n e i n the l a t e r stage but not i n the e a r l y stage (Figure 2 ) , but the higher l e v e l gave s l i g h t l y b e t t e r feed e f f i c i e n c y than the lower l e v e l o f l y s i n e i n the e a r l y stage.  These r e s u l t s were i n agree-  ment w i t h B l a i r e t a l . (1969), and P i e r c e and Bowland (1972). In p a r t i c u l a r , a t t e n t i o n may be drawn t o the carcass q u a l i t y i n t h i s experiment.  I t i s q u i t e understandable t h a t an energy excess w i l l  l e a d t o f a t t e r carcasses.  In the present experiment d a i l y feed intake was  1.55 - 1.78 kg over a l l p e r i o d .  This f i g u r e showed t h a t the t o t a l energy  intake would not be i n excess s i n c e b a r l e y was used as a b a s a l r a t i o n . I t i s worthwhile i n t h i s respect to determine not only nrinimum but i n p a r t i c u l a r optimum requirements, i f q u a l i t y meat i s t o be obtained economically from heavy p i g s .  Backfat measurements o f pigs given the lower  l e v e l o f l y s i n e were o f lower magnitude than those o f pigs r e c e i v i n g the higher l e v e l o f l y s i n e .  Mid backfat was s i g n i f i c a n t l y l e s s but maximum  shoulder f a t , maximum l o i n f a t and backfat at 40 mm from the mid l i n e were not s i g n i f i c a n t l y l e s s .  Dressing percentage, eye muscle area and eye muscle  index were not s i g n i f i c a n t l y a f f e c t e d by l e v e l s of l y s i n e  supplementation  but the treiid showed t h a t the lower l e v e l of l y s i n e gave a higher dressing percentage, a l a r g e r eye muscle area and a l a r g e r eye muscle index.  This  trend might come from e i t h e r amino a c i d imbalance a t given p r o t e i n l e v e l s o r other l i m i t i n g f a c t o r s .  The higher l e v e l o f l y s i n e (0.90%) at approxi-  52  mately 11% p r o t e i n would be i n excess of the growing p i g s requirements compared t o 0.58% l y s i n e at 11.6% p r o t e i n (Brinegar 1949), 0.71%  lysine  at 12.8% p r o t e i n d i e t (McWard 1959) and 0.70% l y s i n e when the r a t i o n cont a i n e d 10 o r 15% p r o t e i n (Chance e t a l . 1958).  This excess of l y s i n e might  cause an amino a c i d imbalance since performance showed t h a t threonine was limited. Low-protein r a t i o n s based on b a r l e y and/or wheat or corn p r o p e r l y balanced by supplementation w i t h l y s i n e produced leaner carcasses than unsupplemented low-protein r a t i o n , as shown by Brooks e t a l . (1959), Bowland (1962), C a h i l l y e t a l . (1963), N i e l s e n et a l . (1963), Braude e t a l . (19720. Adding threonine t o the lower l e v e l o f l y s i n e had no s i g n i f i c a n t e f f e c t on b a c k f a t , eye muscle area and d r e s s i n g percentage.  This would  have been'partly explained by a d i f f e r e n c e i n feed intake as the feed intake on the lower l e v e l o f l y s i n e was 1.55 kg per day w h i l e f u r t h e r a d d i t i o n of threonine increased t h i s t o 1.74 kg per day f o r the whole period.  The  f u r t h e r a d d i t i o n of methionine, alone or i n combination w i t h i s o l e u c i n e , d i d not a f f e c t b a c k f a t , eye muscle area, eye muscle index o r d r e s s i n g percentage.  This i n d i c a t e d t h a t there was no response from adding methionine  and i s o l u e c i n e on carcass q u a l i t y as w e l l as performance o f p i g s . Clausen (1959-1964) c o l l e c t e d a large q u a n t i t y o f data showing t h a t amino a c i d supplementation o f p r o t e i n concentrates f e d as  supplements  t o b a r l e y d i e t s have a l s o e f f e c t e d a marked improvement i n the carcass leanness o f the Danish pigs. In the present experiment, the barley-soybean c o n t r o l r a t i o n (about 17% C P . )  gave the lowest backfat t h i c k n e s s , l a r g e r eye muscle area and  higher eye muscle index.  Work by Bowland e t a l . (1959), Ashton et a l .  (1955),  Becker e t a l . (1956) and r e s u l t s summarized by A.R.C. (1967), a l l support the  53  view t h a t lowering the crude p r o t e i n l e v e l below about 16-17%, a t l e a s t i n the i n i t i a l stages o f the growing p e r i o d , w i l l produce adverse e f f e c t s on carcass q u a l i t y .  These r e s u l t s are i n agreement w i t h the observations  f o r t h i s study that pigs f e d a barley-soybean c o n t r o l r a t i o n produced b e t t e r carcass q u a l i t y than pigs f e d lower p r o t e i n (about 11%) amino a c i d supplemented b a r l e y but Clawson (1967), Meade e t a l . (1966) and Pierce and Bowland (1972) reported no i n f l u e n c e o f d i e t a r y p r o t e i n on l o i n area and backf a t thickness.  Pierce and Bowland (1972) suggested t h a t l a c k o f treatment  e f f e c t s on t o t a l backfat thickness and on l o i n area was due t o a wide tolerance l e v e l f o r d i e t a r y p r o t e i n l e v e l s before gross carcass changes were noted ( p r o t e i n l e v e l was 14, 17 and 20%). Barrows gave s i g n i f i c a n t l y higher d a i l y weight gain than g i l t s which i s i n agreement w i t h Tjong-A-Hung e t a l . (1972) but which i s i n disagreement w i t h Newell and Bowland (1972) and Pierce and Bowland (1972). G i l t s were s u p e r i o r t o barrows i n a l l carcass measurements except carcass length.  These r e s u l t s are i n agreement w i t h Wong e t a l . (1968), Newell  and Bowland (1972) .and Pierce and Bowland (1972), and Tjong-A-Hung e t a l . (1972) who showed t h a t g i l t s had lower backfat measurements and l a r g e r eye muscle area. There was not much d i f f e r e n c e i n weight gain between the two l e v e l s o f l y s i n e f o r barrows, but g i l t s had a s i g n i f i c a n t l y d i f f e r e n t r e s ponse t o lysine, l e v e l s .  This was i n agreement w i t h Robinson (1964) who  showed that the response o f g i l t s continued w i t h i n c r e a s i n g p r o t e i n and l y s i n e l e v e l s i n the d i e t s while that o f barrows ceased a t a much lower level.  Adding l y s i n e and threonine r e s u l t e d i n a s i m i l a r improvement i n  the growth rate o f both barrows and g i l t s when compared w i t h the a d d i t i o n of l y s i n e alone.  Further adding methionine w i t h o r without i s o l e u c i n e d i d  54 not give consistant r e s u l t s .  These r e s u l t s may be caused by a d i f f e r e n t  amino a c i d requirement o f sex. Therefore, f u r t h e r study on sex and supplementation w i t h amino acids i n t e r a c t i o n would give more r e l i a b l e r e s u l t s when a separated feeding system according t o sex i s adopted.  4  5  6  10  n  12  13  14  15  Weeks on t r i a l cn cn  Figure 1. The effect of supplementation with lysine and threonine of basal ration of barley (Treat. 4) compared to the control ration (Treat. 1) on mean body weight from the start until f i r s t pigs sent for slaughter.  Treat. 3 Treat. 2 Treat. 4 Treat. 1  a  . 3  6  7  8  10  11  12  13  14  15  Weeks on t r i a l Figure 111.  The effect of supplementation with lower level of lysine (Treat. 3 ) , higher level of lysine (Treat. 2 ) , lysine and threonine (Treat. 4) and control ration (Treat. 1) on Feed efficiency ratio from start until f i r s t pigs sent for slaughter.  58  D. CONCLUSION Pigs fed the lower l e v e l o f l y s i n e had a s i g n i f i c a n t l y lower growth r a t e and poorer feed e f f i c i e n c y than those f e d the higher l e v e l o f lysine.  The trend t h a t pigs f e d the lower l e v e l o f l y s i n e were leaner and  w i t h l a r g e r eye muscle areas than those fed the higher l e v e l o f l y s i n e . These r e s u l t s could be explained on the b a s i s o f a slower growth r a t e , everything e l s e being equal, producing a leaner carcass. Adding 0.05% L-threonine t o the lower l e v e l o f l y s i n e improved feed i n t a k e , d a i l y weight gain and feed e f f i c i e n c y but not carcass q u a l i t y above the improvement r e s u l t i n g from the a d d i t i o n o f l y s i n e alone t o the b a s a l r a t i o n of b a r l e y .  The f u r t h e r a d d i t i o n o f 0.10% DL-methionine w i t h  o r without 0.10% L - i s o l e u c i n e d i d not improve feed i n t a k e , d a i l y weight g a i n , feed e f f i c i e n c y o r carcass q u a l i t y .  Nor d i d supplementation  with  these amino acids t o the lower l e v e l o f l y s i n e improve carcass q u a l i t y . I n t h i s experiment threonine was the second l i m i t i n g amino a c i d i n Peace R i v e r b a r l e y a f t e r l y s i n e , which i s w e l l known as the f i r s t l i m i t i n g amino a c i d i n b a r l e y f o r growing p i g s .  By adding 0.05% L-threonine t o the lower l e v e l  o f l y s i n e mean d a i l y gain improved by 27.1% and feed e f f i c i e n c y by 14%. However, supplementation  w i t h l y s i n e and threonine r e s u l t e d i n a considerably  i n f e r i o r performance than t h a t obtained w i t h barley-soybean  control ration,  w i t h d a i l y weight g a i n , feed e f f i c i e n c y and carcass q u a l i t y being s i g n i f i c a n t l y poorer.  I t was p o s s i b l e t h a t the b a r l e y d i e t even w i t h the a d d i t i o n  o f the four amino a c i d s , was l i m t i n g e i t h e r i n the l e v e l o f t o t a l N o r as a r e s u l t o f an imbalance o f amino acids was due t o a low threonine l e v e l since a d d i t i o n o f 0.05% L-threonine was d e f i c i e n t i n the r a t i o n f o r growi n g pigs by N.A.S.-N.R.C. (1968).  E i t h e r adding n i t r o g e n o r adding more  threonine, o r both may improve performance compared t o t h a t o f the present experiment.  