Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Skeletal development in the blacktail deer (Odocoileus hemionus columbianus) Addison, Ralor Blendle 1966

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1966_A6_7 A3.pdf [ 11.89MB ]
Metadata
JSON: 831-1.0093628.json
JSON-LD: 831-1.0093628-ld.json
RDF/XML (Pretty): 831-1.0093628-rdf.xml
RDF/JSON: 831-1.0093628-rdf.json
Turtle: 831-1.0093628-turtle.txt
N-Triples: 831-1.0093628-rdf-ntriples.txt
Original Record: 831-1.0093628-source.json
Full Text
831-1.0093628-fulltext.txt
Citation
831-1.0093628.ris

Full Text

SKELETAL DEVELOPMENT IN THE BLACKTAIL DEER (Odocoileus hemionus columbianus)  by RALOR BLENDLE ADDISON B.Sc,  University of B r i t i s h Columbia, 1963  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of Zoology  We accept this thesis as conforming to the required standard  THE UNIVERSITY OF BRITISH COLUMBIA May, 1966  In p r e s e n t i n g ' t h i s t h e s i s  in p a r t i a l  f u l f i l m e n t of  requirements f o r an advanced degree at the U n i v e r s i t y of Columbia, for  I agree t h a t the L i b r a r y  r e f e r e n c e and s t u d y .  I further  s h a l l make i t  freely  the  British available  agree that p e r m i s s i o n f o r  ex-  t e n s i v e c o p y i n g of 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 gran by the Head o f my Department o r by h i s  representatives.  understood t h a t c o p y i n g o r p u b l i c a t i o n of t h i s t h e s i s f o r cial  g a i n s h a l l not be a l l o w e d w i t h o u t my w r i t t e n  Department  of  The U n i v e r s i t y of B r i t i s h Columbia Vancouver 8, Canada Date  It  is  finan-  permission.  ii  ABSTRACT  Seventeen male deer fawns of the year  (Odocoileus hemionus colum-  bianus) were raised to ages of four or s i x months.  During this time, the  n u t r i t i o n of these animals was c o n t r o l l e d so that f i v e d i f f e r e n t patterns of alimentation were produced. The changes in the growth increments of the various regions of the skeleton with the pattern of alimentation were documented.  An analysis  of the changes led to an interpretation of the r e l a t i v e growth p r i o r i t y exhibited by each skeletal element up to four months, and from four to s i x months of age. The magnitude of the increment to each skeletal dimension was related to the total d i g e s t i b l e energy intake of the animal over the experimental period, and to the pattern of alimentation which led to t h i s energy intake.  The growth gradients described in the l i t e r a t u r e as a typical mam-  malian pattern were confirmed  for deer and were quantitated g r a p h i c a l l y .  The p r i n c i p l e s evolved from the experiment were applied to estimating the total energy intakes of two f i e l d animals at s i x months of  age.  The results of this study showed that this method of energy evaluation possesses a potential for direct f i e l d a p p l i c a t i o n .  i ii  TABLE OF CONTENTS Page ABSTRACT  ii  TABLE OF CONTENTS  ii i  LIST OF TABLES  v  LIST OF FIGURES  vi  ACKNOWLEDGMENTS  v i i  INTRODUCTION  1  EXPERIMENTAL  2  A.  Animals  2  Capture  2  Housing  2  Weight Measurement  3  Medication  3  B.  Planes o f N u t r i t i o n  k  C.  Rations  6  D.  Preparation o f Skeletons  13  RESULTS A.  R a t i o n Energy L e v e l s Digestibility  16 16  1.  Milk Substitute  16  2.  P e l l e t e d Rations  19  D i g e s t i b l e Energy B.  Cumulative  Energy I n t a k e  C.  Weight Gains on D i f f e r e n t Planes o f N u t r i t i o n  lg 23 2 7  iv  RESULTS, cont'd. D.  Page  Skeletal Measurements  27  Actual Dimensions Changes in Skeletal Dimensions with Energy at Six Months  27 Intake  Changes in Percent Growth Increment with Energy Intake at Six Months  32  32  Changes in Percent Growth Increment with Energy Intake at Four Months  k3  DISCUSSION  60  A.  67  E f f e c t of the Degree of Energy Restriction  B.  Fore-1imb  67  Hind-limb  68  Vertebral Column  69  1.  Atlas and Axis  2.  Other Vertebrae  Effect of the Pattern of Energy Restriction  70 71  Fore-1imb  72  Hind-limb  72  Vertebral Column  C.  69  Jk  1.  Atlas and Axis  74  2.  Other Vertebrae  7^  Analysis of Unknowns Evaluation of Two Unknowns  ~]k 75  SUMMARY  79  BIBLIOGRAPHY  80  APPENDIX  82  LIST OF TABLES Table  1  Page  The d i s t r i b u t i o n o f t h e e x p e r i m e n t a l a n i m a l s i n t o t h e n u t r i t i o n a l treatments  7  2  The c o m p o s i t i o n o f P e e b l e ' s V - l e r M i l k Rep l a c e r  8  3  The c o m p o s i t i o n o f t h e Weaner R a t i o n , U.B.C.  k  The c o m p o s i t i o n o f t h e A d u l t R a t i o n , U.B.C.  5  The n u t r i e n t c o m p o s i t i o n o f r a t i o n U.B.C.  36-S-63  36-57  The n u t r i e n t c o m p o s i t i o n o f r a t i o n U.B.C.  11  36-57  compared w i t h t h e N.R.C. requirement f o r growing sheep 7  10  36-S-63  compared w i t h t h e N.R.C. requirement f o r growing sheep  6  9  The d i g e s t i b i l i t y o f t h e m i l k r e p l a c e r , weaner  12  ration,  and a d u l t r a t i o n  17  8  The m o i s t u r e c o n t e n t o f t h e a i r d r y feeds  18  9  The d i g e s t i b l e energy c o n t e n t o f t h e m i l k r e p l a c e r , weaner r a t i o n , and a d u l t r a t i o n  10  The c u m u l a t i v e energy  i n t a k e f o r each deer a t f o u r 2k  and s i x months 11  The weekly energy  12  The s k e l e t a l measurements from deer fawns V 18 and  13 \k  20  i n t a k e r e l a t e d t o body weight  V 2 3 a t t e n pounds body w e i g h t The average d i s p l a c e m e n t s o f t h e growth increments of bones from H-L t r e a t e d fawns from t h e s t a n d a r d c u r v e s (at 3 3 0 , 0 0 0 C a l o r i e s ) The i n t e r c e p t s o f t h e growth increments o f F i e l d A and F i e l d B w i t h t h e s t a n d a r d c u r v e s  26  31  73 76  VI  LIST OF FIGURES Graph  1 2 3  4-13 14-21 22-29 30  Page  R e l a t i n g energy l e v e l s o f t h e two p e l l e t e d r a t i o n s t o that of m i l k  22  The r e l a t i o n s h i p between t o t a l energy i n t a k e and body weight a t f o u r months  28  The r e l a t i o n s h i p between t o t a l energy i n t a k e and body weight at s i x months  29  The r e l a t i o n s h i p between s k e l e t a l s i z e and t o t a l energy i n t a k e a t s i x months  33-42  The r e l a t i o n s h i p between % growth increment and t o t a l energy i n t a k e a t s i x months  44-51  The r e l a t i o n s h i p between % growth increment and t o t a l energy i n t a k e a t f o u r months  52-59  H y p o t h e t i c a l c u r v e s o f % growth increment v e r s u s t o t a l energy i n t a k e r e l a t e d t o t h e peak o f maximum growth p r i o r i t y  64  vi i  ACKNOWLEDGMENTS  I wish to thank Dr. I. McT. Cowan, Dean of the Faculty of Graduate Studies (formerly Head of the Department of Zoology), f o r his permission to undertake t h i s project and f o r the use of the required f a c i l i t i e s , and for  his interest and encouragement throughout this study. My sincere thanks are extended to Dr. H.C. Nordan, Associate  Professor of Zoology at the University of B r i t i s h Columbia, and t o Dr. A.J.  Wood, Dean of Arts and Science at the University of V i c t o r i a (former"  ly Professor of Animal Science at the University of B r i t i s h Columbia), f o r their guidance in planning and conducting this project. I wish to express a special appreciation f o r the many hours spent by my fellow students, especially Mr. D. Leckenby and Mr. P. Whitehead, in discussion and in aiding with the menial chores associated with caring for  the animals.  1.  INTRODUCTION This study was  undertaken to provide an index by which the n u t r i -  tional history of a deer could be determined from an examination of the form and development of the animal at the end of s i x months growth. in  This,  turn, would indicate the adequacy of the range during that period of  time.  The e f f e c t of plane of n u t r i t i o n on growth and form in domestic  species has been, and s t i l l 1932;  Palsson,  1955;  l i f e studies in New  i s , an active area of investigation (Hammond,  McMeekan, 19^0). Zealand should  Riney  (1955)  suggested that w i l d -  include an investigation of animal  indices to n u t r i t i o n a l adequacy of the environment.  "In animal husbandry research  i t has been well established  that d i f f e r e n t levels of n u t r i t i o n can be responsible f o r differences in physical c h a r a c t e r i s t i c s . It should,  there-  fore, be possible to get some measure of the quality of n u t r i t i o n provided  by a given environment by careful study  of c e r t a i n physical aspects of the animal population i n volved  in that environment."  Other workers from t h i s laboratory have investigated the e f f e c t of varying feed intake on growth rate in deer (Bandy, 1 9 5 5  1957;  Cowan and Wood,  1955).  and  1965;  O'Keefe,  These studies, however, have been concerned  with body weight or external measurements as parameters of growth. the purposes of t h i s study, skeletal growth was  considered  promising avenue of investigation. The skeleton was  For  to be a more  selected because i t  can be measured accurately, and because i t is not subject to retrogression  2  d u r i n g p e r i o d s o f d e p r i v a t i o n o f energy.  Further, i t s distribution  throughout t h e body e n a b l e s i t t o be a f f e c t e d by d i f f e r e n t i a l priorities.  The r e s u l t s o f K l e i n  growth  (1964) s u p p o r t t h e s e l e c t i o n o f t h e  s k e l e t o n f o r such a s t u d y .  EXPERIMENTAL A.  Animals Capture: Fawns were c a p t u r e d near Courtenay on Vancouver  I s l a n d a t ages  r a n g i n g from one t o f o u r t e e n d a y s , e s t i m a t e d by t h e degree o f hoof  growth.  C a p t u r e p r o c e d u r e s c o n s i s t e d o f f i n d i n g a doe w i t h fawn, e i t h e r by t r a v e l l i n g t h e l o g g i n g company roads by t r u c k , o r by w a l k i n g t h r o u g h t h e a d j o i n ing  lands.  would  The fawns were t h e n chased on f o o t .  U s u a l l y t h e s t a r t l e d fawn  l i e on t h e ground and o f f e r no r e s i s t a n c e t o c a p t u r e . A n i m a l s c a p t u r e d d u r i n g t h e e v e n i n g and f o l l o w i n g morning were  kept i n camp u n t i l m i d - a f t e r n o o n when they were c r a t e d i n v e n t i l a t e d c a r d board boxes, 24 x 24 x 14 i n c h e s , and t r u c k e d t o t h e a i r p o r t f o r shipment. They were then f l o w n on t h e one hour t r i p t o Vancouver where t h e y were met at t h e a i r p o r t by c a r and t r a n s p o r t e d t o t h e animal f a c i l i t i e s a t U.B.C. Here, they were t a t o o e d i n one e a r .  