THE BLOOD PROFILES OF SOME EUROPEAN CATTLE BREEDS by BRUCE JAMES McGILLIVRAY B.Sc. (Agr . ) , Univers i ty of B r i t i s h Columbia, 1975 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (The Department of Animal Science) We accept th is thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA September, 1981 (c) Bruce James McGi l l i v ray , 1981 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y a v a i l a b l e for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It i s understood that copying or p u b l i c a t i o n of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Bruce J . McGILLIVRAY Department of Animal Science The University of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 September, 1981 DE-6 (2/79) i i ABSTRACT Blood samples drawn from 147 bulls representing ten European breeds from four a r t i f i c i a l insemination centres were analysed for fourteen blood serum t ra i t s . These were calcium, inorganic phosphorus, glucose, blood urea nitrogen, uric acid, cholesterol, total protein, albumin, total b i l i rub in , alkaline phosphatase, lac t i c dehydrogenase, serum glutamic-oxaloacetic transaminase, sodium, and potassium. The blood profi les compiled from these analyses were used to see i f the readily apparent phenotypic differences such as coat colour, s ize, carcass characterist ics, e t c . , which occur between different breeds of catt le were also accompanied by differences in their blood t ra i t levels. Several other effects were viewed as having a potentially signif icant influence On the blood t r a i t s . These included the reaction to handling stress (temperament), the effect of management unit (stud), and the individual ity of each animal's prof i le . Age at time of sampling was included as a covariable. Al l effects were subjected to analysis by least squares techniques. Repeatabilities were calculated which provided an indication of the influence of genotype on the blood t r a i t levels. The blood profi les of twelve half sib groups were compared to see i f blood t ra i ts under possible genetic control would exhibit less variation within groups of related animals than among unrelated animals. Correlating the blood profi les to several t ra i ts of economic importance provided insight into whether the profi les could be useful in the selection of breeding stock. The profi les of thirty-one Hoi stein bulls i i i were c o r r e l a t e d to t h e i r average daughter m i l k p roduc t ion var iab les . . The r e l a t i o n s h i p s between the blood p r o f i l e s and the growth t r a i t s were examined by comparing the mean blood p r o f i l e s o f seve ra l breeds to t h e i r r e spec t i v e growth t r a i t means. The ranges and means o f the blood t r a i t s compared qu i t e f avourab l y to the l i t e r a t u r e repor ted means f o r c a t t l e . Temperament was exc luded from the model because i t was i n s i g n i f i c a n t f o r a l l the blood t r a i t s . Age, through s i g n i f i c a n t f o r severa l b lood t r a i t s , was not b i o l o g i c a l l y impor tant . I t s c o n t r i b u t i o n to the model was very sma l l . Breed was not a major c o n t r i b u t i o n to the v a r i a t i o n of the blood t r a i t s . Of the fou r b lood t r a i t s w i th s i g n i f i c a n t breed e f f e c t s on l y u rea-N, and SGOT look p romis ing . Glucose and l a c t i c dehydrogenase have low r e p e a t a b i l i t i e s which i n d i c a t ed tha t t h e i r s i g n i f i c a n t breed e f f e c t probably occurred by chance. Between and w i t h i n i n d i v i d u a l v a r i a t i o n accounted f o r the ma j o r i t y o f the blood t r a i t v a r i a t i o n w i th envi ronmenta l f a c t o r s be ing an important component. The i n d i v i d u a l i t y o f the blood p r o f i l e s may prove use fu l i n the s e l e c t i o n o f breeding s tock . Urea-N and u r i c a c i d which had moderately h igh r e p e a t a b i 1 i t i e s c o r r e l a t e d to seve ra l growth t r a i t s . A l k a l i n e phosphatase was i nc luded i n the r eg res s i on equat ions o f m i l k y i e l d and p red i c t ed d i f f e r en ce f a t . More ex tens i ve breed d i f f e r en ce s i n the blood p r o f i l e s o f c a t t l e may come to l i g h t i n subsequent s t ud i e s i f s o r t i n g o f the breeds i n t o g e n e t i c a l l y s i m i l a r groups i s performed. Expansion o f the p r o f i l e to i n c l ude o ther enzymes and p r o t e i n f r a c t i o n s might a l s o prove f r u i t f u l . TABLE OF CONTENTS ABSTRACT LIST OF TABLES LIST OF ABREVIATIONS ACKNOWLEDGEMENTS INTRODUCTION LITERATURE REVIEW MATERIALS AND METHODS RESULTS AND DISCUSSION SUMMARY AND CONCLUSIONS BIBLIOGRAPHY APPENDIX V LIST OF TABLES TABLE PAGE 1 BREAKDOWN OF ANIMALS BY BREED, STUD, AND SAMPLING 31 2 BREAKDOWN OF ANIMALS AFTER SCREENING DATA 32 3 MODEL 1 EMS 33 4 MODEL 2 EMS 33 5 COEFFICIENTS OF DETERMINATION (R 2) FOR MODEL 1. 