59  IV. A. a.  EXPERIMENT I I  EXPERIMENTAL PROCEDURE  General. Although growth performance i s an important parameter i n p r a c t i c a l  animal production, weight gain and feed conversion r a t i o give only an i n accurate measure o f nitrogen u t i l i z a t i o n .  Nitrogen balance values are o f  much greater value i n assessing p r o t e i n q u a l i t y .  The f o l l o w i n g experiment  was done t o obtain n i t r o g e n absorption and u t i l i z a t i o n data t o compliment the r e s u l t s obtained i n the main feeding experiment (experiment I ) using the same r a t i o n s . The experiment u t i l i z e d three groups each of s i x p i g s , w i t h each group maintained i n d i g e s t i b i l i t y crates f o r a three-week period.  Within  groups the s i x experimental r a t i o n s were randomly a l l o c a t e d , w i t h each p i g r e c e i v i n g the same r a t i o n f o r the three-week p e r i o d (Table VI). week was an a c c l i m a t i z a t i o n period.  The f i r s t  The second and t h i r d weeks were d i v i d e d  i n t o the two one-week c o l l e c t i o n periods. b.  Animals. A t o t a l o f 18 male c a s t r a t e Yorkshire pigs between 30 kg and 45  kg i n three groups o f s i x were used. c.  Rations. Rations were the same as those used i n experiment I .  d.  Management. (i)  Housing The metabolism room was i n s u l a t e d and supplied  w i t h space heaters which kept the temperature a t approximately 21 ± 1° C.  The metabolism crates were  60  a m o d i f i c a t i o n o f the S h i n f i e l d design (Frape e t a l . 1968).  The u r i n e t r a y which was i n c l i n e d from f r o n t  t o reat a t an angle o f approximately 30° from the h o r i z o n t a l was made o f f i b r e g l a s s . was made o f p l a s t i c .  The feces t r a y  I n order t o prevent some pigs  from t u r n i n g i n the crates i n the a c c l i m a t i z a t i o n p e r i o d a sheet o f plywood board was attached t o both side o f the c r a t e s .  A f i n e wire screen was placed  on the urine t r a y i n order t o r e t a i n the small amount of feces which f e l l a n t e r i o r t o the r e a r o f the f l o o r (Figure IV and V). (ii)  Feeding and watering Pigs were f e d twice d a i l y ad l i b i t u m a t 9:00 a.m.  and 2:00 p.m. f o r 40 minutes on r a t i o n which was mixed w i t h water (feed:water = 1:1) j u s t before feeding. Water was given a f t e r the afternoon feeding ad l i b i t u m f o r 20 minutes.  Feed residues were removed, put i n t o  p l a s t i c bags and stored a t 3° C.  At the end o f each  one-week c o l l e c t i o n p e r i o d , the residues f o r each p i g were pooled and d r i e d a t 60° C f o r 72 hours. (iii)  Mixing r a t i o n s Each r a t i o n was prepared by passing the b a r l e y  through the f i n e screen (7 mm diameter) o f a hammer m i l l . Feed samples were taken f o r determination o f moisture and nitrogen a t the time o f feeding the r a t i o n , e.  Feces and Urine C o l l e c t i o n A l l feces from each p i g were c o l l e c t e d i n p l a s t i c bags and stored  61  at 3 C u n t i l completion o f the seven-day t r i a l .  The t o t a l f e c a l output  of each p i g was then pooled and weighed, and a 400 g a l i q u o t d r i e d a t 60°C f o r 72 hours (Saben and Bowland 1971).  The d r i e d feces were ground  and stored f o r l a t e r measure o f nitrogen and moisture.  Urine was c o l l e c t -  ed i n a p l a s t i c j a r t o which was added 50 ml d i l u t e d s u l p h u r i c a c i d (50% V/V) each day.  Each day urine volume was measured and a 10% a l i q u o t e r e -  t a i n e d a t 3°C f o r p o o l i n g a t the end o f the experiment. was used f o r subsequent n i t r o g e n f.  The pooled urine  determination,  S t a t i s t i c a l A n a l y s i s o f Data. The data f o r n i t r o g e n balance, apparent n i t r o g e n d i g e s t i b i l i t y ,  n i t r o g e n r e t a i n e d as a percentage o f nitrogen absorbed, nitrogen r e t a i n e d as a percentage o f n i t r o g e n intake and dry matter d i g e s t i b i l i t y were subj e c t e d t o an a n a l y s i s o f variance (UBC-LSA8) and means from comparison showing s i g n i f i c a n t F values were t e s t e d according t o the m u l t i p l e range t e s t o f Duncan (1955).  Nitrogen balance data were analyzed by covariance  (UBC-LSA8) w i t h feed intake because o f .highly s i g n i f i c a n t covariance.  62  Table VI. A l l o c a t i o n o f p i g s w i t h i n r e p l i c a t e s and periods f o r Experiment I I  Rations  Period  1 2 3 4 Soy Control 0.9% l y s 0.75% l y s lys+threo  (Weeks)  5 lys+threo +meth  6 lys+threo +meth+isoleu  , P i g No. T  1  1  2  3  4  5  6  2  1  2  3  4  .5  6  3  1  2  3  4  5  6  4  7  8  9  10  11  12  5  7  8  9  10  11  12  6  7  8  9  10  11  12  7  13  14  15  16  17  18  8  13  14  15  16  17  18  9  13  14  15  16  17  18  Figure V.  P i g shown i n the cage which could be adjusted f o r the s i z e o f p i g .  64  B.  RESULTS  The r e s u l t s o f the metabolism t r i a l are shown i n Table V I I . The a d d i t i o n o f 0.50% L - l y s i n e HC1 (0.75% t o t a l l y s i n e ) t o the b a s a l r a t i o n o f b a r l e y produced a s i g n i f i c a n t l y b e t t e r n i t r o g e n balance than the a d d i t i o n o f 0.69% L - l y s i n e HC1 (0.90% t o t a l l y s i n e ) .  However, when n i t r o g e n balance  was adjusted f o r feed i n t a k e , there was no s i g n i f i c a n t d i f f e r e n c e between two l e v e l s o f L - l y s i n e .  The a d d i t i o n o f 0.05% L-threonine t o the lower  l e v e l o f l y s i n e d i d not s i g n i f i c a n t l y improve n i t r o g e n balance and a l s o d i d not when n i t r o g e n balance was adjusted -for feed intake.  No f u r t h e r improve-  ment o f n i t r o g e n balance was achieved by the a d d i t i o n o f 0.10% DL-methionine t o the lower l e v e l o f l y s i n e .  However, when n i t r o g e n r e t e n t i o n was adjust-  ed f o r feed i n t a k e , adding 0.10% DL-methionine w i t h o r without 0.10% Li s o l e u c i n e f u r t h e r improved the q u a l i t y o f b a r l e y p r o t e i n above that observed w i t h l y s i n e alone.  Adding 0.10% L - i s o l e u c i n e t o the above r a t i o n improved  nitrogen balance when n i t r o g e n balance was adjusted by feed intake. Nitrogen absorbed as a percentage o f N intake tended t o be improved more by the a d d i t i o n o f 0.05% L-threonine t o the lower l e v e l o f l y s i n e but t h i s increase was not s i g n i f i c a n t .  Further improvement o f N absorbed/N  intake was obtained from the a d d i t i o n o f methionine e i t h e r alone o r i n combination with isoleucine.  When n i t r o g e n absorbed was expressed as a percentage  o f n i t r o g e n consumed, the barley-soybean c o n t r o l r a t i o n was s i g n i f i c a n t l y higher than the barley-amino acids r a t i o n s . Nitrogen r e t a i n e d as a percentage o f N absorbed was improved more by the 'addition. ..of 0.05% L-threonine t o the lower l e v e l o f l y s i n e than by adding the l y s i n e alone t o the b a r l e y r a t i o n .  The lower l e v e l o f l y s i n e  gave a b e t t e r value f o r N r e t a i n e d as a percentage o f N absorbed than the higher l e v e l o f l y s i n e .  The barley-soybean c o n t r o l r a t i o n gave the second  65  lowest N r e t a i n e d as a percentage o f N absorbed.  The lowest value was  obtained w i t h the b a r l e y plus the higher l e v e l o f l y s i n e .  Further a d d i t i o n  o f methionine and i s o l e u c i n e gave s i g n i f i c a n t l y higher b i o l o g i c a l value than the barley-soybean c o n t r o l r a t i o n and adding l y s i n e alone t o the barley. Nitrogen r e t a i n e d , when expressed as a percentage o f n i t r o g e n consumed was not s i g n i f i c a n t l y d i f f e r e n t f o r the grain-soybean c o n t r o l r a t i o n and the r a t i o n s containing threonine, w i t h o r without methionine and i s o l e u c i n e , but a l l except the grain-threonine r a t i o n gave a higher r e t e n t i o n than the g r a i n - l y s i n e combination. The r e s u l t s showed t h a t the major e f f e c t o f improving p r o t e i n q u a l i t y was due t o the threonine a d d i t i o n t o the lower l e v e l o f l y s i n e . The a d d i t i o n o f methionine and i s o l e u c i n e gave n o n - s i g n i f i c a n t improvement i n N balance which was adjusted f o r feed i n t a k e , N d i g e s t i b i l i t y , b i o l o g i c a l value and N r e t a i n e d as a percentage o f N consumed, but a s l i g h t response.  66  Table V I I .  Summary o f the e f f e c t s o f supplementation o f b a r l e y w i t h amino acids on apparent dry matter d i g e s t i b i l i t y , n i t r o g e n balance, apparent n i t r o g e n d i g e s t i b i l i t y and on n i t r o g e n r e t a i n e d as a percentage o f n i t r o g e n absorbed (average 7-day f i g u r e s ) .  Treatment  1 2 Soy 0.9% Control l y s  T o t a l feed intake (g)  9801  8660  Total N intake (g)  267.03 150.70  N balance (g)  120.37  3 4 0.75% l y s + l y s threo  10437  5 lys+threo + + meth  99841  8404  179.221168888 144.33  55.16  68.56  70.84  63.61  6 lys+threo +meth+isol  10199 171.17 1 4 6 3 52 70.50  N balance a  SrS^e  1 1 7 , 3 7  6 0 , 4 5  6 1 , 6 7  5 8 , 0 3  l 7 0 , 6 7  Results o f Significant Tests *  69.52  1 5 6 4 32  .