The t a i l s and  inner p o r t i o n s of the  h i n d l e g s were shaved, and then t h e fawns were l e f t f o r s e v e r a l hours f o r e f e e d i n g was  be-  attempted.  Housing: The fawns were housed i n two f o o t by f o u r f o o t plywood pens s e t on  3.  a concrete f l o o r .  These f a c i l i t i e s were contained in the w i l d l i f e unit  described by Wood et_ aj_.  (1961).  The room was open to outside a i r and  l i g h t , so that the deer were exposed to the p r e v a i l i n g c l i m a t i c conditions with the exception of rain and direct wind. washed and bedded with dry sawdust.  The pens were d a i l y  A sodium hypochlorite solution  used in cleaning the walls and f l o o r .  The f l y population was  was  suppressed  successfully by coating the upper portions of the pen walls with an insect i c i d e , Korlan 2 4 E (DOW Chemicals). When the fawns reached twenty pounds, larger pens were required. In 1 9 6 3 , the middle walls were removed from between each pair of two by four foot pens to make the four by four foot pens which housed the animals 1  on r e s t r i c t e d d i e t s .  Those animals on unrestricted diets were moved to  four by ten foot pens with d i r t f l o o r s .  In 1 9 6 4 , the large pens were equip-  ped with wooden s l a t t e d f l o o r s , and both f u l l y fed and r e s t r i c t e d animals were housed in them.  Weight Measurement; AH  deer were weighed to the nearest one-half pound on a platform  scale (Fairbanks Morse Model  5264)  —  d a i l y for most of the experimental  period, but becoming as infrequent as every t h i r d day toward the end of the s i x month period.  At f i r s t , the fawns were carried from the pen to  the scale, but were led when they grew older and became accustomed to f o l lowing.  The fawns soon learned to stand alone on the platform while the  weight was being read.  Medicat ion: During the course of the experiment, the deer suffered a variety  4  of ailments. tinal  The most common and most e a s i l y treated problem was an intes-  infection causing scouring. A s i n g l e , o r a l , 20 mg dose of c h l o r -  t e t r a c y c l i n e (Aureomycin, Cyan am id) was usually s u f f i c i e n t to bring the infection under c o n t r o l .  If necessary, a second dose was given the f o l -  lowing day. During the summer of 1963, the low plane of n u t r i t i o n was found to be below maintenance, fawns.  resulting in the deterioration of the health of the  Pneumonia developed in eight of these deer.  Two recovered when  treated by intermuscular injections with a mixture of Procaine P e n i c i l l i n G, P e n i c i l l i n G Potassium, and Streptomycin Sulphate (Pen-Strep, Squibb); three cc the f i r s t day, and two cc each day f o r the next three days.  These  survivors were discarded from the experiment since i t was impossible to judge the effect that the i l l n e s s would have on future development and growth. Internal parasites were not found at any time during the two years.  The only external parasites were some l i c e found in the inguinal  region of some of the 1964 fawns.  These were treated successfully with a  local application of a d i l u t e solution of lindane (Isotox, Ortho).  B.  Planes of Nutrition  The basic plan of the experiment was to compare skeletons of animals of known ages and n u t r i t i o n a l h i s t o r i e s after they had been reared to equal ages or to equal energy intakes on one of four patterns of food restriction.  The f i r s t pattern, non-restriction, allowed ad 1ibitum feed  intake over the e n t i r e s i x month period. ignated H.P., f o r high plane of n u t r i t i o n .  Animals on this regime are desThe second treatment, the Lj.P.,  5.  or low plane of n u t r i t i o n , was established t o allow o n e - f i f t h pound of gain per day.  Two intermediate treatments were included in 1964; a L.P.  to H.P. reversal commencing October 15, and a H.P. to L.P. reversal commencing the same date. respectively.  These treatments were designated  L-H and H-L,  It was calculated that i f the L-H group realimented  fully  after the r e s t r i c t i o n was removed, the total feed intake of each i n t e r mediate group should be the same at s i x months. In 1963, deer were raised on H.P. and L.P. treatments.  A H.P.  group of three males and three females and a L.P. group of two males and two females were reared to s i x months of age.  The f i r s t objective of  the 1963 work was t o establish a s a t i s f a c t o r y low plane of n u t r i t i o n , and to determine i t s relationship to ad libitum feeding.  An approximate  estimate of the energy requirement f o r maintenance was established on the basis of the basal metabolic rate equation (Brody, 1945); B.M.R. = 7 0 . 3 W  K g  °  , 7 3 2 f  Digestible Calories per day.  It was assumed that i f B.M.R. followed this equation,  and that i f the  metabolic rate at maintenance were a constant multiple of B.M.R. (Brody, 1945), then a low plane of n u t r i t i o n could be calculated by adding an energy increment equivalent to o n e - f i f t h pound of t i s s u e gain t o the c a l culated maintenance l e v e l s .  T r i a l feeding schedules were established  o f f e r i n g amounts of feed equivalent  in d i g e s t i b l e energy to multiples of  B.M.R. ranging from 2 to 3 . Subsequent adjustments led t o the e s t a b l i s h ment of a s a t i s f a c t o r y standard reared.  upon which the L.P. animals could be  Based on the energy levels calculated f o r the rations, mainten-  ance was found t o be achieved  by multiplying the B.M.R. by 2 . 3 5 ;  6.  M.M.R. - 2 . 3 5  (B.M.R)  = 165.2 w„ Kg  0 734  Digestible Calories per day.  The increment of energy to allow o n e - f i f t h of a pound of gain per day was i n s i g n i f i c a n t l y small compared to the total energy requirement so the low plane of n u t r i t i o n was established on the basis of the above equation, modified by a d a i l y correction to maintain a constant growth rate. The d i s t r i b u t i o n of animals into the four n u t r i t i o n a l treatments for 1 9 6 3 and 1 9 6 4 is l i s t e d in Table 1 . Animals which became i l l or died, and were therefore discarded, are not l i s t e d .  Although the female data  have not been used in the preparation of t h i s t h e s i s , the numbers and d i s t r i b u t i o n of the female fawns have been included in the table.  C.  Rations Three rations were fed to each deer during the experiment.  Upon  a r r i v a l at the laboratory, they were placed on a milk substitute, Peeble's V - l e r (Table 2 ) . pounds.  u n t i l they had reached body weights of ten to f i f t e e n  At t h i s weight, the fawns were weaned onto a protein  high energy cereal ration (U.B.C.  36-S-63,  Table  3).  supplemented,  In September, they  were fed a less expensive ration of lower energy content, as the rumen was then becoming capable of digesting coarser food-stuffs (U.B.C. 3 6 - 5 7 , Table 4 ) . The rations were formulated from standard feed m i l l  ingredients  for which the nutrient compositions are well documented (Morrison, 1959; Ewing, 19 ) . Both of the dry pelleted rations used met the N.R.C. r e quirements f o r growing sheep  (Tables 5 S- 6 ) .  Although the ingredients  Table 1 Distribution of experimental animals into n u t r i t i o n a l treatments  Sex  Date K i l l e d  U 7 U 8 U 33  M M M  December December December  H.P.  U 10 U 11 U 14  F F F  December December December  L.P.  U 15 U 30  M M  December December  L.P.  U 32 U 38  F F  December December  H.P.  V 24  M  December  H.P.  V 13  F  December  H.P.  V 11 V 21  M M  October October  H.P.  V 7 V 22  F F  October October  L.P.  V 10 V 12  M M  December December  L.P.  V 9 V 16 V 17  F F F  December December December  L.P.  V 19 V 20  M M  October October  L.P.  V 14 V 15  F F  October October  L-H  V 8 V 26  M M  December December  H-L  V 25 V 27 V 28  M M M  December December December  Year  Group  1963  H.P.  1964  Animal No.  Table 2 Composition of Peeble's V-ler milk replacer  Ingredients dried skim milk  iron sulphate  dried butter mi lk  a n t i b i o t i c supplement  dried whey-product  Oxytetracycline  Tenox preserved animal f a t  Terramyc in  lec i t h i n  Vitamin A palmitate  sodium benzoate  Vitamin D  magnesium carbonate  Vitamin Bj  dicalcium phosphate  Vitamin B  Guaranteed Minimum Analysis  2  0  Nutrient:Energy Ratio  crude fat  16.0%  3 6 mgm per C a l o r i e *  crude protein  24.0%  54 mgm per Calorie  Vitamin A  Vitamin D  9  1 5 0 0 U.S.P. units per pound  7.424 units per Calorie  3 0 0 0 U.S.P. units  1.48 units per C a l o r i e  per pound Vitamin Bj  11 mgm per pound  5.4/<gm per Calorie  Vitamin B„  11 mgm per pound  5.4/«jm per Calorie  Apparent d i g e s t i b l e energy  Table 3_  36-S-63  Composition of Weaner ration, U.B.C.  Ingredient  Amount  ground barley  2 0 0 pounds  oat groats  390  wheat bran  130  herring meal  200  soya meal  100  skim milk  200  dried grass  150  dicalcium phosphate iodized s a l t Brewer's yeast  10 VT'O  20  chromic oxide  1  Irradiated yeast  2  Vitamin A  2,000,000 2000  units pounds  Table k Composition of Adult ration, U.B.C. 36-57  Inqred ient  Amount  corn meal  600 pounds  ground wheat  250  bran  275  molasses  150  beet pulp  200  V i t a Gras  200  soya bean meal  175  herring meal  110  bone meal  20  iodized s a l t  20  2000 pounds  11  Table 5_ Nutrient composition of ration U.B.C. 36-S-63 compared with the N.R.C. requirements for growing sheep  Nutrient  Digestible protein  Units  2  mgm/Cal.^  N.R.C. . requirements  36.3  U.B.C. 36-S-63  46.2  Ca  mgm/Cal.  0.97  1.37  P  mgm/Cal.  0.87  1.92  Vitamin A  I.U./Cal.  1.84  +*  Vitamin D  I.U./Cal.  0.5  +^  '  1  Calculated from total d a i l y requirements f o r a 60 pound lamb.  2 Crude protein x 60%. ^  Calories of apparent d i g e s t i b l e energy. Total contributions from a l l ration ingredients not known, but a p a r t i a l total exceeds the N.R.C. requirements.  Table 6 N u t r i e n t c o m p o s i t i o n o f r a t i o n U.B.C. 36-57 compared w i t h t h e N.R.C. r e q u i r e m e n t s f o r growing sheep  Nutrient  Digestible protein  2  Units  mgm/Cal.3  N.R.C. requirements'  36.3  U.B.C. 36-57  32  Ca  mgm/Cal.  0.97  1.01  P  mgm/Cal.  0.87  1.63  Vitamin A  I.U./Cal.  1.84  +**  Vitamin D  I.U./Cal.  0.5  + ^  '  C a l c u l a t e d from t o t a l d a i l y r e q u i r e m e n t s f o r a 60 pound lamb.  o  Crude p r o t e i n x 60%. J  C a l o r i e s o f apparent d i g e s t i b l e energy. T o t a l c o n t r i b u t i o n s from a l l r a t i o n i n g r e d i e n t s not known, but a p a r t i a l t o t a l exceeds t h e N.R.C. r e quirement.  