34 6 COEFFICIENTS OF DETERMINATION (R 2) FOR MODEL 2. 3 b 7 BREED LEAST SQUARES CONSTANTS OF BLOOD TRAITS AND GROWTH TRAIT INDICES. 3 6 8 HOLSTEIN PROGENY TESTS RESULTS 37 9 RANGES AND MEANS FOR AGE AND THE BLOOD TRAITS 39 10 BLOOD TRAIT LEVELS FROM THE LITERATURE FOR BULLS AND STEERS 4 0 11 BLOOD TRAIT LEVELS FROM THE LITERATURE FOR COWS 4 1 12 AGE REGRESSION COEFFICIENTS AND REPEATABILITYS 4 2 13 REPEATABILITYS FROM THE LITERATURE 4 3 14 CORRELATIONS BETWEEN ALL CONTINUOUS VARIABLES ^ 15 GROWTH TRAIT - BLOOD PROFILE CORRELATIONS 4 7 vi LIST OF ABBREVIATIONS ALB Albumi n ALKP A lka l ine phosphatase BILI Total b i l i r u b i n BURLINGTON A l l - West breeders, Bur l ington, Wash. B-WT B i r th weight Ca Calcium \ CALGARY B.C. A r t i f i c i a l Insemination, Calgary, A l t a . CHOL Cholesterol F-WT Final weight GLU Glucose I/B/S Individual with in breed within stud ICC Improved Contemporary Comparison K Potassium LDH Lact ic dehydrogenase MILNER B.C. A r t i f i c i a l Insemination, Mi lner , B.C. ME Metabolizable energy Na Sodium P Inorganic phosphorus POSADG Post-weaning average da i l y gain PREADG Pre-weaning average da i l y gain SGOT Serum glutamic-oxaloacetic transaminase TDN Total d iges t ib le nutr ients T.PROT tota l protein UREA-N Blood urea nitrogen URIC Ur ic acid WESTERN Western Breeders, Balzac, A l t a . W-WT Weaning weight ACKNOWLEDGEMENTS I wish at th is time to acknowledge those people whose e f fo r ts were of pa r t i cu la r importance in the completion of th i s thes i s . To Dr. J . Hodges, I express my gratitude for i n i t i a t i n g th is study and the supervision provided. To Dr. R. Peterson and Mrs. M. S t r i ke r , I owe my thanks for the considerable advice and aid given during the analys is of the data. I am also indebted to Dr. M. Hoque, Dr. J . Nyama, Mr. A. Gregson the s ta f f of the A . I . Centres, and the Health of Animals Veterinarians without whose help the blood sampling could not have occurred. F i na l l y , I wish to thank my family and fr iends for the i r encouragement and support. 1 INTRODUCTION There are many ca t t l e breeds in existence today. They have evolved by natural or a r t i f i c a l se lect ion to exh ib i t a wide d i ve r s i t y in the i r phenotypic t r a i t s . A r t i f i c i a l se lect ion was based on the pr inc ip le of l i k e begets l i k e (Rouse 1970). Crossing selected animals of each breed f ixed the desired charac ter i s t i cs of both breeds in the i r cross bred progeny. Breeding stock was then developed by inbreeding and se lect ion based on the desired t r a i t s , thereby, y i e ld ing a new breed of c a t t l e . It would be of in terest to know i f the wide phenotypic var iat ions which ex i s t between the d i f fe rent breeds for such t r a i t s as body colour, shape, s i z e , growth rate, carcass cha rac te r i s t i c s , e t c . , are accompanied by breed dif ferences in the blood const i tuents. In most blood studies of c a t t l e , breed i s usual ly a minor e f fect reported as an aside to the main object ives (Tumbleson et a l . , 1973 a,b; MacDonald et a l . ,1956; Kitchenham and Rowlands (1976). Two or three breeds, usual ly cows or young stock, are often the source of data. Re lat ive ly few researchers have reported on the blood p ro f i l e s of bu l l s , pa r t i cu l a r l y , in regards to differences between breeds (Russoff et a l . , 1954; Rowlands et a l . , 1977; Kunkel et a l . , 1953). This study attempted to invest igate th i s aspect of the phenotypic var ia t ion between breeds by comparing the blood p ro f i l e s of several European ca t t l e breeds. 2 S ign i f i can t differences between the blood p ro f i l e s of the breeds would indicate some sort of genetic control operating on the blood t r a i t s . Nash (1978) reported moderate h e r i t a b i l i t i e s for several blood t r a i t s in dairy cows. In the present study repea tab i l i t i e s were calculated for each blood t r a i t to give an ind icat ion of the extent of genetic cont ro l . They also provided an upper l im i t of the possible he r e i t ab i l i t y of each blood t r a i t . I f a blood t r a i t i s under genetic control then c lose ly re lated animals should have blood t r a i t leve ls grouping c loser together than would be evident in unrelated animals. The research of Ageraard and Katholm (1978), Ageraard (1978), Roubicek and Ray (1972), and Lane et a l . ,(1968) lend support to th i s hypothesis. The Hoi s te in bu l l s in the present study provided a number of ha l f s ib groups which were used to test the hypothesis. Those blood t r a i t s which show some degree of genetic control could prove useful in the se lect ion of breeding stock i f they corre late to other her i tab le t r a i t s which are of economic importance such as those pertaining to milk production, and growth. Stark et a l . , (1978) reported s ign i f i can t corre lat ions between the blood p ro f i l e s of Fr ies ian bu l l s and the i r daughter milk production var iab les . Several researchers have found s i gn i f i c an t corre lat ions between the blood and growth t r a i t s in ca t t l e (Pr ice et a l . ,1959; El-Sabban et a l . ,1971; Sengonca, 1977). Average daughter milk production data were ava i lab le for some of the Hoi s te in bu l l s in th i s study. This allowed for cor re la t ion of the blood p ro f i l e s of those bu l l s to the i r average daughter milk production. 