(g) N absorbed N intake "°  76.05  64.58  61.95 64.43  66.01  66.18  N retained N intake "°  45.10  36.61  38.26  44.Oi  43.50  0  0  N absorbed  %  D.M. digestibility  5 9 , 3 9  5 6 , 6 2  78.70  77.32  6 1 , 7 6  42.24  6 5 , 4 3  76.45  6 6 , 8 0  77.11  78.18  64.60  78.22  1 6 5 2 4 3 1 5 6 4 32  5 4 6 3 12  1 6 5 2 4 3  Treatment means not underscored by the same l i n e are s i g n i f i c a n t l y at 5% l e v e l o f p r o b a b i l i t y (Duncan, 1955).  different  67  C.  DISCUSSION  Although there were s l i g h t v a r i a t i o n s i n the r e l a t i v e e f f e c t s o f treatments, the values f o r N balance, N absorbed/N i n t a k e , N retained/N absorbed and N retained/N intake were i n reasonably close agreement i n showing a progressive improvement i n nitrogen r e t e n t i o n by the a d d i t i o n of L-threonine, DL-methionine and i s o l e u c i n e t o the b a r l e y plus l y s i n e . The r e s u l t s i n d i c a t e d that the threonine content o f b a r l e y was d e f i c i e n t f o r growing pigs since the main improvement i n p r o t e i n q u a l i t y was associated w i t h the a d d i t i o n o f threonine and l y s i n e i n contrast t o the a d d i t i o n o f l y s i n e alone.  Further a d d i t i o n o f methionine w i t h o r without i s o l e u c i n e  d i d not s i g n i f i c a n t l y improve N balance, N d i g e s t i b i l i t y , b i o l o g i c a l value and N retained/N absorbed above t h a t obtained l y s i n e and threonine  only.  An improvement i n nitrogen balance by the a d d i t i o n o f L - l y s i n e HC1 t o g r a i n has been reported by many authors (Ericson e t a l . 1962; Bowland and Grimson 1969;  Pick e t a l .  1971).  Braude e t a l . (1972) i n d i c a t e d  that N r e t e n t i o n as a percentage o f N intake tended t o be higher w i t h l y s i n e supplementation t o b a r l e y than w i t h unsupplemented b a r l e y f o r growingf i n i s h i n g pigs.  Solberg (1971) showed t h a t compared w i t h a moderately  l y s i n e - d e f i c i e n t d i e t , l y s i n e a d d i t i o n s had no s i g n i f i c a n t e f f e c t on e i t h e r the d i g e s t i b i l i t y o r the metabolizable energy content o f the d i e t but' a l y s i n e d e f i c i e n c y caused a decreased nitrogen r e t e n t i o n , an increased u r i c a c i d biosynthesis and an increased feed intake i n chicks. P i c k e t a l . (1971) showed t h a t r a t s f e d d i e t s containing 0.73% l y s i n e had s i g n i f i c a n t l y (p <_ 0.01)  greater gain/feed r a t i o and r e t a i n e d  more nitrogen than those fed 0.54% l y s i n e d i e t s .  However, i n c r e a s i n g the  d i e t a r y l y s i n e t o 0.92% d i d not e f f e c t f u r t h e r improvements i n any o f the response c r i t e r i a .  A l s o these r e s u l t s i n d i c a t e d that the l e v e l o f d i e t a r y  68  i s o l e u c i n e d i d not exert a s i g n i f i c a n t e f f e c t on d a i l y g a i n , gain/feed, N balance and N r e t a i n e d as a percentage of N absorbed.  In the  present  experiment,the lower l e v e l o f l y s i n e gave b e t t e r N balance and N retained/N absorbed than the higher l e v e l of l y s i n e , and the lower l e v e l of l y s i n e had a s l i g h t l y b e t t e r N retained/N intake value.  Therefore, the lower  l e v e l of l y s i n e (0.75% t o t a l l y s i n e ) was more s u i t a b l e than the higher l e v e l of l y s i n e (0.90% t o t a l l y s i n e ) i n the b a r l e y r a t i o n f o r growing pigs which was supported by P i c k e t a l . (1971) who  showed t h a t 0.73%  l y s i n e was  adequate i n an opaque-2 corn r a t i o n f o r growing r a t s . The lower l e v e l , o f l y s i n e gave a s i g n i f i c a n t l y higher b i o l o g i c a l value and s l i g h t l y b e t t e r net p r o t e i n u t i l i z a t i o n than the higher l e v e l o f l y s i n e although d i g e s t i b i l i t y of n i t r o g e n d i d not d i f f e r .  Therefore,  the d i f f e r e n t r e s u l t s of the two l e v e l s of l y s i n e seemed t o be derived from N r e t e n t i o n but not N absorption.  I t i s p o s s i b l e t h a t the response  t o the higher l e v e l of l y s i n e was due t o e i t h e r an excessive amount of l y s i n e which would give r i s e t o an imbalance of amino acids because the threonine was d e f i c i e n t i n the r a t i o n according t o N.A.S.-N.R.C. standard (1968) o r t o a lower amount of n i t r o g e n intake than t h a t of the lower l e v e l o f l y s i n e since nitrogen r e t e n t i o n increases as n i t r o g e n intake increases. Bressani (1971) i n d i c a t e d t h a t adding l y s i n e and  threonine.to  r o l l e d oats improved the nitrogen balance i n humans above t h a t obtained with lysine.  He obtained no f u r t h e r improvement i n n i t r o g e n balance by  f u r t h e r a d d i t i o n o f methionine.  These r e s u l t s agree w i t h the present e x p e r i -  ment which showed a marked response t o threonine when added t o b a r l e y plus lysine.  M u l l e r and Rozman (1968) showed t h a t l y s i n e , threonine o r  tryptophan  and methionine supplementation o f b a r l e y f o r g r o w i n g - f i n i s h i n g pigs improved N retained/N intake and N retained/N digested as w e l l as d a i l y gain and  69  feed e f f i c i e n c y .  This agrees w i t h the present experiment i n which adding  l y s i n e , threonine and methionine w i t h or without i s o l e u c i n e gave an improvement i n N balance, N retained/N intake percentage i n t h i s order. Bowland and Grimson (1969) i n d i c a t e d t h a t a b e t t e r N retained/N absorbed value was obtained w i t h a lysine-methionine supplemented low prot e i n d i e t (14% C P . )  than w i t h a higher p r o t e i n or an amino a c i d unsupple-  mented low p r o t e i n d i e t f o r e a r l y weaned p i g s .  There was an increase i n  d a i l y n i t r o g e n r e t e n t i o n when L - l y s i n e was added t o d i e t s containing three percent urea but t h i s d i d not occur where both L - l y s i n e and DL-methionine was added.  This observation suggested t h a t f o r pigs fed the low p r o t e i n  d i e t plus urea, methionine was not the second l i m i t i n g amino a c i d a f t e r lysine.  This agreed w i t h our experiment i n which adding methionine pro-  duced only a s l i g h t response since threonine was the second l i m i t i n g amino acid after lysine. The barley-soybean  c o n t r o l r a t i o n gave the highest N balance,  the best opponent N d i g e s t i b i l i t y and the highest value f o r N r e t a i n e d as a percentage of N intake but the second lowest value f o r b i o l o g i c a l value, a f t e r the higher l e v e l of l y s i n e .  I t appears that the N o f the b a r l e y -  soybean r a t i o n was b e t t e r digested but o f a lower b i o l o g i c a l value than the N of the l y s i n e plus threonine, l y s i n e plus threonine plus methionine and l y s i n e plus threonine plus methionine plus i s o l e u c i n e r a t i o n s . These r e s u l t s were i n agreement w i t h those of Bowland and Grimson (1969) who showed that apparent nitrogen d i g e s t i b i l i t y was low on low p r o t e i n d i e t s but increased w i t h urea o r w i t h p r o t e i n supplementation  of the low-protein  d i e t and the highest apparent b i o l o g i c a l value was obtained w i t h supplement a t i o n by l y s i n e and methionine t o low p r o t e i n d i e t .  I t i s possible that  the response t o the lower b i o l o g i c a l value of barley-soybean  control ration  70  was due t o e i t h e r a higher p r o t e i n concentration since the barley-soybean r a t i o n was about 17% crude p r o t e i n and the other r a t i o n s were about 11% o r a higher p r o t e i n intake which was approximately  one and h a l f times more  p r o t e i n than those o f the other r a t i o n s . These r e s u l t s were i n agreement w i t h Metta and M i t c h e l l (1956), and Rippon (1959) who found t h a t the b i o l o g i c a l value o f d i f f e r e n t proteins decreased l i n e a r l y as the p r o t e i n conc e n t r a t i o n o r intake increased. The r e s u l t s o f the present study showed t h a t b a r l e y p r o t e i n could be improved by supplementation w i t h f o u r amino acids.  However, barley-amino  acids r a t i o n s gave lower values f o r n i t r o g e n r e t e n t i o n than the b a r l e y soybean c o n t r o l r a t i o n .  Therefore, f u r t h e r studies might solve the problems  o f supplementation o f c e r e a l p r o t e i n s w i t h s y n t h e t i c amino acids. There was a p o s s i b i l i t y o f n i t r o g e n losses i n feces and urine. Saben and Bowland (1971) suggested t h a t e i t h e r wet o r dry p i g f e c a l m a t e r i a l may be used f o r n i t r o g e n and energy determinations i n p i g d i g e s t i o n t r i a l s where feces i s d r i e d a t 60°C f o r 72 hours.  Martin (1966) i n d i c a t e d t h a t  losses o f NHg from feces were n e g l i g i b l e and the losses from urine depended on the temperature and pH a t which i t was c o l l e c t e d . The average l o s s o f nitrogen on c o l l e c t i o n o f u r i n e a t a pH value below 2.0 was 1.33% when the ambient temperature was between 25 and 28°C and 0.97% when i t was 15 and 18°C.  I n the present experiment, urine was c o l l e c t e d i n strong s u l p h u r i c  a c i d so t h a t the pH o f u r i n e was below 2 even though samples were stored f o r q u i t e long periods i n a f r e e z e r .  Therefore losses o f nitrogen from  feces and urine would be n e g l i g i b l e i n t h i s experiment.  71  D.  