13.  used in formulating the milk substitute were known, the r e l a t i v e amount of each used was not.  However, the Guaranteed Minimum Analysis given by  the company, along with the l i s t of ingredients indicated that the mix formed an adequate r a t i o n .  Also, the consistently good growth rates of  the high plane deer t e s t i f i e d to i t s adequacy (French et. aj_., 1956). The d i g e s t i b i l i t y of each ration was calculated using the chromagen technique of Schurch, Crampton and Lloyd (1950). was  Chromic oxide  added to the dry milk replacer at 0.5% of a i r dry weight for f i v e  days p r i o r to fecal c o l l e c t i o n , and then for the duration of a f i v e day c o l l e c t i o n period.  The chromic oxide was added at 0.05% to the pelleted  feeds during t h e i r preparation, and was therefore fed constantly throughout the experiment.  This had the advantage that a fecal c o l l e c t i o n could  be made at any time without waiting f o r the chromagen to e q u i l i b r a t e with the gut l i n i n g , or for the unmarked feed to pass from the gut.  During  the period of the d i g e s t i b i l i t y t r i a l s , samples of feed were c o l l e c t e d at i n t e r v a l s .  These and the fecal samples were ground and then oxidized  in an oxygen bomb calorimeter.  From the gross energy f i g u r e s , and the  calculated d i g e s t i b i l i t i e s , d i g e s t i b l e energy f o r each ration was c a l culated.  D.  Preparation of the Skeletons  The following method of slaughter was used since an estimate of total blood volume of the deer was required as part of another study. The deer was immobilized  by an intramuscular  injection of succinylcholine  chloride (Anectine; Burroughs, Wellcome 6- Co.).  After the drug had taken  e f f e c t , the animal was suspended by the hind legs.  The c a r o t i d a r t e r i e s  14.  were then severed and the blood c o l l e c t e d in a preweighed bucket. deer lapsed into unconsciousness  The  in a very few seconds, but the heart con-  tinued to beat for several minutes.  Later dissection showed that most of  the blood had been pumped from the animal. The carcass was after each step. with a knife. 1.  eviscerated and skinned, with body weights taken  Following t h i s , a l l dissectable meat and f a t was removed  The f i n a l cleaning was carried out by one of three methods.  The roughly cleaned skeleton was  a i r dried in a c o o l , dry portion  of the barn so that mold formation would not occur. a colony of Oermestid  beetles.  It was  then placed in  Cleaning in this manner took about two  weeks, with a maximum of two skeletons being handled at one  time.  This method was of advantage when cleaning the skeletons of younger animals.  The skeletons of these animals were e a s i l y damaged by cooking,  but were l e f t unhurt by the beetles. numerous. fat  The skeleton when i t was  in the bone t i s s u e .  The disadvantages, however, were  removed from the colony s t i l l  had much  Upon storage, this f a t became rancid and the  bones became obnoxious to work with.  To avoid spreading the beetles,  which destroy everything from woodwork to books, the skeletons had to be washed in an i n s e c t i c i d e .  Physical removal of adults and larvae was  s u f f i c i e n t , because eggs deposited upon the skeleton would hatch The operation of the beetle colony also caused d i f f i c u l t i e s . warm, humid conditions in the chamber, mold developed kill  an unattended  colony in two to three days.  occasions during the time that the colony was  not  later.  Under the  rapidly, and would  This occurred on three  used.  When this happened,  the chamber had to be cleaned, decontaminated, and a new colony started. It then took s i x to eight weeks before the colony had a s u f f i c i e n t number  15.  of beetles to be e f f e c t i v e . 2.  The second method used was  the building.  to expose the skeletons on the roof of  At the end of s i x months, most meat and fat had been re-  moved by the action of insects and weather, but a l l of the bones had a coating of mold. them of the mold. bones, but i t was  It was  necessary to cook the bones in hot water to r i d  This method had the advantage of not damaging the not used extensively because of the s i x month waiting  per iod. 3.  The t h i r d , and most generally used, method was  to take the s k e l -  etons, either dry or fresh, and process them in a tank of water at approximately  190 to 200°F for 20 to 2h hours.  Ammonium hydroxide was  to the water at a'level of 250 cc per 20 gallons. bones were separated storage. days.  The cooked meat and  by hand, and the bones were washed and dried for  The advantage was  that a skeleton could be completed in two  The disadvantages were that the method was  that the skeletons could be damaged by  All  added  time consuming, and  overcooking.  three methods produced comparable results; i . e . , the skeletal  parts were not greatly damaged during preparation.  Exceptions were four  skeletons cleaned by b o i l i n g , when the water overheated and caused d i s integration of some skeletal parts.  In these animals, only bones which  retained a glossy surface at a l l points of measurement were used. of the younger animals, epiphyses f e l l o f f during preparation. ity of retaining these animals in the data was  In some  The  valid-  tested by measuring two  skeletons which had survived preparation without this occurrence, cooking them further u n t i l the epiphyses f e l l o f f .  and then  The epiphyses were  16.  then glued back on and the bones remeasured.  The results showed no d i f f e r -  ences between the pairs of measurements, so a l l loose epiphyses were glued on, and the bones were included in the data without further  identification.  RESULTS A.  Ration Energy Levels Digestibi1ity; The d i g e s t i b i l i t y of each ration was determined  from the concentra-  tion in the feces of an indigestible chromagen included in the r a t i o n . The determinations are shown in Table 7. was determined  at several intervals to allow f o r a c a l c u l a t i o n of the  d i g e s t i b i l i t y of the ration as fed. 1.  Moisture content of each ration  The results are shown in Table  8.  Milk Substitute  The d i g e s t i b i l i t y of the milk diet was determined four L.P. fawns.  Chromic oxide was  for a group of  added to the milk replacer at a level  of 0.5% of a i r dry weight, or 0.525% of oven dry weight, and was mixed very thoroughly by hand.  Feces were c o l l e c t e d f o r the second f i v e day  portion of the ten day period that the fawns received marked feed. feces which were c o l l e c t e d d i r e c t l y from the animals were used. sawdust was  included in the samples.  Only  Thus, no  Because of the small amount of feces  c o l l e c t e d from each animal, a l l samples were lumped together f o r analysis. Apparently the high level of chromic oxide was harmful, since these four animals, and only these four, developed a condition of bloody mucus in the feces.  This should not have affected the results markedly,  Table 7_ D i g e s t i b i l i t y of the milk replacer, weaner ration, and adult ration  Sample  a) Milk replacer Feed  Dilution  O.D.J  % Digestibi 1 i t y  2  ration 500 ml  0.61519 0.61717 0.60050 0.61594 0.61499 av.  Feces  1 gm  5000 ml  0.6127 6 !  0.76545 0.67063 0.75543 0.74504  av.  0.73414  91.7%  b) Weaner r a t i o n . U.B.C. 36-S-63 Feed  250 ml  0.129 0.129  0.128 0.130 av. Feces  U 7  U 10  U 14 U 33  250  0.129  ml  0.335 0.520  0.486 0.345  61 to 75%  cont inued  Table  Sample  Dilution  cont'd.  O.D.,  1 gm  % Digestibi1ity'  c) Adult r a t i o n . U.B.C. 36-57 1:  Run  Feed  500 ml  Feces  500 ml  0.0298 (average of 4 samples)  U 7 U 10 U 14  0.0602 0.0789 0.0510  U 8  0.0727  42 to 63%  Run 2: Feed  500 ml  Feces  500 ml  U U U U  7 10 14 8  0.0407 (average of 4 samples)  0.1179 0.0857 0.0828 0.0887  49 to 64%  Optical density 2  % d i g e s t i b i l i t y = 100 ( 1 -  P.P. feed x volume of d i l u t i o n O.D. feces x volume of d i l u t i o n  Table 8 M o i s t u r e content o f t h e a i r dry feeds  Ration  Milk replacer  Weaner r a t i o n  Adult  ration  Date  % Water  Aug. 11, 1964  5.02  Oct.  10, 1964  5.13  Aug. 11, 1964  10.88  Sept.  12.45  15, 1964  Oct. 10, 1964  13.24  Aug. 11, 1964  10.48  Oct.  10, 1964  11.22  Dec.  1964  13.00  19.  since the amount of blood and mucus was small. 2.  Pelleted Rations  The d i g e s t i b i l i t i e s of the two pelleted rations were determined for each of four H.P. fawns.  Chromic oxide was  added to these rations  when they were prepared by a commercial producer. chromic oxide level  Measurements of the  in each ration were found to be highly variable from  sample to sample, but duplicate determinations on the same sample i n d i cated that the method gave high p r e c i s i o n .  The optical density readings  indicated values for chromic oxide levels in the feed both above and below the supposed level contained in i t . In recovery estimates by Czarrock et a [ , ( I 9 6 0 , the values were always too low.  It was  concluded  that the feed marker was not homogeneously mixed, and that the determinations were not of s u f f i c i e n t accuracy to use in energy c a l c u l a t i o n s . Digestible Energy: The d i g e s t i b l e energy for each of the three rations was  calculated  from the d i g e s t i b i l i t i e s , and the feed and fecal gross energies determined in an oxygen bomb calorimeter. The results are shown in Table 9.  Since  the d i g e s t i b i l i t y data for the pelleted rations were unreliable, the d i g e s t i b l e energy values from feed tables were calculated f o r the rations. Digestible energy values were obtained for each ration ingredient from ruminant  feed charts (Ewing, 19  ).  The values were used with the  understanding that they could only approximate the d i g e s t i b l e energy of a mixed r a t i o n , especially when fed to an e n t i r e l y d i f f e r e n t ruminant the one f o r which the charts were designed. weaner ration was  assessed at 3.^75  from  The d i g e s t i b l e energy of the  Calories per gram (10% moisture), and  Table 9_ Digestible energy content of the milk replacer, weaner ration, and adult ration  Rat ion  Milk replacer  Gross Energy'  %  Feed  Feces  4785 4731  3734  5  Dig.  2  Dig.E  3  (dry)  Dig.E  4  (air dry)  91.7%  4448  4225  61-75%  26163274  2328-  42-63%  17152873  av. 4 7 5 8 Weaner rat ion  4448  U7 UIO U14  U33  4677 4526 4861 4721  2914  av. 4696 Adult rat ion  4393 4332  U7  4217  UIO  4310 3923  U14 .4363  U 3 3  4  0  9  1518-  2543  5  av. 4 1 3 6  Gross energy in Calories per kilogram. % digestibi1ity. Digestible energy in Calories per kilogram of oven dry feed. Digestible energy in Calories per kilogram of a i r dry feed (10% moisture). Group sample.  