3 v a r i a b l e s . Da ta on t h e g rowth t r a i t s o f s e v e r a l b r eeds were g l e a n e d f r om t he l i t e r a t u r e and c o r r e l a t e d t o t h e mean b l o o d p r o f i l e s o f t h e s e b r eeds t o l o o k f o r p o s s i b l e r e l a t i o n s h i p s between t he g rowth and b l o o d t r a i t s . 4 LITERATURE REVIEW Breed The reports from the l i t e r a tu re in regards to the presence or absence of breed differences in the blood t r a i t s of ca t t l e are r e l a t i v e l y few. Russoff and Piercy (1946) were unable to detect any breed differences between Hoi s te in and Jersey cows for calcium and phosphorus. Long et a l . (1952) had s im i la r resu l ts with Angus, Hereford, and Shorthorn cows and heifers as did Russoff et a l . (1954) with Jersey, Guernsey, and Holste in bu l l s . Kitchenham and Rowlands (1976) found s i gn i f i can t dif ferences between the blood leve ls of calcium, potassium, and tota l protein of Ayrshire and Fr ies ian cows. Sikes (1963) reported a s i gn i f i can t breed ef fect for the phosphorus leve ls of Guernsey, Jersey and Holstein c a t t l e . Tumbleson et a l . (1973 a) found no s i gn i f i can t dif ferences between Holstein and Guernsey cows for phosphorus, sodium, potassium and urea-N but calcium leve ls were s i gn i f i c an t l y higher in the Guernsey breed than the Holste in. Using Afr ikaner and Fr ies land c a t t l e , Heyns (1971) found no breed differences for potassium and sodium but did f ind lower calcium and glucose leve ls in Afr ikaner c a t t l e . MacDonald et a l . (1956) reported that Angus calves general ly had higher leve ls of u r i c ac id than Hereford ca lves. Working with Devon, Sussex, Hereford, and Lincoln Red bu l l s Rowlands et a l . (1977) found s i gn i f i can t breed differences for glucose, urea-N, calcium, and sodium. 5 Hereford had calcium, urea-N, and albumin leve ls lower than the other breeds while the i r phosphorus leve ls were higher. Tumbleson e ta l . (1973b) in a study involv ing Guernsey and Holstein female dairy ca t t l e reported no s i gn i f i c an t breed differences for serum tota l prote in , albumin, urea-N, l a c t i c dehydrogenase, and SGOT. The level of a lka l ine phosphatase was s i gn i f i c an t l y higher in Guernseys than Holste ins. Heyns (1971) also reported breed differences for a lka l ine phosphatase. Albumin and a lka l ine phosphatase were higher in Afr ikaner ca t t l e than Fr ies land. Russoff et a l . , (1954) found a s i gn i f i can t breed ef fect for a lka l ine phosphatase among Jersey, Guernsey, and Holstein bu l l s . Kunkel et a l , (1953), on the other hand, found no s i gn i f i can t dif ference between Angus, Hereford, Jersey, and Holstein ca t t l e for a lka l ine phosphatase or between beef and dairy types. Pr ice (1959) found that Hereford male calves had lower averages for albumin than Angus males, there were no breed differences in plasma proteins: for female c a t t l e . Tumbleson et a l . , (1973 a) reported no breed differences between Holstein and Guernsey for urea-N. Kitchenham and Rowlands(1976) found no breed differences between Ayrshires and Fr iesfan cows for urea-N. Kitchenham and Rowlands (1976) reported that leve ls of to ta l protein were s i gn i f i c an t l y d i f fe rent between Ayrshire and Fr ies ian cows. Albumin leve ls were not s i gn i f i c an t l y d i f fe rent . Tumbleson et a l . (1973 b) could f ind no differences between Holsteins and Guernseys for tota l protein and albumin, while Rowlands et a l . , (1977) found breed differences among several beef breeds for albumin. 