CONCLUSION  The metabolism t r i a l was conducted t o determine the e f f e c t o f amino a c i d supplementation  o f Peace R i v e r b a r l e y on n i t r o g e n balance and  apparent b i o l o g i c a l value. The a d d i t i o n o f L—stysine and L-threonine t o the b a r l e y tended to improve n i t r o g e n balance when adjusted f o r feed i n t a k e , apparent nitrogen d i g e s t i b i l i t y , b i o l o g i c a l value and N retained/N intake above t h a t obtained by the a d d i t i o n o f l y s i n e alone but the d i f f e r e n c e was not s i g n i f i c a n t . Further a d d i t i o n o f methionine w i t h o r without i s o l e u c i n e markedly improved the above c r i t e r i a although not a l l improvements were s i g n i f i c a n t above the a d d i t i o n o f l y s i n e alone.  The r e s u l t s showed t h a t the major e f f e c t o f  improving p r o t e i n q u a l i t y appeared t o be due t o the threonine supplementat i o n t o the lower l e v e l o f l y s i n e since f u r t h e r supplementation  w i t h methio-  nine and w i t h o r without i s o l e u c i n e gave f u r t h e r s l i g h t l y n o n - s i g n i f i c a n t improvement i n n i t r o g e n metabolism measurements.  Whereas, i s o l e u c i n e d i d  not a f f e c t the p r o t e i n q u a l i t y so much as methionine.  Therefore,  threonine  was the second l i m i t i n g amino a c i d a f t e r l y s i n e i n t h i s experiment and methionine and I s o l e u c i n e were probably l i m i t i n g too. The d i f f e r e n c e i n apparent d i g e s t i b i l i t y o f p r o t e i n between two l e v e l s o f l y s i n e was not s i g n i f i c a n t but the b i o l o g i c a l value o f the lower l e v e l o f l y s i n e r a t i o n was s i g n i f i c a n t l y higher than t h a t o f the higher level of lysine ration.  This i n d i c a t e d t h a t N r e t e n t i o n v a r i e d w i t h the  l e v e l o f l y s i n e but N absorption was not i n f l u e n c e d by the d i f f e r e n t l y s i n e level.  Therefore, 0.75% l y s i n e seemed t o be adequate f o r growing pigs i n  t h i s experiment.  Further studies i n amino a c i d d i g e s t i b i l i t y and blood  amino a c i d patterns may e x p l a i n these r e s u l t s .  A l s o l a b e l l e d amino acids  would a i d i n determining amino a c i d absorption and"retention.  72  Supplementation w i t h l y s i n e and threonine w i t h and without methionine, and a l s o i s o l e u c i n e r e s u l t e d i n a s i g n i f i c a n t l y lower N balance, apparent N d i g e s t i b i l i t y but a s i g n i f i c a n t l y higher b i o l o g i c a l value than the barley-soybean c o n t r o l r a t i o n . I t was concluded t h a t both p r o t e i n and amino a c i d supplementation to the b a s a l r a t i o n of b a r l e y could a f f e c t n i t r o g e n balance and b i o l o g i c a l value.  E i t h e r adding n i t r o g e n or adding more threonine, or both t o the  b a r l e y may improve n i t r o g e n balance and b i o l o g i c a l value but not d i g e s t i b i l i t y .  73  V.  GENERAL CONCLUSIONS AND RECOMMENDATIONS  The supplementation w i t h 0.50% L - l y s i n e HC1 (0.75% t o t a l l y s i n e ) t o a b a s a l r a t i o n o f b a r l e y seemed t o improve p r o t e i n q u a l i t y compared t o the supplementation w i t h 0.69% L - l y s i n e HC1 (0.90% t o t a l l y s i n e ) .  The  b i o l o g i c a l value o f the lower l e v e l o f l y s i n e r a t i o n (0.75% t o t a l l y s i n e ) was s i g n i f i c a n t l y higher than t h a t o f the higher l e v e l o f l y s i n e (0.90% t o t a l l y s i n e ) , and the t r e n d showed t h a t pigs f e d the lower l y s i n e were leaner and had l a r g e r eye muscle areas than those fed t h e higher l e v e l of l y s i n e even though the lower l e v e l o f l y s i n e gave a s i g n f i c a n t l y lower growth r a t e and poorer feed e f f i c i e n c y than the h i g h e r l e v e l o f l y s i n e . Both t h e feeding experiment and n i t r o g e n balance experiment i n d i c a t e d t h a t threonine was the second l i m i t i n g amino a c i d since supplementation w i t h l y s i n e and threonine t o the b a r l e y improved growth performance s i g n i f i c a n t l y and tended t o improve n i t r o g e n r e t e n t i o n and b i o l o g i c a l value t o a greater extent than adding l y s i n e alone.  However, supplementa-  t i o n o f b a r l e y w i t h l y s i n e and threonine r e s u l t e d i n s i g n i f i c a n t l y poorer d a i l y g a i n , feed e f f i c i e n c y , carcass q u a l i t y and n i t r o g e n r e t e n t i o n but s i g n i f i c a n t l y higher b i o l o g i c a l value than the barley-soybean c o n t r o l r a t i o n . Therefore, these treatments were unable t o produce the r e s u l t s equivalent t o t h a t from normally supplemented soybean r a t i o n . The r e s u l t o f the present study showed t h a t b a r l e y p r o t e i n could be markedly improved by supplementation w i t h l y s i n e and threonine and they demonstrated the importance o f t a k i n g these i n t o account i n a r a t i o n . I t i s w e l l known t h a t one o f the r o l e s o f p r o t e i n concentrates i s t o counteract amino a c i d d e f i c i e n c i e s and t o t a l n i t r o g e n i n t h e c e r e a l components o f a r a t i o n and t h i s almost i n e v i t a b l y gives r i s e t o an excess o f the other amino acids which are not needed f o r p r o t e i n synthesis.  I n order t o reduce  74  t h i s excess as much as p o s s i b l e , i t i s necessary t o supplement these l i m i t i n g amino acids such as l y s i n e and threonine and a l s o t o have a thorough knowledge of d i e t a r y amino a c i d content and a v a i l a b i l i t y at given components.  The shortage and higher cost of p r o t e i n supplements f o r use  i n feed i s i n c r e a s i n g .  Therefore, f u r t h e r studies o f the problem r e l a t e d  t o r e p l a c i n g p r o t e i n concentrate w i t h s y n t h e t i c amino acids are required i f they can be made a v a i l a b l e at s u i t a b l e p r i c e s .  75  LITERATURE CITED Abernathy, R.P. , Sewell, R.F. and T a r p l e y , R.L. 1958. I n t e r r e l a t i o n s h i p s of p r o t e i n , l y s i n e and energy i n d i e t s f o r growing swine. J . Anim. S c i . 17, 635. A g r i c u l t u r a l Research Council. 1967. The N u t r i e n t Requirements o f Farm Livestock No. 3. Pigs. T e c h n i c a l Review and Summaries. A g r i c u l t u r a l Research C o u n c i l , London. A.O.A.C.  1960. O f f i c i a l Methods o f A n a l y s i s (9th Ed.). A s s o c i a t i o n o f O f f i c i a l A g r i c u l t u r a l Chemists, Washington, D.C.  Arker, D.C, Catron, D.V. and Hays, V.W. 1959. Lysine and methionine supplementation o f corn-soybean o i l meal r a t i o n s f o r p i g s i n dry l o t . J . Anim. S c i . 18, 1053. Ashton, G.C , K a s t e l i c , J . , A r c k e r , D.C, Jensen, A.H. , Maddock, H.H. , K l i n e , E.A. and Catron, D.V. 1955. D i f f e r e n t p r o t e i n l e v e l s w i t h and without a n t i b i o t i c s f o r growing-finishing swine: e f f e c t on carcass leaness. J . Anim. S c i . 14, 82. B a l d i n i , J.T. and Rosenberg, H.R. 1955. The e f f e c t o f productive energy l e v e l o f the d i e t on the methionine requirement o f the chick. P o u l t r y S c i . 34, 1301. B a l d i n i , J.T., Marvel, J.P. and Rosenberg, H.R. 1957. The e f f e c t o f the productive energy l e v e l o f the d i e t on the methionine r e q u i r e ment o f the p o u l t . P o u l t r y S c i . 36, 1031. B a l d i n i , J.T. and Rosenberg, H.R. 1957. The e f f e c t o f c a l o r i e source i n a chick d i e t on growth, feed u t i l i z a t i o n , and body composition. P o u l t r y S c i . 36, 432. Barber, R.S., Braude, R. and M i t c h e l l , K.G. 1969. Di-ammonium phosphate as a source o f n i t r o g e n i n a l l - c e r e a l d i e t s f o r growing p i g s . Anim. Prod. 11, 292. Barnes, R.H. and Bosshardt, D.K. 1946. The e v a l u a t i o n o f the p r o t e i n q u a l i t y i n the normal animal. Ann. N.Y. Acad. S c i . 48, 273. Bayley, H.S. and Summer, J.D. 1968. E f f e c t o f p r o t e i n l e v e l and l y s i n e and methionine supplementation on the performance o f growing p i g s : Response o f d i f f e r e n t sexes and s t r a i n s o f p i g s . Can. J . Anim. S c i . 48, 181. Beames, R.M., D a n i e l s , L.J. and Sewell, J.O. 1968. The t o t a l replacement of p r o t e i n supplements by s y n t h e t i c l y s i n e i n r a t i o n s based on sorghum g r a i n f o r p i g s over 45 kg liveweight. Proc. Aust. Soc. Anim. Prod. 7, 391. Beames, R.M. and Pepper, P.M. 1969. The p a r t i a l replacement o f soybean meal amino a c i d i n p i g r a t i o n s based on wheat and sorghum. Aust. J . Exp. Agr. Anim. Husb. 9, 400.  76  Becker, D.E. 1959. Balancing swine r a t i o n s . of A g r i . , C i r c . 811.  University of I l l i n o i s , Coll.  Becker, D.E., Adams, C.R., T e r r i l l , S.W. and Meade, R.T. 1953. The influence o f heat treatment and solvent upon the n u t r i t i v e value of soybean o i l meal f o r swine. J . Anim. S c i . 12, 107. Becker, D.E., Adams, C.R., T e r r i l l , S.W. and Meade, R.J. 1955. The methion i n e - c y s t i n e need o f the young p i g ? . J . Anim. S c i . 14, 1086. Becker, D.E., Jensen, A.H. and Harmon, B.G. 1963. Balancing swine r a t i o n s . U n i v e r s i t y o f I l l i n o i s , C o l l . o f Agr. C i r . 866. Becker, D.E., Jensen, A.H. and Harmon, B.G. 111. Agr. Exp. Sta. C i r . 866.  1966. Balancing swine r a t i o n s .  Becker, D.E. , L a s s i t e r , J.W. , T e r r i l l , S.W. and Norton, H.W. 1954a. Levels of p r o t e i n i n p r a c t i c a l r a t i o n s f o r the p i g . J . Anim. S c i . 13, 611. Becker, D.E. , N o t z o l t , R.A., Jensen, A.H., T e r r i l l , S.W. and Norton, H.W. 1955. The tryptophan requirement o f the young p i g . J . Anim. S c i . 