21  the adult ration at 3.136 Calories per gram (10% moisture). The values assumed f o r the pelleted rations were found to be reasonable when they were compared to the d i g e s t i b l e energy value that was determined experimentally for milk. only milk f o r the e n t i r e experimental  If the fawns could have been fed  period, a curve could have been  established r e l a t i n g the quantity of food required daily to maintain a growth rate of o n e - f i f t h of a pound per day. However, changing to a ration of a lower c a l o r i c density would require an increase in feed intake to achieve the same energy intake.  By measuring the increase in weight  of weaner ration over that of milk required to maintain the same growth rate, the energy content of the weaner ration r e l a t i v e to that of milk can be estimated. By extrapolating the feed intake versus body weight curve f o r L.P. animals receiving milk to higher body weights, and comparing i t to the feed intake versus body weight curve f o r weaner ration, the increase in feed intake could be determined.  For the two curves to be confluent  on an energy basis when the d i g e s t i b l e energy of milk was taken as 4.225 Calories per gram, the d i g e s t i b l e energy content of the weaner ration must have been near 3.5 Calories per gram (Graph l j .  S i m i l a r l y , the weaner  ration feed intake versus body weight curve was extrapolated to overlap the adult ration curve.  When the d i g e s t i b l e energy of the weaner ration  was placed at 3.475 Calories per gram, the two energy curves could be made confluent by assuming the d i g e s t i b l e energy of the adult ration to be near 3.1 Calories per gram.  It seemed j u s t i f i a b l e , then, to use the feed table  figures of 3.475 Calories per gram of weaner ration, and 3.136 Calories per gram of adult ration in calculations of the d i g e s t i b l e energy intake  Graph J_ Relating energy levels of the two pelleted rations to that of milk  23.  of each deer. Although the feed table values were based on moisture levels of 1 0 % which were 2 to 3 % lower than the levels found in this study, no adjustments were made.  Because the approximated values agreed we11 when  treated as above, i t was thought that accounting for the s l i g h t d i f f e r ences in moistures would not improve the estimation.  B.  Cumulative Energy Intake Digestible energy was summated for each fawn from the time that  the animal was ten pounds until i t was k i l l e d . digestible  Table 1 0 gives the total  energy ingested by each animal up u n t i l October 1 5 , and for  those not k i l l e d in October, up u n t i l the time of death in December. Table 1 1 l i s t s the equations f o r changes  in feed intake with body weight  over these same periods of time. It should be noted that although energy intakes f o r L.P. animals were in the v i c i n i t y of 3 0 % lower than ad 1ibitum energy intakes at the same body weights, the r e s t r i c t i o n in total energy intake over s i x months was between 5 0 and 6 0 % .  This was caused by the slower growth rate of the  L.P. fawns, and hence the longer periods of time spent at each lower level of feed intake. The H-L fawns consumed a total amount of energy in between that of the L.P. and that of the H.P.  animals.  However, the L-H fawns showed  l i t t l e difference in total energy consumption from the L.P. fawns.  Re-  alimentation after the r e s t r i c t i o n in diet was removed was probably i n hibited  by the onset of some degree of sexual a c t i v i t y .  Table 10.  Cumulative energy intake  AW, **  SumE.I.,  26  16  99,093  10  29  19  107,004  16  10  43.5  33.5  188,957  V 11  16  10  52  42  261,997  u 7  15  10  59  49  219,853  12  u 8  15  10  49  39  206,081  11  u 33  15  10  50  40  176,893  13  V 24  15  10  44  34  162,763  8  u 30  15  10  38.5  28.5  111,931  12  u 15  15  10  26  16  87,103  11  V 10  15  10  28.75  18.75  108,383  10  V 12  15  10  23.5  13.5  95,307  10  V 8  16  10  45  35  186,166  9  V 26  15  10  47  37  198,330  9  Animal  N,  V 20  16  10  V 19  15  V 21  1  W  2  Q  W,  3  5  N' 2  Number of days in period 1. Weight  in pounds at the start of period 1.  Weight  in pounds at the end of period 1.  Weight change in pounds during period 1. Cumulative energy intake during period 1 in Calories of apparent d i g e s t i b l e energy.  f o r each deer at f o u r and s i x months  Wo  A Wo  Sum E . I .  2  Sum E . l . j + Sum E . l .  89.5  30.5  347,829  567,682  76  37  289,350  495,431  83  33  358,569  535,462  64.5  20.5  181,944  343,707  59  20.5  186,243  298,174  41  15  138,088  225,191  109,860  218,243  14  117,854  213,161  52  7  134,559  320,725  54  7  138,282  336,612  9.25  38 37.5  ^  Number; o f days i n p e r i o d 2.  ^  Weight i n pounds at end o f p e r i o d 2.  10 2  o Weight change i n pounds d u r i n g p e r i o d 2. o C u m u l a t i v e energy i n t a k e d u r i n g p e r i o d 2 i n C a l o r i e s o f apparent d i g e s t i b l e energy. ^  C u m u l a t i v e energy i n t a k e d u r i n g p e r i o d 1 and p e r i o d 2 in C a l Q r i e s o f apparent ' d i g e s t i b l e energy.  26.  Table JJ. Weekly energy intake related to body weight  y =» ax  Animal  y = F. I. per week (Calories of apparent digestible energy) x = average body weight for that week (pounds) Period 1 a  b  Period 2 a  b  V 20  382.8  0.9745  V 19  573.2  0.8138  V 21  248.9  1.1825  V 11  327.8  1.1406  U7  266.8  1.1507  U 8  377.0  1.0805  U 33  377.8  1.0312  11270  V 24  168.4  1.2844  109000  -0.3904  U 30  576.6  0.8064  5299  0.2754  U  733.1  0.7144  5213  0.2452  1018.0  0.6415  4764  0.2371  12  527.0  0.8660  1263  0.6521  V 8  254.5  1.1662  24.68  1.6525  V 26  571.8  0.9329  15  V 10 V  155600 -0.3873 187.3  5.166  1.2212 0.2077  2.0515  27.  C.  Weight Gains on Different Planes of Nutrition There was a reasonable good c o r r e l a t i o n between body weight and  cumulative energy intake for unvaried planes of n u t r i t i o n (Graphs 2 & 3_). The H-L animals (Graph 3 ) . however, deviated to the right of this curve. This graph emphasizes the fact that weight alone is not an adequate measure of n u t r i t i o n a l plane.  D.  Skeletal Measurements Actual Dimensions: The bones which were selected to be measured were those expected  to encompass the growth gradients described by Huxley (1932), (1955).  and Palsson  Measurements were taken from: a)  four bones of the fore limb; fore-cannon, radius, humerus, and scapula  b)  four bones of the hind limb; hind-cannon, t i b i a , femur, and pelvis  c)  eleven vertebrae; a t l a s , axis, c e r v i c a l s 3 , 5 , and 7, thoracics 1, 10, and lumbars 1,  5 , and  3 , and 5 .  Each one of these groups should comprise a growth gradient; i . e . , growth p r i o r i t i e s proceed from d i s t a l to proximal regions, and from anterior and posterior to loin regions.  Depressed growth over the whole gradient would  indicate a low plane of n u t r i t i o n , and greater depression over r e s t r i c t e d areas of the gradients should indicate time s p e c i f i c energy r e s t r i c t i o n s . Between four and s i x measurements were taken from each bone  28.  Graph 2 The relationship between total energy intake and body weight at four months  29.  Graph 3_ The r e l a t i o n s h i p between t o t a l energy i n t a k e and body weight at s i x months  30.  examined, and in the case of the limb bones, the values f o r the l e f t and right sides were averaged.  From a l l the measurements, one or two were  selected from each bone as being the most useful. ed f o r various reasons:  some were d i f f i c u l t to reproduce accurately, and  others showed great individual v a r i a b i l i t y . the fore and hind limb bones was total measurements, total  The others were r e j e c t -  The measurement selected f o r  length.  For the vertebrae, two  length from the t i p s of the prezygopophyses to the  t i p s of the postzygopophyses, and the width across the transverse processes were used.  In the lumbar vertebrae, the width across the transverse  processes was highly variable, and the width across the prezygopophyses was substituted. Appendix 1 shows the anatomical d e t a i l s of the skeleton and the p i c t o r i a l descriptions of the measurements. It must be emphasized here, however, that although the same measurements were used f o r the d i f f e r e n t vertebrae, they cannot be considered a true s e r i e s .  Because of the various shapes and functions repre-  sented by the vertebrae, the growth vectors are l i k e l y to vary from region to region.  However, within an area of r e l a t i v e l y constant shape; e.g.,  the c e r v i c a l , thoracic, or lumbar regions, the measurements may represent a series. Two female fawns were k i l l e d at the arbitrary s t a r t i n g point of the experiment at ten pounds.  A l l bone measurements from other  animals  were expressed as a r a t i o to the average s i z e f o r that bone from the ten pound animals.  In other words, measurements are expressed as multiples  of the s i z e at ten pounds. shown in Table 12.  The measurements of the ten pound fawns are  T a b l e 12 S k e l e t a l measurements f r o m deer fawns V 18 and V 23 at t e n pounds body weight  Bone  Size V 18  V 23  f o r e cannon radius humerus scapul a  10.33 cm 9.76 9.56 7.63  10.55 cm 9.82 9.75 7.82  10.44 9.79 9.66 7.73  h i n d cannon tibia femur pelvis  12.5 14.1 11.11 10.29  12.7 14.2 11.29 10.19  12.6 14.15 11.20 11.20  2.40 3.28 2.18 2.07 1.90 1.89 1.61 1.58 1.98 2.14 2.06  2.30 3.15 2.13 2.07 1.90 1.81 1.58 1.63 1.91 2.10 2.04  2.35 3.22 2.16 2.07 1.90 1.85 1.60 1.61 1.95 2.12 2.05  Av,  F o r e 1imb: Length:  Hind l i m b : Length:  V e r t e b r a l column: Length:  Width:  atlas axis cervical cervical cervical thoracic thoracic thoracic lumbar 1 lumbar 3 lumbar 5 atlas axis cervical cervical cervical thoracic thoracic thoracic lumbar 1 lumbar 3 lumbar 5  3 5 7 1 5 10  3 5 7 1 5 10  2.22 2.16 2.58 3.06 2.90 2.49 2.23 1.52 1.74 2.13  _  2.29 2.09 2.37 2.96 2.77 2.44 2.09 1.45 1.65 2.01  _  2.26 2.13 2.48 3.01 2.84 2.47 2.16 1.49 1.70 2.07  32  Changes in Skeletal Dimensions with Energy Intake at Six Months: The s i z e r a t i o s , dimension at slaughter dimension at 10 pounds  w  e  r  e  c  o  m  p  a  r  e  d by i n d i v i d -  ual bone against total energy intake f o r the animals k i l l e d at the age of s i x months.  