6 Individuals, Kitchenham and Rowlands (1976) and Rowlands et a1 . , (1975) reported s i gn i f i can t differences between indiv idual dairy cows for glucose, calc ium, potassium, sodium, phosphorus, urea-N, albumin, and tota l prote in. They concluded that animals have ind iv idua l patterns of blood chemistry which may change with age. Var iat ion between herds accounted for most of the var ia t ion of glucose, urea-N, phosphorus, calcium, sodium, potassium and albumin in a study reported by Payne et a l . , (1973). The resu l ts of a study by Rowlands et a l . (1974 a) suggested that calves have ind iv idual blood p ro f i l e s . Differences among calves were s i gn i f i can t for a l l blood t r a i t s (glucose, urea-N, albumin, phosphorus, calcium, sodium, potassium). A major part of the var ia t ion was within calves; showing a need for repeated samples. Stark et a l . (1978) in a study with 172 Fr ies ian bu l l s found s i gn i f i can t differences between bu l l s with in studs and age groups for glucose, urea-N, albumin, phosphorus, calcium and potassium. Sodium was not s i gn i f i c an t . Kitchenham et a l . (1977) reported s im i la r resu l ts for albumin and sodium in a study with bu l l s and steers. Gartner et a l . (1966) working with grazing Hereford ca t t l e found sodium and potassium to be i n s i gn i f i c an t for ind iv idua ls and phosphorus and calcium to have a high sampling variance. Russoff and Piercy (1946) also reported s i gn i f i c an t monthly var ia t ion for calcium and phosphorus within dairy cows as well as s i gn i f i can t ind iv idual va r i a t i on . Lennon and Mixner (1957) reported that the var ia t ion among animals accounted for 90.07% of the tota l 7 var ia t ion of cholesterol in dairy c a t t l e . Dai ly var ia t ion accounted for less than 1% and diurnal 2,79%. Crookshank et a l . (.1952), Russoff et a l . (1954), and A l l c ro f t and Fo l ley (1941) reported a lka l ine phosphatase to vary widely from animal to animal but remain r e l a t i v e l y constant within animals. Environmental factors contr ibute to ind iv idua l var ia t ion as evidenced by the numerous research papers published on th i s top ic . Handling s t ress , d iu rna l , seasonal and monthly va r i a t i on , semen co l l e c t i on , nu t r i t i on , sample storage, water intake, and the proximity of feeding and sampling times a l l contribute to the var ia t ion between ind iv idua ls and between repeated samples of an i nd i v i dua l . The ef fects of handling stress (temperament) have been reported by Palmer et a l . (1930) and Gartner et a l . (1969). Palmer et al.(1930) found phosphorus to increase af ter vigorous exercise followed by a marked decrease af ter ha l f an hour to a point below the level pr io r to the exercise and remain low for at least two hours. Gartner et a l . (1969) was unable to f i nd any consistent e f fect of exc i ta t ion and exercise on the level of phosphorus. The changes in tota l protein were small but s i gn i -f i can t . Potassium was unaffected. Water depr ivat ion af fects the leve ls of urea-N and sodium in dairy cows. L i t t l e et a l . (1976) reported the leve ls of urea-N and sodium increased with the degree of water depr ivat ion. Palmer et a l . 8 (1930) reported wide day to day f luctuat ions hut that water intake had no ef fect on phosphorus l eve l s . Spate e t a l . (1970) invest igated the ef fects of storage time and temperature on the concentrations and a c t i v i t i e s of bovine serum const i tuents. They reported that storage for up to four weeks at -10° did not af fect the concentrations of glucose, cho les te ro l , b i l i r u b i n , to ta l prote in , c reat in ine , blood urea nitrogen, sodium, and potassium. Cloudiness caused by bacter ia l contamination occurred af ter only one week of storage at 2°. The enzymes, a lka l ine phosphatase,SGOT and l a c t i c dehydrogenase, were the least s tab le . Spate et a l . , (1970) recommended that enzyme assays should be completed as soon as possible a f ter sample co l l e c t i on . Calcium and phosphorus concentration exhibited a sharp increase af ter ten days in storage at -10°. The refr igerated samples had elevated leve ls even ea r l i e r (day 3). The proximity of feeding and sampling w i l l have had some ef fect on the blood t r a i t s of some animals. According to Kennedy et a l . (1939) glucose leve ls r i s e a f ter feeding then decrease. Palmer et al.(1930) reported a small but s i gn i f i can t increase in phosphorus within the f i r s t hour of food ingest ion which pers isted for about two hours followed by a decrease to the level pr io r to eat ing. Coggins and F ie ld (1976) found that the leve ls of glucose and urea-N were affected by feeding. Glucose decreased rap id ly a f ter feeding followed by a slower increase. Urea-N increased af ter feeding to a peak level about eight hours l a t e r . 