14, 664. Becker, D.E. , U l l r e y , D.E. and T e r r i l l , S.W. 1954b. P r o t e i n and amino a c i d intakes f o r optimum growth r a t e i n the young p i g . J . Anim. S c i . 13, 346. Beeson, W.M. , Jackson, H.D. and Mertz, E.T. 1953. Quantitative threonine requirement o f the weanling p i g . J . Anim. S c i . 12, 870. Beeson, W.M. , Mertz, E.T. and Shelton, D.C. 1948. The amino a c i d r e q u i r e ment o f swine. 1, tryptophan. Science, 107, 599. Beeson, W.M., Mertz, E.T. and Shelton, D.C. 1949. E f f e c t o f tryptophan d e f i c i e n c y i n the p i g . J . Anim. S c i . 8, 532. B e l l , J.M. 1965. N u t r i e n t requirements o f Canadian Yorkshire swine. V. A study o f the l y s i n e and p r o t e i n requirement o f f i n i s h i n g pigs weighing from 100 t o 200 pounds. Can. J . Anim. S c i . 45, 105. B e l l , EF.M. and Voldeng, L.O. 1968. Further observations on l y s i n e and prot e i n requirements o f 23 t o 89 kg p i g s . Can. J . Anim. S c i . 48, 251. B e l l , J.M. , W i l l i a m , H.H., L o o s l i , J.K. and Maynard, L.A. 1950. The e f f e c t of methionine supplementation o f a soybean o i l meal p u r i f i e d r a t i o n f o r growing p i g s . J . N u t r i t i o n . 40, 551. Benton, D.A., Harper, A.E. , Spivey, H.E. and Elvehjem, C.A. 1956. Leucine, i s o l e u c i n e and v a l i n e r e l a t i o n s h i p i n the r a t . Archs. Biochem. Biophys. 60, 147. Berry, T.H., Becker, D.E., Rasmussen, O.G. , Jensen, A.H. and Norton, H.W. 1962. The l i m i t i n g amino a c i d i n soy-protein. J . Anim. S c i . 21, 558.  77 Berry, T.H., Combs, G.E., Wallace, H.D. and Robbins, R.C. 1966. Response o f the growing p i g t o a l t e r a t i o n s i n the amino a c i d pattern o f i s o l a t e d soybean p r o t e i n . J . Anim. S c i . 25, 722. B l a i r , R. , Dent, J.B. , E n g l i s h , P.R. and Raebum, J.R. 1969. P r o t e i n , l y s i n e and feed intake l e v e l e f f e c t s on p i g growth. 1. Main e f f e c t s . J . Agr. S c i . Camb. 72, 379. Block, R.J. and M i t c h e l l , H.H. 1946. The c o r r e l a t i o n o f the amino a c i d composition o f p r o t e i n w i t h t h e i r n u t r i t i v e value. Nut. Abst. and Revs. XVI, 249. Boomgaard, J . and Backer, D.H. 1970. The l y s i n e requirement o f the chick at f i v e p r o t e i n l e v e l s . Poul. S c i . 49, 1369. Boomgaard, J . and Backer, D.H. 1971. Tryptophan requirement o f growing chicks as a f f e c t e d by d i e t a r y p r o t e i n l e v e l . J . Anim. S c i . 33, 595. Bowland, J.P. 1962. A d d i t i o n o f l y s i n e and/or a t r a n q u i l i z e r t o low prot e i n , soybean meal supplemented r a t i o n f o r growing bacon p i g s . J . Anim. S c i . 21, 852. Bowland, J.P. and Berg, R.T. 1959. Influence o f s t r a i n and sex on the r e l a t i o n s h i p o f p r o t e i n t o energy i n the r a t i o n s o f growing and f i n i s h i n g bacon p i g s . Can. J . Anim. S c i . 39, 102. Bowland, J.P. and Grimson, R.E. 1969. Lysine and methionine supplementat i o n o f swine and r a t d i e t s containing up t o three percent urea. Wissen s c h a f t l i c h e Z e i t s c h r i f t der U n i v e r s i t a t Rostock. T e i l I I , p. 213. Braude, R. and Lerman, P. 1970. P r o t e i n and l y s i n e l e v e l s i n p r a c t i c a l r a t i o n s . J . Agr. S c i . Camb. 74, 575. Braude, R., M i t c h e l l , K.G., Myres, A.W. and Newport, M.J. 1972. The replacement o f p r o t e i n concentrates by s y n t h e t i c l y s i n e i n the d i e t o f growing p i g s . Br. J . N u t r i t i o n " 27, 169. Bravo, F.O., Meade, R.J., Stockland, W.L. and Nordstrom, J.W. 1970. Reevaluation o f the i s o l e u c i n e requirement o f the growing pig-plasma free i s o l e u c i n e as a response c r i t e r i o n . J . Anim. S c i . 31, 1137. Brinegar, M.J., L o o s l i , J.K., Maynard, L.A. and W i l l i a m s , H.H. 1950c. The i s o l e u c i n e requirement f o r the growth o f swine. J . N u t r i t i o n 42, 619. Brinegar, M.J. , L o o s l i , J.K., W i l l i a m s , H.H. and Maynard, L.A. 1949. Lysine requirement f o r growing p i g s . Fed. Proc. 8, 379. Brinegar, M.J. , W i l l i a m s , H.H., F e r r i s , F.H., L o o s l i , J.K. and Maynard, L.A. 1950a. The l y s i n e requirement f o r the growth o f swine. J . Nutr. 42, 129.  78 Brinegar, M.J. , W i l l i a m s , H.H., F e r r i s , F.H., L o o s l i , J.K. and Maynard, L.A. 1950b. Lysine requirement f o r growing swine. Fed. Am. Soc. E x p t l . B i o l . 9, 353. Brooks, C.C. and Thomas, H.R. 1959. Supplements t o peanut o i l meal p r o t e i n f o r growing f a t t e n i n g swine. J . Anim. S c i . 18, 1119. Buck, S.F., H a r r i n g t o n , G. and Johnson, R.F. 1962. The p r e d i c t i o n o f lean percentage o f p i g s o f bacon weight from carcass measurements. Anim. Prod. 4, 25. C a h i l l y J r . , G.M. , M i l l e r , R.F., K e l l y , R.F. and Brooks, C.C. 1963. E f f e c t o f various l e v e l s o f d i e t a r y l y s i n e on c e r t a i n blood phenomena, muscle development, and muscle-protein b i o l o g i c a l value o f growi n g swine. J . Anim. S c i . 22, 726. Calhoun, W.K., Hephurn, F.N. and Bradley, W.D. 1960. The a v a i l a b i l i t y o f l y s i n e i n wheat, f l o u r , bread and gluten. J . Nutr. 70, 337. Carpenter, K.J. food.  1960. The estimation o f a v a i l a b l e l y s i n e i n animal p r o t e i n Biochem. J . 77, 604.  Catron, D.V., A r k e r , D.C, Ashton, G.C , Maddock, H.M. and Speer, V.C. 1953. Lysine and/or methionine supplementation o f corn-soybean o i l meal r a t i o n s f o r p i g s i n dry l o t . J . Anim. S c i . 12, 910. Change, R.E. , Germann, A.F.O., Beeson, W.M. and Mertz, E.T. 1958. E f f e c t o f p r o t e i n l e v e l on the l y s i n e requirement o f weanling p i g s . J . Anim. S c i . 17, 1161. Clausen, e t a l . 1959, 1960, 1961, 1962, 1963 and 1964. Experiments w i t h p i g s . Reports a t annual meeting o f the N a t i o n a l Research I n s t i t u t i o n o f Animal Husbandry, Copenhagen, Clawson, A.J. 19.67. Influence o f p r o t e i n l e v e l , amino a c i d r a t i o n and c a l o r i c density o f the d i e t on feed intake and performance o f pigs. J . Anim. S c i . 26, 328. C u r t i n , L.V., Abraham, J . , W i l l i a m s , H.H., L o o s l i , J.K. and Maynard, L.A. 1952c. Estimation o f amino a c i d requirements o f swine from t i s s u e a n a l y s i s . Fed. Proc. 11, 439. C u r t i n , L.V. , L o o s l i , J.K. , Abraham, J . , W i l l i a m s , H.H. and Maynard, L.A. 1952b. The methionine requirement f o r the growth o f swine. J . Nutr. 48, 499. C u r t i n , L.V., L o o s l i , J.K. , W i l l i a m s , J.P. and W i l l i a m s , H.H. 1952a. Methionine as a supplement t o soybean o i l meal f o r weanling p i g s . J . Anim. S c i . 11, 459. Deshpande, P.D., Harper, A.E. and Elvehjem, C.A. 1958. Amino a c i d imbalance on low f i b r e d i e t s . J . B i o l . Chem. 230, 327. Duncan, D.B.  1955. M u l t i p l e range and m u l t i p l e F t e s t s .  Biometrics 11, 1.  79 D'Mello, J.P.F. and Lewis, D. 1970a. Amino a c i d i n t e r a c t i o n i n chick n u t r i t i o n . I . The i n t e r r e l a t i o n s h i p between l y s i n e and arginine. Br. Poult. S c i . 11, 299. D'Mello, J.P.F. and Lewis, D. 1970b. Amino a c i d i n t e r a c t i o n i n chick n u t r i t i o n . 2. The i n t e r r e l a t i o n s h i p between l e u c i n e , i s o l e u c i n e and v a l i n e . Br. Poult. S c i . 11, 313. D'Mello, J.P.F. and Lewis, D. • 1970c. Amino a c i d i n t e r a c t i o n i n chick n u t r i t i o n . 3. The interdependence i n amino a c i d requirements. Br. Poult. S c i . 11, 367. E r i c s o n , L.E. , Larsson, S. and Ostholm, CO. 1962. Preliminary studies on the p o s s i b i l i t y o f improving the p r o t e i n value o f cereals f o r swine by l y s i n e supplementation. Acta. Agr. Scandinavica 12, 157. Evans, R.E. 1958. N u t r i t i o n o f bacon p i g . XIX. The requirement o f the bacon p i g f o r c e r t a i n e s s e n t i a l amino acids. J . Agr. S c i . 58, 230. Evans, R.E. 1960. The e f f e c t o f adding l y s i n e and methionine t o the d i e t o f pigs kept on low-protein vegetable foods. J . A g r i . S c i . Camb. 54, 266. Evans, R.E. 1962. The i s o l e u c i n e requirement o f the weanling p i g s . J . Agr. S c i . Camb. 58, 413. Evans, R.E. 1963. The threonine requirement o f the weanling p i g s . S c i . Camb. 60, 259.  J . Agr.  F l o r e n t i n o , R.F. and Pearson, W.N. 1962. E f f e c t o f threonine-induced amino a c i d imbalance on the e x c r e t i o n o f tryptophan metabolites by the r a t . J . Nutr. 78, 101. Frape, D.L., Wolf, K.L., Wilkinson, J . and Cubb, L.G. 1968. M o d i f i c a t i o n t o S h i n f i e l d metabolism crate. J . I n s t . Animal Tech. 19, 61. Grau, C.R.  1948. E f f e c t o f p r o t e i n l e v e l on the l y s i n e requirement o f the chick. J . Nutr. 36, 99.  Grau, C.R. and C a r r o l l , R.W. 1958. Evaluation o f p r o t e i n q u a l i t y i n processed p l a n t p r o t e i n f o o d s t u f f s . 153-189. A.M. A l t s c h u l ( e d i t o r ) . Academic Press, New York. Harper, A.E. 1958. Balance and imbalance o f amino acids. S c i . 69, 1025.  Ann. N.Y. Acad.  Harper, A.E. 1959. Advances i n our knowledge o f p r o t e i n and amino a c i d requirements. Feb. Proc. Supplement. No. 3 Part I I , 104. Harper, A.E. , Benton, D.A. , Wineje, M.E. and Elvehjem, C.A. 1954. Leucinei s o l e u c i n e antagonism i n the r a t . Archs. Biochem. Biophys. 51, 523. Harper, A.E. and Kumta, U.S. 1959. Amino a c i d balance and p r o t e i n r e q u i r e ment. Feb. Proc. 18, 1136.  