Graphs k_ to 13_ show t h i s relationship.  Animals on L-H and  H-L treatments were not used in p l o t t i n g these graphs, but the points were added later to show their positions r e l a t i v e to the l i n e s .  The L.P.  and H.P. data separated into two groups, one around 2 0 0 , 0 0 0 Calories total energy intake, and the other around 550,000 Calories.  One H.P. animal,  V 2k, consumed only 3^5,000 Calories, and one L.P. animal received 291,000 Calories over the s i x month period.  These two formed a medium plane of  n u t r i t i o n , and allowed a curve to be f i t t e d to the data.  The curves  through these points were f i t t e d by eye, and were checked against another treatment of the data to be discussed in the next section. Changes in Percent Growth Increment with Energy Intake at Six Months: Because bone growth rather than overall s i z e was being considered, i t was thought p r o f i t a b l e to examine the differences in growth increments at d i f f e r e n t energy  intakes:  growth increment »  dimension at slaughter dimension at 10 pounds  _  ,  #  In order to compare a l l measurements on an equal basis, each was converted to a percentage as follows.  The l i n e of best f i t through the points of  U 7, U 8, and U 33 on each of Graphs h to J_3_ was judged by eye, and the intercept at 550,000 Calories was recorded.  This value f o r overall s i z e  was converted to a growth increment by the above formula, and the increment  Graphs h The  JJ_  relationship between skeletal s i z e and at s i x months  total energy intake  43.  was assumed to be the maximum increment possible in s i x months.  The  growth increments f o r each bone from a l l of the animals were then converted to percentages of the growth increment at the respective 550,000 Calorie intercept.  The percent growth increments were graphed against  total energy consumption, and a l i n e was f i t t e d to the data by eye (Graphs 14 to 2J_).  The l i n e of best f i t was then converted back to  total length measurements and was used to check the f i t of the lines to Graphs 4 to J J .  H-L and L-H points were again added later to show their  positions r e l a t i v e to the standard l i n e s .  Changes in Percent Growth Increment with Energy Intake at Four Months; Measurements from animals slaughtered at four months were treated in the same way as the s i x month data, with the exception that maximum growth  (growth increment = 100%) was assumed to be that of V 11,  261,997 Calories total energy intake.  at  Only four animals were in this age  group, and only three of these were used in f i t t i n g the curves.  Two  L.P.  fawns, V 19 and V 20, consumed approximately 100,000 Calories each, but had considerably d i f f e r e n t skeletal dimensions.  Since V 19 suffered a  rather severe setback when he broke his lower jaw at about three months of age and was unable to eat the f u l l amount of ration offered, i t was assumed that the discrepancies between the two animals were caused by this period of extreme r e s t r i c t i o n .  Because of t h i s , only measurements from  V 20 were used at the lower end of the curve.  The changes  in growth  ments with cumulative energy intake are shown in Graphs 22 to 22.  incre-  Graphs Uf - 2J_  The relationship between % growth increment and total energy intake at s i x months  Graphs 22 - 29_ The relationship between % growth increment and total energy intake at four months  60.  DISCUSSION The purpose of this study was to explore the nature and consequences of the competition for growth materials, using deer that suffered overall r e s t r i c t i o n s of diet and periodic r e s t r i c t i o n s in comparison with f u l l y alimented controls.  In as much as the study was conducted well  within the growing period of even the early p r i o r i t y skeletal elements, f i n a l s i z e and f i n a l consequences of the r e s t r i c t i o n were not available. Since growth can take place only upon the surplus of energy resources beyond the needs for maintenance and minimal essential the  activity,  time over which the energy is received is an essential element in the  growth s i t u a t i o n .  Two animals that have received the same energy total  over very d i f f e r e n t periods of time w i l l have had quite d i f f e r e n t portions of the energy budget to a l l o t to growth and w i l l have responded to the  growth demands of the various skeletal elements in d i f f e r e n t ways. It is well known that mammals exhibit a gradient of biological  a c t i v i t y in their development which results in r e l a t i v e differences in the  rates of growth of various regions of the body at any one time (Ham-  mond,  1932).  In early l i f e , the head and lower limbs develop most rapid-  ly, whereas at a much later date, the lumbar region exhibits the most rapid r e l a t i v e growth.  Within each of these regions, the tissues exhibit  a gradient in t h e i r p r i o r i t i e s for energy, with the nervous and skeletal systems exhibiting the highest p r i o r i t i e s in early l i f e .  I f , rather than  following the total growth, gradient through the body, one selects an i n dividual t i s s u e , a s i m i l a r time s p e c i f i c wave of growth intensity should be found.  In this study, the skeleton was the tissue selected.  61.  The use o f t i m e i n t h e d e s c r i p t i o n o f growth g r a d i e n t s i n v o l v e s a c o n s i d e r a t i o n o f both c h r o n o l o g i c a l and p h y s i o l o g i c a l t i m e .  I t was  shown by McCay e t al.. (1935 and 1939) t h a t r e s t r i c t e d f e e d i n g d e c r e a s e d the r a t e o f p h y s i o l o g i c a l aging i n r a t s .  That  i s , at any c h r o n o l o g i c a l  age, a r e s t r i c t e d animal would be p h y s i o l o g i c a l l y younger than an unrestricted control.  A s t u d y by L e w a l l and Cowan (1962),  investigating  t h e o r d e r o f e p i p h y s e a l c l o s u r e i n t h e l o n g bones o f B l a c k - t a i l  deer,  showed a d e l a y o f n e a r l y one y e a r i n t h e e p i p h y s e a l c l o s u r e s i n energy r e s t r i c t e d animals.  W i t h t h i s p r o l o n g a t i o n o f growing t i m e , i t might be  p o s s i b l e f o r t h e s k e l e t o n , a f t e r b e i n g i n t e r r u p t e d i n growth by a p e r i o d of  energy d e p r i v a t i o n , t o r e a c h t h e f u l l  animals f o r each s k e l e t a l element. documented.  s i z e a t t a i n e d by u n r e s t r i c t e d  That t h i s  i s not t h e c a s e i s w e l l  P h y s i o l o g i c a l age must bear a r e l a t i o n s h i p t o c h r o n o l o g i c a l  age, s i n c e d u r i n g r e s t r i c t e d growth, t h e p r i o r i t i e s f o r c e r t a i n or  tissues  r e g i o n s can be s u r p a s s e d ( P a l s s o n , 1955; Osbourn and W i l s o n , I 9 6 0 ) .  Growth appears, t o be m a i n t a i n e d i n p r o p o r t i o n t o t h e r e l a t i v e p r i o r i t i e s for  growth e x i s t i n g a t t h e t i m e o f r e s t r i c t i o n .  That  i s , a region of  h i g h p r i o r i t y w i l l c o n t i n u e t o grow at a r a t e c l o s e r t o t h e maximum at t h e t i m e than w i l l  a lower p r i o r i t y r e g i o n .  The r e c o v e r y a f t e r r e a l i m e n -  t a t i o n l i s most c o m p l e t e , however, i n r e g i o n s which have not y e t reached t h e t i m e o f maximum growth r a t e a t t h e t i m e o f r e s t r i c t i o n .  A restric-  t i o n a t t h e t i m e when t h e r e g i o n o f t h e s k e l e t o n i s c a p a b l e o f t h e g r e a t est  growth r a t e a l l o w s t h i s peak t o be passed w i t h o u t f u l f i l l m e n t .  Recovery  i s then l i m i t e d t o a p e r i o d d u r i n g which t h e r e i s a lower capac-  i t y f o r growth. A c o n s i d e r a t i o n o f t h e growth o f t h e i n d i v i d u a l bones o f t h e  62.  s k e l e t o n may h e l p t o c l a r i f y some p o i n t s .  The g e n e t i c maximum growth  p o t e n t i a l e s t a b l i s h e d at c o n c e p t i o n i s h e r e r e f e r r e d t o as t h e growth potential.  In an animal growing in a p a t t e r n f u l f i l l i n g t h e g e n e t i c  p o t e n t i a l s f o r a l l components, any bone would r e a c h a maximum s i z e at a maximum growth r a t e .  S i n c e t h i s s t u d y was conducted w e l l w i t h i n t h e grow-  ing p e r i o d o f t h e a n i m a l s , a c o n s i d e r a t i o n o f maximum s i z e i s o f importance.  Growth r a t e i s i m p o r t a n t , because growth r a t e governs  growth increment and hence t h e overa11 s i z e o f t h e bone.  little the  Even under  the  best c o n d i t i o n s p r o v i d e d f o r t h e H . P . deer i n t h i s s t u d y , t h e r e were i n d i c a t i o n s t h a t showed t h a t t h e g e n e t i c p o t e n t i a l s t o grow had not been reached.  As a r e f e r e n c e p o i n t , t h e o v e r a l l s i z e of t h e bone from a H . P .  fawn at any t i m e , i n t h i s c a s e f o u r and s i x months, was c a l l e d t h e maximum growth c a p a c i t y t o t h a t p a r t i c u l a r t i m e .  T h i s i s o f g r e a t e r use than  growth p o t e n t i a l because t h e maximum growth c a p a c i t y was a c h i e v e d under t h e c o n d i t i o n s of t h e e x p e r i m e n t .  Growth r a t e i s another d i f f i c u l t term  w i t h w h i c h t o d e a l because i n o r d e r t o compare t h e growth r a t e s o f ent bones o f d i f f e r e n t  differ-  s i z e s , t h e growing masses s h o u l d be c o n s i d e r e d .  Comparison was a c c o m p l i s h e d by e x p r e s s i n g t h e s k e l e t a l measurements as a m u l t i p l e o f t h e s i z e o f each bone at b i r t h , e s t a b l i s h i n g s i z e r a t i o s .  By  s u b t r a c t i n g ' 1 ' from t h e s i z e r a t i o , t h e growth increment i n terms o f m u l t i p l e s o f b i r t h dimension c o u l d be c a l c u l a t e d .  S i n c e t h e maximum growth  c a p a c i t y was d e s c r i b e d as t h e o v e r a l l s i z e of t h e bone o f a H . P . fawn at a p a r t i c u l a r t i m e , t h e growth increment o f t h e s e a n i m a l s was c a l l e d t h e maximum growth i n c r e m e n t .  By p l a c i n g t h e maximum growth increment n u m e r i -  c a l l y equal t o 100%, t h e growth increments at o t h e r l e v e l s o f energy c o u l d be r e l a t e d t o t h i s as a p e r c e n t growth i n c r e m e n t .  