9 Coggins and F ie ld (.1976) reported s i gn i f i c an t diurnal var ia t ion in glucose, urea-N, albumin, and calcium, pa r t i cu l a r l y for glucose and urea-N. Most of the var ia t ion was associated with feeding. Phosphorus and tota l protein were not s i gn i f i c an t . Palmer et a l . (1930) and Palmer and Eckles (1930) reported no s i gn i f i c an t diurnal var ia t ion discernable in dairy ca t t l e for phosphorus and calcium but wide day to day f luctuat ions were apparent. A s i gn i f i c an t but small (< 1%) port ion of the var ia t ion of cholesterol in dairy ca t t l e can be at t r ibuted to diurnal var ia t ion according to Lennon and Mixner (1957). A number of researchers have reported the existence of seasonal and monthly var ia t ion in the blood t r a i t s . Manston et a l . (1977) found s i gn i f i c an t seasonal differences in calcium, sodium, potassium, phosphorus, glucose, urea-N, and albumin in bu l l s and steers . Rowlands et a l . (1974 b) detected seasonal patterns in urea-N. Smaller seasonal ef fects were observed for albumin, glucose, calcium, phosphorus, sodium, and potassium. Lane et a l . (1968) also reported seasonal ef fects fo r calcium and phosphorus. Dairy ca t t l e in Louisiana did not exh ib i t seasonal ef fects for calcium and phosphorus (Russoff and P iercy, 1946). The warmer cl imate in that area may not predispose the ca t t l e to as great a seasonal var ia t ion as perhaps a more northerly c l imate. Van Landingham et a l . (1942) also found seasonal var ia t ion in the phosphorus leve ls of dairy ca t t l e with higher leve ls in the warmer months. Conversely, l a c t i c dehydrogenase was highest in the winter months in a study by Roussel and S ta l l cup (1967). In an e a r l i e r study with Holstein bu l l s they reported SGOT and a lka l ine phosphatase to be 10 at the i r highest leve ls in the summer. In Guernsey cows, urea-N peaked in the spring and was lower in the winter (Lane and Campbell, 1966). Russoff et a l . (1954) reported a s i gn i f i c an t monthly var ia t ion in calcium and a lka l ine phosphatase leve ls while phosphorus did not vary s i gn i f i c an t l y from month to month in dairy c a t t l e . Stufflebeam and Lasley (1969) detected a small seasonal e f fect in the cholesterol of Hereford bu l l s and cows. Cholesterol was lowest in the summer and highest in the winter. Semen co l l e c t i on according to Reid et al.(1947) and Reid et a l . (1948 b) has a strong inf luence on the plasma leve ls of a lka l ine phosphatase in bu l l s . They reported the fol lowing highly s i gn i f i can t negative corre lat ions between a lka l ine phosphatase and semen var iab les: ALKP - # ejaculates/day - 0.71 ± 0.06 ALKP - volume/day - 0.83 ± 0.04 ALKP - # spermatozoa/day x 10 8 - 0.86 ± 0.03 A lka l ine phosphatase leve ls in a bul l never co l lected from ranged from 18.04 to 19.75 units with a mean of 18.95 un i ts . After co l l e c t i on of nine samples over 16 days (193 ml or 4.14 b i l l i o n spermatozoa) a l ka l i ne phosphatase dropped to 5.24 un i t s . They concluded that the quantity or frequency of semen ejacu lates, more pa r t i cu l a r l y the number of spermatozoa, produced by the bu l l s i s the major factor determining the level of a lka l ine phosphatase in the blood plasma. Nut r i t iona l factors have been reported by numerous researchers to inf luence the leve ls of blood t r a i t s . L i t t l e and Manston (1972) looked at the ef fects of feeding maize and lucerne s i lages on the blood composition of dairy c a t t l e . They found serum albumin and 11 urea-N to be higher in the lucerne fed cows which they at t r ibuted to the higher leve ls of d iges t ib le prote in . The maize fed cows had higher phosphorus l eve l s . Phosphorus they concluded was more avai lab le in the maize than lucerne s i l ages . Ruppanner et al.(1978) found urea-N to be higher in calves on feedlot fed rat ions higher in prote in. Belyea et al.(1975) reported urea-N in Holstein dairy cows to r i se with increased grain (protein) intake. Manston et a l . (1975), Prewitt et a l , (1971), and Blowey et a l . (1973) had s im i la r resu l t s . Morris and Swan (1976) had a strong corre lat ion between nitrogen intake and urea-N (r = 0.80) in the Fr ies ian cows of the i r study. Glucose was not related to food intake. Blowey et a l . (1973) found glucose to vary with the starch intake while serum albumin followed the trends of protein intake. Hassan and Roussel (1975) reported tota l protein was unaffected by changes in the protein leve l of the d iet of the i r Holstein cows. Albumin and glucose increased with a r i s e in d ietary prote in . Glucose, phosphorus, and urea-N were lower in calves on a conventional system of rearing compared to a rapid rearing system (Kitchenham et a l . , 1975). Lane and Campbell (1966) reported that in Guernsey cows urea-N peaked in the spring time when the ca t t l e were on pasture and was at i t s lowest during the winter months. Ur ic ac id and to ta l protein levels increased in Hereford ca t t l e on range when the i r feed supply improved. Ur ic acid decreased during times of nu t r i t i ona l s t ress . (Roubicek et a l . , 1970; Roubicek and Ray, 1972). 