80  Harvey, W.R. 1960. Least-squares analysis o f data w i t h unequal sub-class numbers. ARS 20-8, United States Department o f A g r i c u l t u r e . Henry, Y.  1968. E f f e c t o f varying l e v e l s o f c e l l u l o s e o r n o n - n u t r i t i v e d i l u e n t i n the d i e t on growth performance o f the p i g and n u t r i e n t d i g e s t i b i l i t y . Proc. 2nd World Conf. Anim. Prod., Maryland.  Hegsted, D.M. , Briggs', G.M. , Elvehjem, C.A. and H a r t , E.B. 1941. The r o l e s of arginine and g l y c i n e i n chick n u t r i t i o n . J . B i o l . Chem 140, 191. H i l l , R.L. 1965. Hydrolysis o f p r o t e i n s . Homb, H.  Advan. P r o t e i n Chem. 20, 37.  1963. Amino acids i n p i g n u t r i t i o n (a review). Norges Landbrukhojskole 42, 20.  Meldinger f r a  Hutchinson, H.D., Jensen, A.H., T e r r i l l , S.W. and Becker, D.E. 1957. The l y s i n e requirement o f weanling p i g s . J . Anim. S c i . 16 , 558. Jensen, A.H., Becker, D.E. and Harmon, B.G. 1965i N u t r i t i o n a l adequacy o f milo f o r the f i n i s h i n g p i g . J . Anim. S c i . 24, 398. Jones, J.D. 1964. Lysine-arginine antogonism i n the chick. 313.  J . Nutr. 84,  K e i t h , M.O. , Christensen, D.A. and Owen, B.D. 1972. Determination o f the methionine requirement o f growing, pigs u s i n g serum freev';amino acids. Can. J . Anim. S c i . 52, 163. Kohler, G.O. and P a l t e r , R.. 1967. Studies on methods f o r amino a c i d a n a l y s i s of wheat products. Cereal Chem. 44, 512. Kroening, G.H., Pond, W.G. and L o o s l i , J.K. 1962. Methionine requirement of the s u c k l i n g age p i g . Summary o f Research Swine D i v i s i o n , Dept. Animal Husbandry, C o r n e l l U n i v e r s i t y . Lawrence, T.L.J. 1971. H i g h - l e v e l c e r e a l d i e t s f o r the growing/finishing pig. V. A comparison o f f i n i s h e r d i e t s containing high l e v e l o f maize o f b a r l e y w i t h wide o r narrow c a l o r i e / p r o t e i n / l y s i n e r a t i o n s when f e d t o give two d i f f e r e n t c a l o r i e intakes. J . Agr. S c i . Camb. 76, 443. Luecke, R.W., M c M i l l e n , W.N. , Throp, F. and T u l l , C. 1946. The supplementary e f f e c t o f tryptophan and n i c o t i n i c a c i d i n low p r o t e i n r a t i o s f o r weanling p i g s . J . Anim. S c i . 5, 408. Marcum, J.B. and S t o u f f e r , J.R. 1961. R e l a t i o n s h i p o f l o i n i n d i c e s t o pork carcass meatiness. J . Anim. S c i . 20, 919. M a r t i n , A.K. 1966. Some e r r o r s i n the determination o f nitrogen r e t e n t i o n of sheep by nitrogen balance studies. Br. J . Nutr. 20, 325. McWard, G.W. , Becker, D.E], Norton, H.W., T e r r i l l , S.W. and Jensen, A.H. 1959. The l y s i n e requirement o f weanling swine a t two l e v e l s o f d i e t a r y p r o t e i n . J . Anim. S c i . 18, 1059.  81  Meade, R.J. 1956. The influence o f tryptophan, methionine and l y s i n e supplementation o f a corn-soybean o i l meal d i e t on n i t r o g e n balance o f growing swine. J . Anim. S c i . 15 , 288. Meade, R.J., Dukelow, W.R. and Grant, R.S. 1966. Lysine and methionine a d d i t i o n t o corn-soybean o i l meal d i e t s f o r growing swine: e f f e c t s on rate and e f f i c i e n c y o f gain and carcass characteri s t i c s . J . Anim. S c i . 25, 78. Mertz, E. T., Beeson, W.M. and Jackson, H.D. 1952. C l a s s i f i c a t i o n o f e s s e n t i a l amino acids f o r the weanling p i g . Arch. Biochem. 38, 121. Mertz, E.T., Delong, D.C., Thrasher, D.M. and Beeson, W.M. 1955. H i s t i d i n e and leucine requirements o f the weanling p i g . J . Anim. 14, 1217. Mertz, E.T., Shelton, D.C. and Beeson, W.M. 1949. The amino a c i d r e q u i r e ment o f swine: l y s i n e . J . Anim. S c i . 8,524. Metta, V.C. and M i t c h e l l , H.H. 1956. A comparison o f the b i o l o g i c a l values o f d i e t a r y p r o t e i n incorporated i n h i g h - f a t and low-fat d i e t s . J . Nutr. 59, 501. M i t c h e l l , H.H. 1949. Adult growth i n man and i t s n u t r i e n t requirements. Arch. Biochem. 21, 335. M i t c h e l l , H.H. 1959. Differences i n amino a c i d requirements. I n P r o t e i n and Amino A c i d N u t r i t i o n . E d i t . A.A. Albanese, Academic Press. M i t c h e l l , J.R., Becker, D.E., Jensen, A.H., Norton, H.W., and Harmon, B.G. 1965. C a l o r i c density o f the d i e t and the l y s i n e need o f young swine. J . Anim. S c i . 24, 997. M i t c h e l l , H.H., Hamilton, T.S., Beadles, J.R. and Simpson, F. 1945. The importance o f commercial processing f o r the p r o t e i n value o f food products. J . Nutr. 29, 13. Moore, S.  1963. On the determination o f c y s t i n e as c y s t e i c a c i d . Chem. 238, 235.  J. Biol.  Moran, E.T., J r . , Jensen, L.S. and McGinnis, J . 1963. Dye b i n d i n g by soybean and f i s h meal as an index o f q u a l i t y . J . Nutr. 79, 239. Morrison, M.A. and Harper, A.E. 1960. Amino a c i d balance and imbalance. i v . S p e c i f i t y o f threonine i n producing an imbalance i n d i e t s d e f i c i e n t i n n i a c i n and tryptophan. J . Nutr. 71, 296. Morrison, A.E., Middleton, E.J. and Mclaughlen, J.M. 1961. Blood amino a c i d studies. I I . E f f e c t o f d i e t a r y l y s i n e concentration, sex and growth rate on plasma free l y s i n e and threonine l e v e l i n the r a t . Can. J . Biochem. P h y s i o l . 39, 1675. M u l l e r , Z., K o z e l , V., H e j z l a r , Z., Bauer, B. and Moravec, J . 1967a. Lysine i n combination w i t h another l i m i t i n g amino a c i d i n the n u t r i t i o n o f weaned p i g l e t s . B i o l o g i z a c Chem. Vyzivy Z v i r a t 3, 411.  82 M u l l e r , Z., K o z e l , V., Bauer, B., Strunc, M. and Moravec, J . 1967c. Enrichment o f c e r e a l d i e t s f o r f a t t e n i n g pigs from 35 kg l i v e weight w i t h l y s i n e , threonine, tryptophan and methionine. Biol. Chem. Vyzivy Z v i r a t 5, 399. M u l l e r , Z. and Malek, I . 1967a. Monodiet based on wheat f o r weaned p i g l e t s . B i o l . Chem. Vyzivy Z v i r a t 3, 535. M u l l e r , Z. and Malek, I . 1967b. Monodiet based on b a r l e y f o r weaned p i g l e t s . B i o l . Chem. Vyzivy Z v i r a t 3, 543. M u l l e r , Z. and Malek, I . 1967c. Monodiet based on maize f o r weaned p i g l e t s . B i o l . Chem. Vyzivy Z v i r a t 3, 551. M u l l e r , Z., Palkoska, J . , Drevjany, L. and Moravec, J . 1967b. Cereal . d i e t s enriched w i t h l y s i n e , threonine, tryptophan and methionine i n the n u t r i t i o n o f weaned p i g l e t s . B i o l . Chem. Vyzivy Z v i r a t 3, 423. M u l l e r , Z. and Rozman, J . 1968. Monocereal d i e t s f o r t i f i e d w i t h l y s i n e , threonine, tryptophan and methionine i n p i g f a t t e n i n g . B i o l . Chem. Vyzivy Z v i r a t 4, 433. N a t i o n a l Academy o f Science-National Research Council. 1968. N u t r i e n t requirement o f domestic animals. 2. N u t r i e n t Requirement o f Swine. 6th ed. Publ. 1599, Washington, D.C. Newell, J.A. and Bowland, J.P. 1972. Performance, carcass composition, and f a t composition o f boars, g i l t s and barrows fed two l e v e l s o f p r o t e i n . Can. J . Anim. S c i . 52, 543. N i e l s e n , A.J. 1971. The d i g e s t i b i l i t y o f amino a c i d d i f f e r e n t balanced feed r a t i o n s as r e l a t e d t o the d i g e s t i b i l i t y o f nitrogen i n growing p i g s . Acta. Agr. Scandinavia 21, 189. N i e l s e n , H.E., Hays, V.W., Speer, V.C. and Catron, D.V. 1963. Lysine supplementation o f corn- and barley-base d i e t s f o r growingf i n i s h i n g swine. J . Anim. S c i . 22, 454. Oestemer, G.A. , Meade, R.J., Stockland, W.L. and Hanson, L.E. 1970. Methionine supplementation t o opaque-2 corns. J . Anim. S c i . 31, 1133. Oh, S. , Summer, J.D. and Wood, A.S. 1972. A v a i l a b i l i t y o f methionine i n various p r o t e i n supplements as determined by chick bioassay. Can. J . Anim. S c i . 52, 171. Osborne, T.B. and Mendel, L.B. 1920. N u t r i t i v e value o f the p r o t e i n o f the b a r l e y , o a t , rye and wheat k e r n e l s . J . B i o l . Chem. 41, 275. Osborne, T.B. and Mendel, L.B. 1919. A method o f expressing numerically the growth-promoting value o f p r o t e i n s . J . B i o l . Chem. 37, 223.  83 Oser, B.L. 1951. Method f o r i n t e g r a t i n g e s s e n t i a l amino a c i d content i n the n u t r i t i o n a l evaluation o f p r o t e i n . J . Amer. C i e t e t i c Assn. 27, 396. Ostrowski, H. 1969. The e f f e c t s o f d i e t a r y supplementation w i t h l y s i n e and methionine on body and t i s s u e composition i n the p i g . Anim. Prod. 11, 521. O'Dell, B.L., Laerdal, O.A., J e f f a y , A.M. and Savage, J.E. 1958. metabolism i n the growing chiek. Poult. S c i . 37, 817.  Arginine  Pecora, L.J. and Hundley, J.H. 1951. N u t r i t i o n a l improvement o f white p o l i s h e d r i c e by the a d d i t i o n o f l y s i n e and threonine. J . Nutr. 44, 101. Pfander, W.H. and T r i b b l e , L.F. 1953. The e f f e c t o f supplementing p r a c t i c a l r a t i o n f o r weanling pigs with l y s i n e and methionine. J . Anim. S c i . 12, 927. P i c k , R.T. and Meade, R.T. 1971. Amino a c i d supplementation o f opaque-2 corn d i e t s f o r growing r a t s . J . Nutr. 101, 1241. P i e r c e , A.B. and Bowland, J.P. 1972. P r o t e i n amino a c i d l e v e l s and sequence i n swine d i e t s e f f e c t s on gain feed conversion and carcass characteri s t i c s . Can. J . Anim. S c i . 52, 531. P i e z , K. and M o r r i s , L.A. 1960. A modified procedure f o r the automatic a n a l y s i s o f amino acids. Anal. Biochem. 