It  intake  is t h i s f i n a l  63  t e r m , t h e p e r c e n t growth increment  (% G . I . )  t h a t has been used e x c l u s i v e l y  in the a n a l y s i s of the d a t a . By g r a p h i n g t h e % G . I . t h e c u m u l a t i v e t o t a l energy  f o r a g i v e n bone at a s p e c i f i e d age a g a i n s t  i n t a k e over a wide range of p l a n e s o f  t i o n , a c u r v e can be e s t a b l i s h e d .  The p l a n e s of n u t r i t i o n r e f e r r e d  here a r e t h e c o n s t a n t r a t e s of n u t r i t i o n d u r i n g t h e e n t i r e period;  i . e . , H.P., M.P.,  and L . P .  c u r v e must i n t e r s e c t 100% G . I .  nutri-  experimental  By t h e d e f i n i t i o n o f % G . I . ,  at t h e average H . P , t o t a l energy  The b e h a v i o r o f t h e c u r v e at lower energy  to  each intake.  intakes is a f u n c t i o n of  the  p r i o r i t y f o r growth e x h i b i t e d by t h e bone d u r i n g t h e t i m e i n t e r v a l  being  considered.  The p r i o r i t y f o r growth i s e s t a b l i s h e d as a r e s u l t of  the  s t r e n g t h o f t h e energy demands of one element r e l a t i v e t o t h o s e o f  all  others.  Some o f t h e h y p o t h e t i c a l c u r v e s which c o u l d r e s u l t a r e shown  Graph 30 and w i l l  in  be d i s c u s s e d h e r e .  Each of t h e c u r v e s shown in Graph 30 d e s c r i b e s a s i t u a t i o n which c o u l d r e s u l t when t h e % G . I . s a g a i n s t c u m u l a t i v e energy  o f a g i v e n bone dimension a r e p l o t t e d  i n t a k e f o r animals which have been r e s t r i c t e d  at a c o n s t a n t r a t e f o r t h e d u r a t i o n of t h e t i m e p e r i o d . periodic restriction w i l l  The e f f e c t s o f  be d i s c u s s e d l a t e r w i t h s p e c i f i c r e f e r e n c e t o  the data. S e r i e s ' A ' shows t h e p r o g r e s s i o n of c u r v e shapes r e s u l t i n g from r e s t r i c t i n g energy  i n t a k e b e f o r e t h e t i m e of h i g h e s t p r i o r i t y f o r  through t o t h e r e s t r i c t i o n of energy d u r i n g t h e p e r i o d o f h i g h e s t  growth priority.  S e r i e s ' B ' sshows t h e p r o g r e s s i o n of c u r v e shapes r e s u l t i n g from r e s t r i c t ing energy  i n t a k e d u r i n g o r a f t e r t h e p e r i o d of h i g h e s t p r i o r i t y .  'A-l'  r e p r e s e n t s t h e b e h a v i o r o f a bone which has not y e t begun t o grow at a  64.  Graph 3.0 Hypothetical curves of % growth increment versus total energy intake related to the peak of maximum growth p r i o r i t y  65.  rapid rate. of n u t r i t i o n .  The r e q u i r e m e n t s a r e s m a l l and can be met by a medium p l a n e Further r e s t r i c t i o n s  i n energy c a u s e a r a p i d d e c l i n e i n  % G.I. because t h i s bone c a n not compete f o r n u t r i e n t s a g a i n s t o t h e r s g r e a t e r demands. high.  In ' A - 4 ' , t h e growth p r i o r i t y and t h e energy demands a r e  A r e s t r i c t i o n i n t h e p l a n e o f n u t r i t i o n r e q u i r e s t h a t t h e bone must  compete f o r energy. % G.I.  The r e s u l t i n g  c o m p e t i t i o n causes a somewhat d e c r e a s e d  The s t r e n g t h o f t h e growth p r i o r i t y i s emphasized by t h e b e h a v i o r  o f t h e c u r v e at very  low energy l e v e l s .  T h i s bone i s a b l e t o m a i n t a i n i t s  growth r a t e much b e t t e r than t h e bone r e p r e s e n t e d 'A-3'  with  i n d i c a t e intermediate p r i o r i t i e s .  *B-1  1  by ' A - l ' .  i s s i m i l a r t o 'A-4  'B-4' represents  t h e bone has a h i g h growth r e q u i r e m e n t .  ' A - 2 ' and i n that  1  a situation in  w h i c h t h e bone i n animals w i t h r e l a t i v e l y h i g h energy i n t a k e s has  achieved  t h e major p a r t o f i t s growth, and f u r t h e r energy i n t a k e at a l a t e r d a t e 'B-2  does l i t t l e t o i n c r e a s e t h e d i m e n s i o n o f t h a t p a r t o f t h e s k e l e t o n . and  'B-3  1  are again  1  intermediate p o s s i b i l i t i e s .  It s h o u l d be noted t h a t an a n a l y s i s o f t h e growth p r i o r i t y f o r a g i v e n bone c o u l d r e s u l t  i n t h e p r o d u c t i o n o f any one o f t h e s e  depending on t h e t i m e at w h i c h t h e samples were t a k e n . p o i n t s were used i n t h i s experiment curves  curves,  Only two r e f e r e n c e  f o u r months and s i x months.  f o r each bone at f o u r months a r e t h e r e f o r e an a c c u m u l a t i o n  growth p r o c e s s e s  up t o f o u r months o f age, and t h e c u r v e s  d e s c r i b e t h e sum o f t h e growth p r o c e s s e s  The  of the  at s i x months  t o s i x months o f age.  The o c c u r -  rences between f o u r and s i x months can be i n t e r p r e t e d by e x a m i n i n g both t h e f o u r and s i x months c u r v e s .  In l o o k i n g a t t h e d a t a ,  i t is difficult  t o assess t h e s t a t u s o f t h e bone as t o i t s r e l a t i v e p o s i t i o n t o t h e t i m e o f peak growth r a t e .  A c u r v e w i t h t h e shape o f ' A - l ' c o u l d a l s o d e s c r i b e  66.  a series of events leading to the production of a ' B-4' However, an 'A-l* or B-V 1  type of pattern.  curve at four months followed by a curve at  s i x months with the shape of B—1 1  1  would d e f i n i t e l y place the growth  p r i o r i t y of this bone as pre-maximum at four months, and near maximum between four and s i x months.  ' A - l ' followed by 'B-4* could be interpreted  as being s t i l l pre-maximum at s i x months, or being post-maximum at a very early age. This can be i n t u i t i v e l y resolved by examining the position and function of the bone in the body.  For example, to f i n d this behavior in  a limb or skull element would most d e f i n i t e l y mean that the maximum growth p r i o r i t y was at a very early age. Such a pattern in a l a t e maturing region would mean that the point of maximum p r i o r i t y f o r growth had not yet been reached. It should be apparent that these curves are classed as pre-maximum, maximum, or post-maximum in growth p r i o r i t y with reference to the H.P. fawns.  Since physiological aging  is delayed by r e s t r i c t e d feeding, the  severely r e s t r i c t e d animals in a curve of the type 'B-V would not necess a r i l y have passed the period of highest p r i o r i t y f o r growth.  This becomes  extremely important in the evaluation of the potential a b i l i t y to compensate after realimentation. The following discussion is divided into three sections:  the  effect of the degree of energy r e s t r i c t i o n over the total time period; the effect of a short term energy r e s t r i c t i o n ; and the application of the p r i n c i p l e s here derived to the analysis of the energy intake of unknown animals. The four month % G.I. curves were constructed using 262,000 Calories as the energy level producing  a 100% G.I.  However, the H.P. animals which  67  were raised to s i x months only averaged a t o t a l energy intake of 200,000 Calories at four months.  In discussing the r e l a t i v e growth rates of  low  plane and high plane deer in the next sections, the 200,000 C a l o r i e i n t e r cepts from the graphs at four months w i l l be used as the H.P.  A.  standards.  Effect of the Degree of Energy Restriction  In t h i s experiment, r e s t r i c t e d feeding limited the s i z e of the skeletons of the nineteen deer studied.  Each measurement was  found to  vary in some manner with feed intake, but the extent of the e f f e c t not  identical from bone to bone, nor was  sions of the same bone. i c a l l y the form of any  was  i t the same f o r d i f f e r e n t dimen-  No attempt has been made to describe mathematl i n e r e l a t i n g skeletal dimension to energy intake,  but patterns appear in the curves and can be interpreted to some extent. In the following section, growth gradients in the fore-limb,  hind-limb,  and vertebral column w i l l be examined in turn.  Fore-1imb; At four months, the fore-limb measurements indicated that the highest growth p r i o r i t i e s had occurred  in the more d i s t a l  types previously described as 'A-2 , ^-3', 1  and  'A-4'  graded series from the scapula to the fore-cannon. only s l i g h t l y below H.P.  regions.  Curve  were found in a  An energy decrement  caused a considerably greater decrease in the  growth of the fore-cannon than i t did of the scapula. low energy l e v e l s , growth was maintained cannon than in more proximal  bones.  However, at very  at a greater rate in the f o r e -  On the L.P. treatment, the growth at  four months for the fore-cannon, radius, humerus, and scapula were 69,  68.  67, 62, and 56% of the respective H.P. four month growth capacities f o r these bones (taking 96,000 Calories as the average L.P. total energy i n take at four months, and 200,000 Calories as that for H.P. at four months). The only interpretation of this pattern of growth curves is that the d i s t a l elements were exhibiting stronger growth p r i o r i t i e s than the proximal parts.  The reason that the scapula was less affected by a mild  r e s t r i c t i o n was not that the bone had a high p r i o r i t y for growth, but rather that i t had such a low p r i o r i t y that i t s f u l l be^met by a medium plane of n u t r i t i o n .  requirements could  This is borne out by the fact that  the maximum growth capacity for the scapula at four months was only 65% of the maximum growth capacity at s i x months (taking 200,000 Calories and 550,000 Calories as the respective H.P. total energy intakes), whereas the fore-cannon, radius, and humerus had achieved over 73% of t h e i r s i x month maximum growth capacity. At s i x months, the pattern of the growth curves for the bones of the fore-1imb was e n t i r e l y d i f f e r e n t . Near maximum growth increments were achieved  at lower total energy levels in the more d i s t a l bones.  At energy  intakes above t h i s , l i t t l e or no further growth could be attained. humerus and scapula probably had entered priorities  The  their periods of maximum growth  in the H.P. animals, as evidenced by the steepness of the slope  of the curve at high levels of feed intake.  Since the humerus and scapula  exhibited low p r i o r i t y responses at four months, the growth p r i o r i t y for these bones could be fixed at later than four months, and l i k e l y extending beyond s i x months. Hind-1imb; The hind-limb exhibited exactly the same pattern of growth as the  69.  fore-limb, except that the series was  less pronounced.  The cannon was  d e f i n i t e l y e a r l i e r maturing than the other members of the limb, but the % G.I. curves of the t i b i a , femur, and pelvis were very s i m i l a r to each other.  