12 Stufflebeam et a l . (1969) reported that energy intake affected the leve ls of the blood t r a i t s in beef he i fe r s . Total prote in , and cholesterol decreased with a lowering of the energy intake while phosphorus and potassium increased. Glucose and sodium were not great ly af fected. Stufflebeam and Lasley (1969) found the cholesterol levels of Hereford cows and bu l l s decreased with a lower energy intake. Ration did not have any s i gn i f i can t e f fect on cholesterol leve ls in Holstein cows and hei fers (Arave et a l . , 1975). The calcium leve ls of Hereford, Shorthorn and Angus cows and hei fers fed mineral supplements were unaffected by d ie t . Their phosphorus leve ls were affected by d ie t (Long et a l . , 1952; Fisher et a l . ,1972). McMillen and Langham (1942) reported that Hereford ca t t l e had lower phosphorus leve ls on wheat pasture than when on dry l o t . Van Landingham et a l . (1935, 1936) concluded that a low phosphorus d ie t resulted in a lowering of the phosphorus level of the blood and that phosphorus intake had no ef fect on the calcium level of the blood of dairy cows. Devlin et a l . (1969) in a.study with year l ing Hereford steers found dietary potassium to have no ef fect on the blood leve ls of calcium, phosphorus and sodium. Serum potassium concentrations were lowered by a low potassium d ie t . Gahne (1967) and Reid et a l . (1948 a) both reported a lka l ine phosphatase to be unaffected by plane of nu t r i t i on and feed type. Horn et a l . (1977) found the tota l protein of steers to be unaffected by fas t ing . Urea-N decreased in animals fast ing longer than twelve hours. 13 AGE Age has been reported by a number of researchers to exert a s i gn i f i c an t inf luence on the leve ls of the blood t r a i t s . Peterson (1974) reported a decl ine in a l ka l ine phosphatase with age in growing Hereford bu l l s . Lact ic dehydrogenase increased with age. Roussel and Sta l lcup (1966, 1967) reported s im i la r f indings for a l ka l ine phosphatase in young Holste in Fr ies ian bu l l s but that l a c t i c dehydrogenase decreased with age. SGOT was not s i gn i f i c an t l y af fected. Sengonca (1977) in a study involv ing th i r t y - fou r bu l l s from the Angeln, Simmental, Ho l s te in -F r ies ian , and Brown Swiss breeds found a lka l ine phosphatase to increase with age. Tumbleson et al.(1973 a and b) reported on the changes in the blood t r a i t s of 510 Guernsey and Holstein female ca t t l e which ranged in ages from one month to sixteen years. They found a lka l ine phosphatase to decl ine with age. Lact ic dehydrogenase increased s i gn i f i c an t l y from less than s ix months to 2 years of age. Thereafter i t decreased s i gn i f i c an t l y from 2 to more than 10 years of age. SGOT was not s i gn i f i c an t l y affected by age. Reid et a l . (1948b) were unable to detect a s i gn i f i can t age e f fec t for a l ka l i ne phosphatase in dairy bu l l s (17 to 128 months o ld ) . Reid et a l . (1948a) were unable to detect an age ef fect on a lka l ine phosphatase in Holstein bu l l s (18 to 33 months o ld ) . 14 Arthaud et a l . (1959) found no s i gn i f i can t age ef fect for glucose in beef bu l l s (Angus, Hereford, and Shorthorn) during the ages of s ix months to one year. Stark et a l . (1978) looked at the ef fects of age on the blood composition of 172 Fr ies ion bu l l s from one to fourteen years o ld . They also found no s i gn i f i can t age ef fect for glucose. Urea-N, sodium, and potassium were also not s i gn i f i c an t l y af fected. Tumbleson et a l . (1973a) reported urea-N to increase with age in dairy c a t t l e , and potassium to decrease. Sodium was not af fected. Calcium and phosphorus decreased with age (Stark et a l . , 1978; Tumbleson et a l . , 1973a). Reid et a l . (1948a) found that phosphorus decreased and calcium increased with age in twelve Holstein bu l l s (18 to 33 months o ld ) . Tumbleson et a l . (1973b) reported tota l protein to increase with age. Albumin was not af fected. Stark et a l . (1978) found a s i gn i f i c an t quadratic e f fect for albumin. Albumin concentration increased fron one to f i ve years then decreased. Nash (1978) found s i gn i f i c an t age ef fects for tota l prote in , urea-N, phosphorus, calcium, a l ka l i ne phosphatase, and sodium in dairy c a t t l e . Peterson and Waldern (1981) reported s i gn i f i can t age ef fects for cho les tero l , glucose, and l a c t i c dehydrogenase in dairy cows. 15 Growth Performance Correlat ions Colby et a l . (1950) reported no s ign i f i can t corre lat ions between the rate of gain in beef calves and the i r blood concentrations of urea-N and glucose. The bu l l calves had a corre la t ion of 0.98 for cholesterol and rate of ga in. Their l imi ted data on heifers gave a non-s ign i f icant co r re la t i on . Arave et a l . (1975) had a cor re la t ion of 0.21 for cholesterol and body weight in dairy c a t t l e . Using Hereford bu l l s , Stufflebeam