1, 187. Pond, W.G., H i l l i e r , J.C. and Benton, D.A. 1958. The amino a c i d adequacy of milo f o r the growth o f r a t s . J . Nutr. 65, 493. Powick, W.E., E l l i s , N.R. and Dale, C.N. 1948. Relationship o f tryptophan t o n i c o t i n i c a c i d i n the feeding o f growing pigs. J . Anim. S c i . 7, 228. Record o f Performance f o r Swine. 1967. Production and Marketing Branch. Can. Dept. Agr. Ottawa. Rippon, W.P. 1959. Some e r r o r s i n the determination o f nitrogen r e t e n t i o n of sheep by nitrogen balance studies. B r i t . J . Nutr. 13, 243. Robinson, D.W. and Lewis, D. 1964. P r o t e i n and energy n u t r i t i o n and energy l e v e l s i n the d i e t o f f i n i s h i n g pigs. I I . The e f f e c t o f varying the p r o t e i n and energy l e v e l s i n the d i e t s o f f i n i s h i n g p i g s . J . Agr. S c i . Camb. 63, 185. Robinson, D.W. and Lewis, D. 1963. Amino-acid supplementation o f a barley r a t i o n f o r the p i g . J . S c i . Fd. Agr. 14, 806. Rogers, Q.R., Tannous, R.I. and Harper, A.E. 1967. E f f e c t s o f excess leucine on growth and food s e l e c t i o n . J . Nutr. 91, 561. Rose, W.C.  1938. The n u t r i t i v e s i g n i f i c a n c e o f the amino acids. Reviews 18, 109.  Physiol.  84  Rosenberg, H.R. 1959. Amino a c i d supplementation o f foods and feeds. In P r o t e i n and Amino A c i d N u t r i t i o n . E d i t . A.A. Albanese, Academic P r e s s , New York. Rosenberg, H.R. and B a l d i n i , J.T., Sunde, M.L., B i r d , H.R. and Runnels, T.D. 1955. The concomitant o f f a t and methionine i n b r o i l e r d i e t s . P o u l t . S c i . 34, 1308. Rosenberg, H.R. and C u l i k , R. 1955. Lysine requirement o f the growing r a t as a f u n c t i o n o f the productive energy l e v e l o f the d i e t . J . Anim. S c i . 14, 1221. Rosenberg, H.R., C u l i k , R. and E c k e r t , R.E. 1959. Lysine and threonine supplementation o f r i c e . J . Nutr. 69, 217. Rosenberg, H.R. and Rohdenburg, E.L. 1952. The f o r t i f i c a t i o n of bread w i t h l y s i n e . I I . The n u t r i t i o n a l value o f f o r t i f i e d bread. Arch. Biochem. Biophys. 37, 461. Rozman, I . , M u l l e r , Z. , Plocek, F. and S i l e r , R. 1968. The influence o f l y s i n e , threonine, tryptophan and methionine supplemented t o pigs f e d c e r e a l d i e t without p r o t e i n feeds. B i o l . Chem. Vyzivy Z v i r a t 4, 441. Saben, H.S. and Bowland, J.P. 1971. Comparative e v a l u a t i o n of some techniques used i n determination o f n i t r o g e n and energy content o f feces from p i g s . Can. J . Anim. S c i . 51, 793. Salmon, W.D. 1954. The tryptophan requirement o f the r a t as a f f e c t e d by n i a c i n and l e v e l o f d i e t a r y nitrogen. Archs. Biochem. Biophys. 51, 30. Sewell, R.F., Abernathy, R.P. and Tarpley, R.L. 1956. Interrelationship o f p r o t e i n , l y s i n e and energy i n d i e t s f o r growing swine. J . Anim. S c i . 15, 1233. f'  Sewell, R.F. and Keen, B.C. 1958. Methionine and a n t i b i o t i c s supplementat i o n f o r growing swine a t three p r o t e i n l e v e l s . J . Ahim. S c i . 17, 353. Sewell, R.F., L o o s l i , J.K., Maynard, L.A., W i l l i a m s , H.H. and Sheffy, B.E. 1952. The q u a n t i t a t i v e threonine requirement o f s u c k l i n g p i g . J . Nutr. 49, 435. *. Sewell, R.F., Thomas, M.C. and P r i c e , D. 1961. Protein-energy r e l a t i o n ship i n the r a t i o n s o f early-weaned p i g . J.Anim. S c i . 20, 820. Shelton, D.C., Beeson, W.M. and Mertz, E.T. 1951a. The e f f e c t o f methionine and c y s t i n e on the growth o f weanling p i g s . J . Anim. S c i . 10, 57. Shelton, D.C, Beeson, W.M. and Mertz, E.T. 1951b. Quantitative DL-tryptophan requirement o f the weanling p i g . J . Anim. S c i . 10, 73.  85 Shelton, D.C, Beeson, W.M. and Mertz, E.T. 1950c. Growth o f weanling p i g s on a d i e t c o n t a i n i n g ten p u r i f i e d amino acids. Arch. Biochem. Biophys. 29, 446. Smith, G.H. and Lewis, D. 1966. A r g i n i n e i n p o u l t r y n u t r i t i o n 3. Agent and t a r g e t i n amino a c i d i n t e r a c t i o n . Br. J . Nutr. 20, 621. Solberg, J . 1971. E f f e c t s o f moderate l y s i n e d e f i c i e n c y on d i g e s t i b i l i t y and metabolisable energy d i e t s and on n i t r o g e n r e t e n t i o n and u r i c a c i d e x c r e t i o n i n chicks. Acta. Agr. Scandinavia. 21, 193. Spies, J.R. 1968. Determination o f tryptophan i n corn. 16, 514.  Agr. Food Chem.  Stevenson, J.W., Davey, R.T. and H i n e r , R.L. 1960. Some e f f e c t s o f d i e t a r y l e v e l s o f p r o t e i n and a l f a l f a meal and a n t i b i o t i c supplementation on growth, feed e f f i c i e n c y and carcass c h a r a c t e r i s t i c s i n swine. J . Anim. S c i . 19, 887. Sure, B.  1954. P r o t e i n supplemenation-relative n u t r i t i v e values o f p r o t e i n i n whole wheat and whole rye and e f f e c t o f amino a c i d supplements. J . Agr. Food Chem. 2, 1108.  Tjong-A-Hung, A.R., Hanson, L.E., Rust, J.W. and Meade, R.J. 1972. E f f e c t s of p r o t e i n l e v e l sequence and sex on r a t e and e f f i c i e n c y o f gain of growing swine, and on carcass c h a r a c t e r i s i t c s , i n c l u d i n g comp o s i t i o n o f lean t i s s u e . J . Anim. S c i . 35, 760. Thomas, K. 1909. Uber d i e b i o l o g i s c h e W e r t i g k e i t der S t i c k s t o f f substanzen i n Verschiedenon Nahrimgsmitteln c i t e d i n "method o f measuring the n u t r i t i v e value o f p r o t e i n " D.V. F r o s t (ads. A.A. Abanese p r o t e i n and amino a c i d n u t r i t i o n . 1949. Academic P r e s s , New York and London. Arch. Anat.. P h y s i o l . Abt. 21 ). l  Van Loen, A. 1966. Amino acids i n animal n u t r i t i o n . Mines, Heerlen, Holland.  2 1 . Dutch State  Van Soest, P.J. 1963. Use o f detergents i n the a n a l y s i s o f f i b r o u s feed. I I . A r a p i d method f o r the determination o f f i b r e and l i g n i n . J.A.O.A.C. 46, 829. Waddel, J .  1958. I n "Processed p l a n t p r o t e i n f o o d s t u f f " . ed., p. 307-351. Academic p r e s s , New York.  A.M. A l t s c h u l ,  Whitehair, C.K. and Macvicar, K. 1952. The value o f amino a c i d supplemented t o a low p r o t e i n ; a l l - p l a n t r a t i o n f o r swine. Oklahoma Agr. Exp. Sta. Misc. Publ. 27. W i l l i a m s , M.A. and Grau, C.R. 1956. Food intake and u t i l i z a t i o n o f l y s i n e d e f i c i e n t p r o t e i n by chick i n r e l a t i o n t o the d i g e s t i b l e energy concentration o f the d i e t . J . Nutr. 59, 243. Wong, W.C, Bcylan^j W.J. and S t o t h e r s , S.C 1968. E f f e c t s o f d i e t a r y p r o t e i n l e v e l and sex on swine performance and carcass t r a i t s . Can. J . Anim. S c i . 48, 383.  86 APPENDIX Table  Page  IA.  Average d a i l y body weight gain (kg) o f the 107 pigs  87  IB.  A n a l y s i s o f variance o f the average d a i l y body weight gain o f 107 p i g s . (Covariable s t a r t i n g weight)  87  IIA.  IIB. IIIA. IIIB.  Average feed intake (kg) per p i g per day f o r each ration  88  A n a l y s i s variance o f average d a i l y feed intake  88  Average feed conversion e f f i c i e n c y r a t i o per p i g . (D.M. feed intake (kg)/weight gain (kg))  89  A n a l y s i s of variance o f feed conversion e f f i c i e n c y ration  .89  IVA.  Minimum middle f a t (mm)  90  IVB.  A n a l y s i s o f variance o f minimum middle f a t 2  90  VA.  Eye muscle (width x depth) (mm  91  VB.  A n a l y s i s of variance o f eye muscle (width x depth)  ) o f the 103 pigs . . .~ . .  .91  VIA.  Nitrogen r e t e n t i o n (g/week)  92  VIB.  A n a l y s i s o f variance f o r n i t r o g e n r e t e n t i o n  92  VIC.  A n a l y s i s o f co-variance f o r nitrogen r e t e n t i o n w i t h feed intake as the covariable A n a l y s i s o f co-variance f o r n i t r o g e n r e t e n t i o n  93  w i t h n i t r o g e n intake as the covariable  93  VILA.  Nitrogen r e t a i n e d as a percentage o f n i t r o g e n intake  94  VIIB.  A n a l y s i s o f variance f o r nitrogen r e t a i n e d as a  VID..  percentage of n i t r o g e n intake  94  VIIIA.  Apparent n i t r o g e n d i g e s t i b i l i t y (%)  95  VIIIB.  A n a l y s i s o f variance f o r apparent n i t r o g e n digestibility  IXA.  Nitrogen r e t a i n e d as a percentage o f nitrogen absorbed  IXB.  A n a l y s i s of variance f o r nitrogen r e t a i n e d as a percentage of n i t r o g e n absorbed  95 ....  96 96  87  Table IA. Average d a i l y body weight gain (kg) o f the 107 p i g s .  Treatment  Rep 1 Male Female  Rep 2 Male Female  Rep 3 Male Female  1.  Barley + Soybean (Control)  0.78 0.70 0.61  0.56 0.62  0.61 0.65 0.37  6.0 0.65 0.62  0.60 0.45 0.66  0.63 0.64 0.62  2.  Barley + L - l y s i n e HC1 (0.9% t o t a l l y s i n e )  0.50 0.44 0.52  0.50 0.46 0.39  0.45 0.50 0.53  0.41 0.51 0.41  0.47 0.53 0.35  0.51 0.41 0.37  3.  Barley + L - l y s i n e HC1 (0.75% t o t a l l y s i n e )  0.46 0.47 0.44  0.24 0.42 0.44  0.44 0.54 0.5.0  0.43 0.32 0.39  0.40 0.56 0.46  0.35 0.33 0.32  4.  Treatment 3 + 0.05% L-threonine  0.58 0.56 0.57  0.44 0.56 0.46  0.56 0.54 0.50  0.51 0.57 0.41  0.55 0.56 0.56  0.49 0.49 0.59  5.  Treatment 4 + 0.10% DL-methionine  0.39 0.62 0.45  0.59 0.40 0.46  0.52 0.50 0.57  0.50 0.52 0.44  0.57 0.56 0.54  0.48 0.44 0.35  6.  Treatment 5 + 0.10% LIT i s o l e u c i n e  0.49 0.58 0.49  0.44 0.48 0.49  0.52 0.55 0.49  0.50 0.50 0.59  0.53 0.56 0.45  0.50 0.39 0.47  Table IB. A n a l y s i s o f variance o f the average d a i l y body'weight gain o f 107 p i g s . (Covariable s t a r t i n g weight).  Source  D.F.  Total  106  0. 859  Treatment (a)  5  Block (b) Sex  Variance Ratio F(nec.) p = 0.05 p = 0.01  M.S.  F-value  0. 374  0. 0748  19.939**  2.368  3.339  2  0. 0094  0. 0047  1.254  3.150  4.977  1  0.0257  0.0257  6.864*  4.001  7.077  a x b  10  0. 