At four months, the bones of the hind-limb of the H.P.  fawns had  achieved proportionately less of the s i x month maximum growth capacity than the fore-limb bones, with averages of 68 and 71% respectively for the s e r i e s .  This accounts f o r the hind-limb bones having curve types  which indicated a higher p r i o r i t y between four and s i x months than in the fore-1imb.  Vertebral Column; 1*  Atlas and Axis  These two bones appeared to grow in length in a pattern quite d i f f e r e n t from the other c e r v i c a l vertebrae.  Because of the specialized  functions of the atlas and axis, the length measurements cannot be considered to be part of the same series as the length measurements of the other c e r v i c a l s .  At four months, both bones showed strong tendencies to  grow in length, with that of the atlas being even stronger than that of the axis.  However, at this time, the atlas of a H.P.  animal had achieved  only 54% of i t s s i x month growth in length, while the axis had reached  73%.  On the L.P. treatment, the growth was 40 and 42% respectively of the maximum growth capacity at s i x months.  At s i x months, both bones s t i l l  appeared to be growing strongly, with no evidence of a maximum having been surpassed. The width measurements of the atlas were discarded because a consistent measurement could not be attained.  The width of the axis appeared  70  t o be much l a t e r m a t u r i n g than t h e l e n g t h . a x i a l w i d t h had o n l y a c h i e v e d 59% of l e n g t h had a c h i e v e d 73%. two months 2.  At f o u r months, t h e H . P .  i t s s i x month g r o w t h , whereas t h e  The growth c u r v e o f t h e w i d t h d u r i n g t h e f i n a l  i n d i c a t e d t h a t t h e w i d t h was then a h i g h p r i o r i t y  dimension.  Other V e r t e b r a e  The l e n g t h s of t h e o t h e r v e r t e b r a e showed v a r i a b l e growth t e n d e n c i e s from r e g i o n t o r e g i o n .  A l t h o u g h a l l v e r t e b r a e o f H . P . a n i m a l s had  a c h i e v e d 70 t o 80% o f s i x months growth i n l e n g t h , t h e shapes o f t h e z e r o t o f o u r month % G . I . r a t h e r low p r i o r i t y .  c u r v e s i n d i c a t e d t h a t growth was p r o c e e d i n g w i t h a The r e g i o n of  t h e v i c i n i t y of c e r v i c a l  lowest p r i o r i t y at t h i s t i m e was in  7 and t h o r a c i c 1,  growth i s not v e r y m e a n i n g f u l  The p e r c e n t a g e o f s i x month  f o r comparison i n t h e v e r t e b r a e because at  s i x months, growth i s f a r from c o m p l e t e , and t h e e x t e n t of c o m p l e t i o n v a r i e s from bone t o bone.  From f o u r t o s i x months, t h e L . P .  treatment  h e a v i l y r e s t r i c t e d t h e l e n g t h growth o f t h e t h o r a c i c v e r t e b r a e , and a l s o caused an i n c r e a s i n g r e s t r i c t i o n p o s t e r i o r l y i n t h e lumbar v e r t e b r a e .  It  i s e v i d e n t t h a t e i t h e r t h e l e n g t h s of t h e v e r t e b r a e do not e x h i b i t s t r o n g growth p r i o r i t i e s , o r t h a t they f a l l of  at some t i m e l a t e r than s i x months  age. The w i d t h s of t h e c e r v i c a l v e r t e b r a e showed low p r i o r i t i e s f o r  growth up t o f o u r months, and from f o u r t o s i x months showed moderate priorities.  The t h o r a c i c r e g i o n showed a s l i g h t l y h i g h e r p r i o r i t y  z e r o t o f o u r months, but l e s s from f o u r t o s i x months.  The lumbar  from region  appeared t o become an a r e a o f e x t r e m e l y h i g h p r i o r i t y from f o u r t o s i x months, w i t h a s l i g h t d e c r e a s e i n p r i o r i t y from lumbar 1 t o 5. e x c e p t i o n o f t h e w i d t h o f t h e lumbar v e r t e b r a e , t h e p r i o r i t y f o r  With t h e growth  71  in w i d t h does not seem t o equal t h a t f o r growth i n l e n g t h d u r i n g t h e six  months o f  B.  E f f e c t o f t h e P a t t e r n o f Energy R e s t r i c t i o n  first  life.  In a d d i t i o n t o t h e animals two o t h e r g r o u p s , t h e L-H  r e a r e d on u n v a r i e d p l a n e s o f n u t r i t i o n ,  and t h e H-L,  were r a i s e d t o s i x months o f  age.  The changes i n t h e p l a n e s o f n u t r i t i o n o c c u r r e d at f o u r months, at t h e t i m e t h a t t h e f o u r month samples were o b t a i n e d f o r t h e H.P.  and  L.P.  treatments. The t h a t was did  L-H  group o f t h r e e males d i d not r e a l i m e n t a t e t o t h e e x t e n t  e x p e c t e d , p r o b a b l y due t o t h e onset o f s e x u a l a c t i v i t y , and  not d e v i a t e markedly from t h e L.P.  group i n t o t a l energy i n t a k e .  changes i n t h e s k e l e t o n which would have been caused by t h e higher plane of n u t r i t i o n so no attempt was  so  slightly  i n t h e l a s t two months would be v e r y s m a l l  made t o e v a l u a t e t h e s e changes.  Any  and  The s k e l e t a l measure-  ments have been shown on t h e graphs t o i n d i c a t e t h e c l o s e agreement w i t h t h e L.P.  data. The H-L  results.  group o f two m a l e s , V 8 and V 26, produced  interesting  T h e i r t o t a l energy i n t a k e s at f o u r months were 186,166 and  198,330 C a l o r i e s , not t o o f a r d i f f e r e n t from t h e 200,000 C a l o r i e average o f t h e H.P.  group at f o u r months.  At s i x months, t h e t o t a l energy i n -  t a k e s were 320,725 and 336,612 C a l o r i e s , o r t h e e q u i v a l e n t o f a medium plane of n u t r i t i o n .  When t h e d a t a were p l o t t e d on t h e graphs o f %  versus t o t a l energy consumption f o r u n v a r i e d p a t t e r n s o f n u t r i t i o n , points f e l l tions w i l l  at v a r i o u s d i s t a n c e s t o t h e r i g h t o f t h e l i n e s .  The  G.I. the  devia-  be d i s c u s s e d f o r t h e same g r a d i e n t s as f o r t h e c o n s t a n t  planes  72.  of n u t r i t i o n :  fore-limb, hind-limb,  and vertebral column.  Fore-1imb: The points were displaced 109,000 Calories to the right of the curve for the fore-cannon, diminishing to 43,000 Calories for the scapula (Table 13). earlier.  This agrees c l o s e l y with the growth p r i o r i t i e s  discussed  At s i x months of age, the fore-cannon could achieve nearly  maximal s i z e on a medium plane of n u t r i t i o n . were H-L,  very l i t t l e growth could occur  If, however, the,pattern  in the last two months, because  the fore-cannon would then be a low p r i o r i t y area.  The  length of the  fore-cannon would remain close to the length of a four month H.P. cannon.  At the other end of the gradient, the scapula was  r e s t r i c t e d by the H-L pattern. the scapula was  fore-  not nearly so  In the period from four to s i x months,  a high p r i o r i t y region, and therefore grew in s p i t e of  the r e s t r i c t e d feed  intake.  H ind-1imb: The pattern in the hind-limb was  similar to that in the fore-1imb  except that the displacement from the standard  l i n e was  less for each  bone; i . e . , 94,000 Calories for the hind-cannon, as compared with 109,000 Calories for the fore-cannon.  This agrees with the thesis that the hind-  limb is s l i g h t l y later maturing than the fore-limb  (Huxley, 1932).  During  the period from four to s i x months, the hind-limb would have exhibited a higher p r i o r i t y for growth than the fore-limb, and therefore the energy r e s t r i c t i o n at this time would have produced a smaller growth decrement.  Table J j [ Average displacements of the growth increments of bone from H-L treated fawns from the standard curves (at 330,000 Calories)  Fore limb; Fore cannon Radius Humerus Scapula  109,000 Calories 109,000 81,000 43,000  Hind limb; Hind cannon Tibia Femur Pelvis  94,000 71,000 71,000 59,000  Vertebral length; Atlas Axis Cervical Cervical Cervical Thoracic Thoracic Thoracic Lumbar 1 Lumbar 3 Lumbar 5  3 5 7 1 5 10  65,000 34,000 94,000 72,000 57,000 45,000 51,000 82,000 69,000 81,000 105,000  74  Vertebral Column: 1.  Atlas and Axis  The atlas vertebra showed a moderate displacement  of 65,000  Calories, suggesting a r e l a t i v e l y high p r i o r i t y f o r growth between four and s i x months.  This bone also exhibited a high p r i o r i t y from zero to  four months, and apparently retained this f o r the f u l l s i x months.  The  axis was only displaced 34,000 Calories, indicating an extremely high p r i o r i t y during the last two months. from zero to four months.  Its growth p r i o r i t y was  also high  Measurements from these two bones should give,  a reasonable estimate of total energy consumption regardless of the pattern of alimentation.  That this cannot be used in this experiment w i l l  be shown later in 'Analysis of Unknowns . 1  2.  Other Vertebrae  The displacement  from the standard curves showed a decreasing  trend from c e r v i c a l 3 (94,000 Calories) to thoracic 1 (45,000 Calories) and then an increasing trend again to lumbar 5 (105,000 C a l o r i e s ) . indication here was  The  that the anterior and posterior regions had not  reached t h e i r periods of p r i o r i t y , and that the thoracic region was  be-  coming a region of high p r i o r i t y during the last two months.  C.  Analysis of Unknowns Estimation of the total energy consumption of unknown animals can  be accomplished  by comparing skeletal measurements of the unknowns at s i x  months of age with the curves of % G.I. versus total energy intake f o r the laboratory controls.  F i r s t of a l l , the measurements must be converted to  75.  the same % G.I. scale that is used on the graphs. expressed as a growth increment  Each measurement is  and then converted to a percentage of the  maximum growth increment f o r that bone.  These values can then be drawn  on to the graphs and the points of intersection with the standard  lines  measured. The estimated values for total energy intake from the intercepts should be l i s t e d according to the gradients discussed in the previous sections. apparent  A r e l a t i v e l y consistent value for total energy intake with no increasing or decreasing trends over the gradients would indicate  a constant plane of n u t r i t i o n , and an average of a l l values should give a r e l i a b l e estimate of total energy consumption.  An increasing trend from  d i s t a l to proximal regions of the limbs, and toward the middle section of the vertebral column would indicate a H-L pattern of a t t r i t i o n ; i . e . , the deviations from the standard lines would increase d i s t a l l y limbs, and anteriorly and p o s t e r i o r l y in the vertebral column.  