and Lasley (1969) found a low cor re la t ion of cholesterol to body weight but a s i gn i f i c an t genetic cor re la t ion between cholesterol and post-weaning growth rate (0.63) which ind icated, in the i r opin ion, that some of the same genes af fect both t r a i t s and that environmental factors were also important sources of va r i a t i on . Prince (1959) reported urea-N was highly correlated to gain and food u t i l i z a t i o n e f f i c i ency in Hereford and Angus calves. In another study using Hereford and Angus calves Pr ice et a l . (1959) found urea-N s i gn i f i c an t l y corre lated to rate of gain (-0.31). Kitchenham et a l . (1977) reported s i gn i f i can t pos i t i ve corre lat ions for growth rate and f i na l weight (0.44 and 0.38). Pr ice et a l . (1959) found ur ic acid was s i gn i f i c an t l y correlated to rate of gain at both 500 and 800 lbs for Hereford and Angus calves (-0.30 and -0.35). Albumin was not s i gn i f i c an t . Kitchenham et a l . (1977) reported that for bu l l s and steers albumin and potassium were s i gn i f i c an t l y corre lated to growth rate and 16 f i na l Weight but when the data were adjusted for I n i t i a l weight the corre la t ions were i n s i gn i f i c an t . S ign i f i cant corre lat ions of 0.36 or greater between weight gain and glucose, phosphorus, sodium and albumin in he i fer calves 6 - 1 3 weeks old became i n s i gn i f i c an t when the data were adjusted for tota l feed intake. Kitchenham et a l . (1975) had dairy calves on a conventional rearing system. Their growth rates correlated s i gn i f i c an t l y with serum phosphorus whereas the calves on a rapid rear ing system did not have any blood t r a i t s cor re la t ing s i gn i f i c an t l y to growth. They concluded that the re lat ionships between rate of growth and blood chemistry appeared to depend on the level of nu t r i t i on . Some re lat ionships may occur only when the dietary intake of a par t i cu la r nutr ient i s a l im i t i ng factor to rate of growth. Their resu l ts and conclusions agree with those of L i t t l e et a l . (1977) mentioned ea r l i e r . L i t t l e et a l . (1977) concluded that feed intake was the dominant factor which accounted almost en t i r e l y for the s i gn i f i can t corre lat ions between weight gain and blood composition that were observed. Their corre lat ions became i n s i gn i f i c an t when adjusted for tota l feed intake. They further concluded that the corre lat ions were un l ike ly to be useful for the se lect ion of stock with improved feed conversion e f f i c i ency because of the lack of any s i gn i f i can t corre lat ions between feed conversion ra t io and the concentration of any blood t r a i t . Rowlands et a l . (1974a) reported a negative cor re la t ion between potassium and growth rate and body weight in Holste in-Fr ies ian calves but in a study involv ing bu l l s , Rowlands et al.(1977) 17 were unable to detect any s i gn i f i can t corre lat ions to rate of growth wi th in breed. El-Sabban et al.(1971) found that SGOT corre lated s i gn i -f i c an t l y with body weight (-0.28) and metabolic weight (-0.21). Peterson (1974) said l a c t i c dehydrogenase was not important i n explaining the var ia t ion of weight or weight gain. A lka l ine phosphatase was reported by several researchers to corre late s i gn i f i c an t l y to the growth t r a i t s . A lka l ine phosphatase correlated s i gn i f i c an t l y to rate of gain (0.54) in Ho ls te in-Fr ies ian calves in a study done by Alexander et a l . (1958). Another by Ageraard (1978) involv ing calves had a corre la t ion of 0.30 between plasma a lka l ine phosphatase and da i l y gains with the highest gains shown by calves with highest a lka l ine phosphatase a c t i v i t i e s . Kruger and Lakanc (1968) found indicat ions that Black Pied Lowland bul l calves with high i n i t i a l a l ka l i ne phosphatase a c t i v i t i e s had higher da i l y weight gains in the subsequent fattening period (r = 0.81). Female calves had a negative corre la t ion (-0.29). Sengonca (1977) found s i gn i f i can t corre lat ions of a l ka l ine phosphatase to average da i l y gain, carcass weight, dressing percentage and l o in eye area in Simmental, Ho ls te in -Fr ies ian , and Brown Swiss c a t t l e . Kunkel et a l . (1953) reported s ign i f i can t corre lat ions with feed e f f i c i ency (-0.63) feed intake per pound of body weight (-0.60) and rate of gain (-0.56) in Hereford and Angus bu l l s . 18 Progeny Tests In a study involv ing blood samples drawn from 172 Fr iesfan bu l l s , Stark et a l . (1978) reported s ign i f i can t corre lat ions to ex i s t among the blood concentrations of urea-N, phosphorus, and potassium and the Improved Contemporary Comparisons (ICC's) for milk y i e l d . Their mult ip le regression analysis showed that the inc lus ion of g lobul in and potassium in the regression equation was s i gn i f i c an t . They found no s i gn i f i c an t re lat ionships between ICC for butter fat y i e l d , butter fat percentage or protein y i e l d and blood concentrations. Related Animals Lane et al.