0231  0. 0023  0.616  1.993  2.632  axe  5  0. 0561  0. 0112  2.992*  2.368  3.339  b x c  2  0. 0102  0.0051  1.363  3.150  4.977  a x b x c  10  0. 0451  0.0045  1.202  1.993  2.632  Covariable  1  0.0333  0. 0333  8.871**  4.001  7.077  0.263  0. 0038  (c)  Residual *  P < 0.01  70  S.S.  **  P < 0.05  88  Table IIA. Average Feed intake (kg) per p i g p e r day f o r each r a t i o n . Treatment  . Rep 1  Rep 2  Rep 3  1.79  1.79  1.75  1.  Barley + Soybean  2.  Barley + L - l y s i n e HC1 (0.9% t o t a l l y s i n e )  1.64  1.61  1.55  3.  Barley + L - l y s i n e HC1 (0.75% t o t a l l y s i n e )  1.51  1.59  1.56  4.  Treat. 3 + 0.05% ^ t h r e o n i n e  1.74  1.67  1.81  5.  Treat. 4 + 0.10% DL-methionine  1.61  1.62  1.59  6.  Treat. 5 + 0.10% L - i s o l e u c i n e  1.66  1.67  1.63  Table I I B .  Source  Total  (Control)  A n a l y s i s variance o f average d a i l y feed intake.  D'.F.  S.S.  M.S.  17  1.3012  Treatment  5  1.1086  0.2217  Covariable starting weight  1  0.0253  0.0253  11  0.1017  0.00925  Residual ** *  P < 0.01 P < 0.05  F-value  23.9738** 2.7382  Variance Ratio F(nec.) P=0.05  P=0.01  3.2039  5.3160  4.8443  9.6460  89  Table I I I A .  Average feed conversion e f f i c i e n c y r a t i o p e r p i g . (D.M. feed intake (kg)/weight gain (kg).  Treatment  Rep 1  Rep 2  Rep 3  1.  Barley + Soybean (Control)  2.83  3.07  2.94  2.  Barley + 0.69% L - l y s i n e HC1 (0.9% t o t a l l y s i n e )  3.55  3.46  3.59  3.  Barley + 0.50% L - l y s i n e HC1 (0.75% t o t a l l y s i n e )  3.72  3.70  3.95  4.  Treat. 3 + 0.05% L-threonine  3.33  3.25  3.37  5.  Treat. 4 + 0.10% DL-methionine  3.40  3.20  3.30  6.  Treat. 5 + 0.10% L - i s o l e u c i n e  3.38  3.21  3.41  Table I I I B .  A n a l y s i s o f variance o f feed conversion e f f i c i e n c y r a t i o  Source  D.F.  S.S.  M.S.  F-value  12.72114**  17  0. 1328  Treatment  5  0. 1128  0. 0226  Covariable starting weight  1  0. 000157  0. 000157  0. 0195  0. 00177  Total  Residual *  P < 0.05 P < 0.01  11  0.0886  Variance Ratio F(nec.) p=0.05 p=0.01  3.2039  5.3160  4.8443  9.6460  90 Table IVA. Minimum middle f a t (mm) Rep 1 Rep 2 Male Female . Male Female  Treatment 1.  Barley + Soybean (Control)  2.  Barley + 0.69% L - l y s i n e ( t o t a l 0.90% l y s i n e )  32 30 29  3.  Barley + 0.50% L - l y s i n e ( t o t a l 0.75% l y s i n e )  4.  5.  6.  18  Rep 3 Male Female  20 25  24 23 19  29 24 18  20 18 21  20 20 23  32 28 22  32 33 27  21 24 19  21 28 17  24 18 21  25 24 22  10 23 18  29 24 26  28 17 22  16 25 30  14 15 19  Treatment 3 + 0.05% L-threonine  33 26 26  26 24 22  25 21 27  18 25 15  20 24 33  21 25 21  Treatment 4 + 0.10% DL-methionine  26 17 29  22 26  23 18 28  18 17 22  26 23 16  18 29 29  Treatment 5 + 0.10% L-isoleucine  32 25  24 25 28  27 28 30  25 18 20  24 25 26  19 18 22  — —  —  —  —  Table IVB. A n a l y s i s o f variance o f minimum middle f a t .  Source  D.F.  Total  102  S.S.  M.S.  F-value  Variance Ratio F(nec.) p = 0.05 p = 0.01  2344.427  Treatment (a)  5  197.5564  39. 5113  2.7410*  2.3683  3.3389  Rep  (b)  2  74.9634  37. 4817  2.6002  3.1504  4.9774  Sex  (c)  1  206.0355  206. 0355  4.0012  7.0771  10  270.2762  27. 0276  1.8750  1.9926  2.6318  axe  5  116.5186  23. 3037  1.6167  2.3683  3.3389  b x c  2  44.5127  22. 2564  1.5440  3.1804  4.9774  a x b x c  10  78.6352  7. 8635  0.5455  1.9926  2.6318  Covariable  1  162.9588  162. 9588  4.0012  7.0771  a x b  *  P < 0.05  ** P < 0.01  14.29337**  11.3050**  91 Table VA.  Eye muscle (width x depth) Rep 1 Male Female  Treatment 1.  Barley + Soybean (Control)  2 (mm ) o f the Rep 2 Male Female  103 pigs • Rep 3 Male Female  3666  3496 3876 —  3195 3744 3647  4080 3978 4131  3818 3456 4346  4131 3478 3773  —  2.  Barley + L - l y s i n e HC1 (0.9% t o t a l l y s i n e )  2451 2940 2280  3360 3408 3024  3216 2655 3168  3128 4080 3311  3818 3332 3848  3225 4480 3900  3.  Barley + L - l y s i n e HC1 (0.75% t o t a l l y s i n e )  3256 2747 2911  3724 3713 3621  3015 2418 3034  4272 3444 3698  3888 3240 3395  3654 3200 3096  4.  Treatment 3 + 0.05% L- threonine  3174 3036 3034  3330 4374 3519  2967 3358 3036  4437 3420 3588  3648 3626 4000  3036 3266 3430  5.  Treatment 4 + 0.10% DL-methionine  3600 2856 3696  3476 3360 —  3266 2829 3384  4080 3080 4042  3182 3036 3060  3266 3901 3219  Treatment 5 + 0.10% L-isoleucine  3010 3420  3042 3124 3285  3066 3330 3287  2970 3680 2775  2856 3195 3900  3358 3975 3640  6.  Table VB.  —  A n a l y s i s o f variance o f eye muscle (width x depth).  D.F.  S.S.  Total  102  21357320  Treatment (a)  5  1628173  325634.6  2.457*  2.368  3.339  Block  (b)  2  882920  441460.0  3.332*  3.150  4.977  Sex  (c)  1  2889814  288981.4  21.808**  4.001  7.077  a x b  10  2019311  201931.1  1.524  1.993  2.632  axe  „5  968194  193638.7  1.461  2.368  3.339  b x c  2  1949199  974599.5  7.355**  3.150  4.977  a x b x c  10  1050038  105003.8  0.792  1.993  2.632  Covariable  1  997188  997188.4  7.525**  4.001  7.077  66  8745643  132509.7  Residual * P < 0.05  M.S.  ** p < 0.01  F-value  Variance R a t i o F(nec.) p=0.05 p=0.01  Source  92  Table VIA. Nitrogen r e t e n t i o n (g/week).  Treatment  Rep 1  •1.  Barley + Soybean (Control)  2.  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  123.8  126. 5  115.1  116. 0  Barley + 0.69% L - l y s i n e HC1 (0.9% t o t a l l y s i n e )  56.0  59. 7  64.3  55. 3  42. 47  53.19  3.  Barley + 0.50% L - l y s i n e HC1  57.9  60. 5  72.4  67. 0  73. 01  80.61  4.  Treatment 3 + 0.05% L-threonine  74.2  70. 2  88.2  73. 0  53. 43  65.98  5.  Treatment 4 + 0.10% DL-methionine  56.2  63. 0  64.7  76. 4  56. 42  64.80  6.  Treatment 5 +.0.10% L-isoleucine  41.3  60. 6  86.6  79. 5  70. 79  84.22  Table VIB. A n a l y s i s o f variance f o r nitrogen r e t e n t i o n .  Source  Total Treatment Residual ** P < 0.01  D.F.  S.S.  33  14685.70  5  11565.06  28  3120.642  M.S.  F-value  2313.011  20.7535**  111.4515  Variance r a t i o F(nec.) P=0.05 P=0.01  2.5336  3.6990  93  Table VIC. A n a l y s i s o f co-variance f o r nitrogen r e t e n t i o n w i t h feed intake as the c o v a r i a b l e .  Source  Total  D.F.  S.S.  33  14697.28  M.S.  F-value  Variance ratio F(nec.) p=0.05 p=0.01  Treatment  5  9943.194  1988.639  63.4828**  2.5336  3.6990  Covariable starting weight  1  2275.892  2275.892  72.6526**  4.1709  7.5625  Residual  27  Table VID.  Source  Total  . S.S.  33  14685.70  5  Covariable starting weight  1  **  P = <0.01  27  31.3257  A n a l y s i s o f covvariance f o r n i t r o g e n r e t e n t i o n w i t h nitrogen intake as the covariable.  D.F.  Treatment  Residual  845.7928  945.2005 2153.281 967.3605  M.S.  F-value  Variance ratio F(nec.) p=0.05 p=0.01  189.0401  5.2763**  2.5336  2153.281 35.8282  60.1002**  3.6990  94  Table VIIA.  Nitrogen r e t a i n e d as a percentage o f nitrogen intake.  Treatment  Rep 1  Rep 2  Rep 3  Rep 4  ±.  earxey + ioyDean  45.54  42.77  45.43  46.64  2.  Barley + 0.69% L - l y s i n e (0.90% t o t a l l y s i n e )  38.07  35.94  38.57  3.  Barley + 0.50% L - l y s i n e (0.75% t o t a l l y s i n e )  38.03  35.15  4.  Treatment 3 + 0.05% L-threonine  49.95  5.  Treatment 4 + 0.10% DL-methionine  6.  Treatment 5 + 0.10% L-isoleucine  (Control)  Table VIIB.  Source  Total Treatment Residual ** P = < 0.01  Rep 5  Rep 6  30.64  37.09  39.37  41.57  35.78  38.89  40.14  45.35  45.73  37.41  36.12  38.90  45.27  43.50  45.81  46.15  42.00  41.74  37.99  45.81  48.26  40.95  41.11  46.86  A n a l y s i s o f variance f o r nitrogen r e t a i n e d as a percentage o f nitrogen intake.  D.F.  S.S.  M.S.  33  0.0668  5  0.0325  0.0065  28  0.0343  0.0012  F-value  Variance r a t i o F(nec.) p=0.05 p=0.01  5.3117**  2.5336  3.6990  95  Table VIIIA.  Apparent nitrogen d i g e s t i b i l i t y (%).  Treatment  Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  —  —  1.  Barley + Soybean (Control)  72.85  72.55  81.30  77.47  2.  Barley + 0.69% L - l y s i n e HC1 (0.90% t o t a l l y s i n e )  65.25  65.98  66.42  57.49  65.74  66.60  3.  Barley + 0.50% L - l y s i n e HC1 (0.75% t o t a l l y s i n e )  59.84  57.50  66.69  62.44  62.17  63.03  4.  Treatment 3 + 0.05% L- threonine  69.88  67.31  63.99  59.14  63.40  62.84  5.  Treatment 4 + 0.10% DL-methionine  66.35  68.82  68.72  65.37  63.52  63.26  6.  Treatment 5 + 0.10% L-isoleucine  65.24  68.70 . 71.27  65.23  63.86  69.08  Table VIIIB.  A n a l y s i s o f variance f o r apparent n i t r o g e n d i g e s t i b i l i t y .  M.S.  F-value  Variance ratio F(nec.) p=0.05 p=0.01  0.0537  0 .0107  9.957**  2.5336  0.0302  0 .0011  Source  D.F.  S.S.  Total  33  0.0840  5 28  Treatment Residual ** P < 0.01  3.6990  96  Table IXA. Nitrogen r e t a i n e d as a percentage o f nitrogen absorbed.  Treatment  Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  1.  Barley + Soybean (Control)  62.51  58.96  55.88  60.20  2.  Barley + 0.69% L - l y s i n e (0.90% t o t a l l y s i n e )  58.35  54.50  58.07  53.30  56.42  59.11  3.  Barley + 0.50% L - l y s i n e (0.75% t o t a l l y s i n e )  63.55  61.13  62.23  57.31  62.56  63.68  4.  Treatment 3 + 0.05% L-threonine  71.47  67.37  71.46  63.26  56.86  61.90  5.  Treatment 4 + 0.10% DL-methionine  68.23  63.21  66.66  70.59  66.13  65.97  6.  Treatment 5 + 0.10% L-isoleucine  58.22  66.67  67.71  62.83  64.38  67.84  —  —  Table IXB. A n a l y s i s o f variance f o r n i t r o g e n r e t a i n e d as a percentage o f nitrogen absorbed.  M.S.  F-value  Variance r a t i o F(nec.) p=0.05 p=0.01  0.0437  0.0087  7.153**  2.5336  0.0342  0.012  Source  D.F.  Total  33  0.0779  5 28  Treatment Residual ** P <0.01  S.S.  3.6990  

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