in the This i n -  formation must, with the present limited number of standards, be evaluated subjectively to give an improved evaluation of total energy consumption.  Evaluation of Two Unknowns Two male fawns of the year were k i l l e d at Courtenay, B.C., December 1 9 , 1 9 6 5 . weighed  42.75  on  Each animal, one designated Field A and one F i e l d  pounds with a l l v i s c e r a , including l i v e r , removed.  B,  An  attempt has been made to evaluate the n u t r i t i o n a l h i s t o r i e s of these animals during their s i x month l i f e span. The total energy intercepts from the graphs of percent growth i n crement versus total energy intake are shown for each bone measurement from both animals  in Table 1 4 .  Also, the standard pattern of the intercepts  76.  T a b l e .14 I n t e r c e p t s o f t h e growth Increments o f F i e l d A and F i e l d B w i t h t h e s t a n d a r d c u r v e  Bone  A  Standard*  B  Fore cannon  227,000 C a l o r i e s  221,000 C a l o r i e s  225,000 C a l o r i e s  Radius  228,000  228,000  234,000  Humerus  309,000  256,000  255,000  Scapula  242,000  294,000  273,000  Hind cannon  268,000  244,000  251,000  Tibia  284,000  267,000  294,000  Femur  318,000  265,000  283,000  Pelvis  271,000  278,000  -  Atlas  261,000  272,000  307,000  Axis  374,000  304,000  397,000  Cervical 3  244,000  244,000  249,000  Cervical 5  272,000  265,000  333,000  Cervical 7  273,000  281,000  279,000  Thoracic 1  290,000  292,000  323,000  Thoracic 5  299,000  285,000  257,000  T h o r a c i c 10  268,000  255,000  281,000  Lumbar 1  -  267,000  258,000  Lumbar 3  323,000  255,000  295,000  Lumbar 5  264,000  232,000  274,000  P r o j e c t i o n o f H-L d a t a o n t o s t a n d a r d c u r v e s .  77.  obtained by p l o t t i n g the H-L % G.l.s against the standard curves is given, along with the differences between the f i e l d samples and the laboratory animals.  The f i r s t noticeable fact upon s u p e r f i c i a l examination of  the results was  that both animals had received a H-L pattern of  tion.  shown very well by the limb gradients, e s p e c i a l l y in  This was  F i e l d B.  The  alimenta-  increasing values for the intercepts in the proximal d i r e c -  tion indicated that the displacement from the standard  l i n e was  becoming  increasingly smaller in that d i r e c t i o n . Several consistent differences appeared between the laboratory H-L pattern and the f i e l d pattern of intercepts.  The differences between  the intercepts for the f i e l d animals and the laboratory controls were greater for the hind-limb  than for the fore-limb.  of the f i e l d animals had much higher the pattern.  The  Also, lumbars 3 and 5  intercepts compared with the rest of  intercepts of the axis, and to some extent the a t l a s ,  were also extremely high when compared to the rest of the data.  It must  be remembered, however, that the laboratory H-L pattern is purely a r t i f i c i a l , and  i t is u n l i k e l y that the pattern of alimentation  in the wild would cor-  respond very c l o s e l y to i t . In f a c t , a more reasonable model would be a decrease to a medium plane of n u t r i t i o n in August or September, becoming more and more severe later in the f a l l .  This might account for the d i f -  ferent pattern exhibited by the f i e l d animals. have permitted  A less severe L.P. would  greater growth of the later maturing areas, while  r e s t r i c t i n g regions that had passed their p r i o r i t y for growth. argument may  still This same  account for part of the greater growth in the atlas and axis,  but another factor also is of importance.  At b i r t h , the skull and  axis complex are regions of very high growth p r i o r i t i e s .  atlas-  Just following  78.  b i r t h , the animals for the laboratory were captured and  invariably s u f f e r -  ed some degree of depressed growth during the adjustment to c a p t i v i t y . is possible that the atlas-axis complex was had not recovered by s i x months of age. skull development.  It  stunted during this period  This  and  is d e f i n i t e l y the case with  De Bock (personal communication), in an investigation  of the skull dimensions of the animals from this laboratory as compared with f i e l d animals, found s i g n i f i c a n t l y smaller s k u l l s in the animals at s i x months of age.  This retardation was  laboratory  overcome in later  years. The % G.l.s for the bones (excepting the atlas and axis) from  H-L  treated laboratory animals when projected onto the standard curves gave a range of intercepts from 221,000 to 294,000 Calories total energy  intake.  The actual energy intakes for these animals averaged 330,000 Calories. The deviations, therefore, ranged from 36,000 to 109,000 Calories.  In the  f i e l d animals, the intercepts (excepting the atlas and axis) ranged from a low of 225,000 Calories to a high of 333,000 C a l o r i e s .  Over most of the  measurements, however, the intercepts for the unknowns were s i m i l a r to those of the controls.  Two  intercepts for the fore-limbs  ceeded the standards by 50,000 Calories. agreed c l o s e l y with the controls.  of F i e l d A ex-  For these same bones, Field B  In c e r v i c a l 5 and thoracic 1, F i e l d B  exceeded the controls by 60,000 and 30,000 Calories, but F i e l d A in these cases agreed c l o s e l y with the controls. had  Lumbars 3 and 5 in the unknowns  intercepts well above the controls, but t h i s was  mentioned.  expected as previously  Omitting the four measurements which deviated  from the controls  for only one or other of unknowns leaves the intercepts of the unknowns in quite close agreement with the controls, but perhaps 10,000 to 20,000  79  Calories higher.  T h i s would suggest a t o t a l energy  f o r t h e s e a n i m a l s around  350,000  i n t a k e over s i x months  C a l o r i e s of apparent  digestible  energy.  SUMMARY The o b j e c t i v e s of t h i s experiment 1.  t o i n v e s t i g a t e t h e sequence o f o c c u r r e n c e throughout t h e s k e l e t o n of t h e maximum p r i o r i t y f o r  2.  were:  growth;  t o d e t e r m i n e t h e e f f e c t of p l a n e o f n u t r i t i o n  and p a t t e r n o f  alimen-  t a t i o n on t h e e x t e n t of growth o f each r e g i o n o f t h e s k e l e t o n ; 3.  t o e s t a b l i s h a method by w h i c h t h e p l a n e of n u t r i t i o n  and  pattern  of a l i m e n t a t i o n e x p e r i e n c e d by a w i l d deer c o u l d be determined its  skeletal  growth.  The r e s u l t s o b t a i n e d 1.  indicated  that:  t h e d i s t a l t o p r o x i m a l , and a n t e r i o r  and p o s t e r i o r t o c e n t r a l  g r a d i e n t s d e s c r i b e d e l s e w h e r e f o r o t h e r mammals a p p l y a l s o t o 2.  t h e s k e l e t o n grew in a p r e d i c t a b l e manner w i t h each p l a n e o f t i o n and p a t t e r n of  3.  deer; nutri-  h i s t o r i e s of w i l d animals c o u l d be  a c c o m p l i s h e d w i t h a h i g h degree of a c c u r a c y by comparison t o standards.  growth  alimentation;  the a n a l y s i s of the n u t r i t i o n a l  atory  by  labor-  80.  BIBLIOGRAPHY Bandy, P.J. 1955 Studies of growth and n u t r i t i o n in the Columbian B l a c k t a i l deer. M.A. Thesis, University of B r i t i s h Columbia. Brody, S. 1945 Bioenergetics and Growth, with Special Reference to the E f f i c i e n c y Complex in Domestic Animals. New York, Reinhold. Cowan, I. McT., and A.J. Wood 1955 The growth rate of the Blacktail deer. Journal of W i l d l i f e Management 19: 331-336. French, C.E., L.C McEwen, N.D. Magruder, R.H. Ingram, and R.W. Swift 1956 Nutrient requirements for growth and antler development in the White-tailed deer. Journal of W i l d l i f e Management 20(3): 221. Czarrock, J . , I.R. Sibbald, and E.V. Evans 1961 The determination of chromic oxide in samples of feed. Canadian Journal of Animal Science 41: 167-179. Hammond, J . 1932 Growth and Development of Mutton Q u a l i t i e s in the Sheep. A Survey of the Problems Involved in Meat Production. Edinburgh and London, Oliver and Boyd. Huxley, J.S.  1932  Problems of Relative Growth.  London, Methuen.  Klein, D.R. 1964 Range-related differences in growth of deer reflected in skeletal r a t i o s . Journal of Mammology 45(2): 226-235. Lewall, E.F., and I. McT. Cowan 1963 Age determination in B l a c k - t a i l deer by degree of o s s i f i c a t i o n of the epiphyseal p l a t e in the long bones. Canadian Journal of Zoology 41: 629. McCay, C.M., M.F. Crowell, and L.A. Maynard 1935 The e f f e c t of retarded growth upon the length of l i f e span and upon the ultimate body s i z e . Journal of Nutrition 10: 63~79. McCay, CM., L.A. Maynard, G. Sperling, and L.L. Barnes 1939 Retarded growth, l i f e span, ultimate body s i z e , and age changes in the albino rat after feeding diets r e s t r i c t e d in c a l o r i e s . Journal of Nutrition 18: 1-13. McMeekan, C P . 1940 Growth and development in the p i g , with special reference to carcass q u a l i t y characters. I, II, III. Journal of Agricultural Science 30: 276-344, 387-436, 511-569. Morrison, F.B. 1956 Feeds and Feeding, a Handbook for the Student and Stockman. 22nd Ed. Ithaca, N.Y., Morrison Publ.Co. O'Keefe, J . J . 1957 Dry matter intake during early phases of growth for subspecies of deer (Odocoileus hemionus). M.A. Thesis, University of B r i t i s h Columbia.  81.  Palsson, H. 1 9 5 5 Progress in the Physiology of Farm Animals. London, Butterworths.  II.  Riney, T. 1952 New Zealand w i l d l i f e problems and status of w i l d l i f e research. New Zealand Science Review 1 0 ( 3 ) : 26-32. Schurch, A.F., L.E. Lloyd, and E.W. Crampton 1950 Chromic oxide determination of d i g e s t i b i l i t y . Journal of Nutrition 4 1 ( 4 ) : 6 2 9 - 6 3 6 . Wilson, P.N., and D.F. Osbourn Reviews 3 5 : 3 2 4 - 3 6 1 .  I960  Compensatory growth.  Biological  82.  APPENDIX  Diagrams o f t h e S k e l e t o n o f t h e Deer, w i t h t h e Measurements Used i n t h i s Experiment  FORE-CANNON:  R i g h t Leg  post.  v  ULNA-RADIUS:  R i g h t Leg  HUMERUS:  R i g h t Leg  SCAPULA:  R i g h t Leg  A n t e r i o r View  HIND-CANNON:  R i g h t Leg  TIBIA:  R i g h t Leg  FEMUR:  R i g h t Leg  PELVIS  ATLAS  anterior  Right  Side  Dorsal View  »  Right Side  CERVICAL VERTEBRAE  THORACIC VERTEBRAE T 10  Dorsal  View  LUMBAR VERTEBRAE L  5  L  3  D o r s a l View  

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0093628/manifest

Comment

Related Items