(1968) reported s ign i f i can t s i r e ef fects in Guernsey cows for phosphorus, sodium, and potassium. Calcium was not s i gn i f i c an t l y af fected. Kitchenham et a l . (1975) working with dairy calves also found s i gn i f i c an t s i r e ef fects for sodium, potassium, and calcium but phosphorus was not s i gn i f i c an t l y af fected. Glucose was. s i gn i f i c an t l y affected while urea-N and albumin were not. Their resu l ts agree with those of Lane and Campbell (1966) for urea-N but not those of Plum and Schultze (1958) for glucose and those of Roubicek and Ray (.1972) for albumin. Roubicek and Ray (1972) also found tota l protein to be affected s i gn i f i c an t l y by s i r e . Working with Hereford ca t t l e Roubicek et a l . (1970) concluded genetic inf luence to be of l i t t l e importance on the leve ls of ur i c acid under the uncontrol led environmental condit ions of ca t t l e on range. Wilson and Dinkel (1968 b) 19 reported s im i la r conclusions with regards, to the blood composition of Hereford steers. They concluded that ranch ef fects were much more important than s i re d i f ferences, thus ind icat ing that permanent environmental deviations have a larger e f fect on most t r a i t s of blood composition than addit ive gene di f ferences. Arave et a l . (1975) and Stufflebeam and Lasley (1969) reported s i gn i f i can t s i re ef fects for cholesterol in Holstein cows and he i fe rs , and beef ca t t l e respect ive ly . Ageraard and Katholm (1978) and Ageraard (1978) both found s i gn i f i c an t l y smaller var ia t ion in a lka l ine phosphatase a c t i v i t y of calves within hal f s ib groups. Sengonca (1977) reported that a lka l ine phosphatase was not s i gn i -f i c an t l y affected by genotype in Ho ls te in -Fr ies ian , Simmental, Brown Swiss and Angeln bu l l s . 20 MATERIALS AND METHODS Data Co l lect ion The source of blood for th i s study was the bu l l s of four A . I . centers. These were: a. A l l - West Breeders of Bur l ington, Washington, b. Western Breeders of Balzac, A lber ta , c. BCAI of Mi lner , B.C., and d. BCAI of Calgary, A lber ta . These studs w i l l be referred to as Bur l ington, Western, Mi lner , and Calgary, respect ive ly , for the remainder of th i s paper. The A . I . centers offered the ohly read i ly accessible source of d i f fe rent breeds of c a t t l e . Other advantages offered included: 1. Some degree of uniformity of management between centres, 2. Pure bred animals with records of b i r t h , heal th, and ancestry, and 3. The blood p ro f i l e s of bu l l s are not affected by l a c ta t i on , pregnancy, and estrous as in the case of cows. Samples were drawn from 277 bu l l s representing 23 breeds during the spring and summer of 1976. A breakdown of the samples by breed, stud, and s ing le and paired samples i s presented in Table 1. Two v i s i t s to each stud were made about a month apart. Approximately 50 ml of blood were drawn from the jugular vein or coccygeal vein and/or artery into 20 ml vacutainer tubes. The s i t e of blood sampling was dependent on the veter inar ian drawing the blood. The veter inar ians at Burl ington and Mi lner bled the bu l l s from the neck while at Western and Calgary 21 bu l l s were bled from the t a i l . S i te of sampling was therefore confounded with stud e f fec ts . This may have had some ef fec t on the resu l ts for phosphorus which according to Parker and Blowey (1974) and Teleni et al .(1976) i s s i gn i f i c an t l y higher (12%) in the coccygeal vessels than the jugular ve in. The blood was allowed to c l o t upright in racks pr io r to centr i fuging for twenty minutes at about 3,000 rpm in p l a s t i c centr i fuge tubes. The serum was then pipetted into a second centr i fuge tube,spun for another ten minutes and stored in p l a s t i c s c i n t i l l a t i o n v i a l s . The samples were refr igerated at the A . I . centre unt i l t ransfer to freezing f a c i l i t i e s was possible which in the case of Burl ington and Mi lner was the same day. The samples from the other studs were ref r igerated during the sampling period of each t r i p and frozen pr io r to departure for Vancouver. The samples were packed in ice during the twelve hour return t r i p . Concurrent with sampling, each animal was assessed on a scale of one to three for i t s temperament, i . e . degree of calmness in response to sampling. A calm animal scored a one while an excited animal received a three. A two was reserved for animals judged to be somewhere between calm and exc i ted. B i r th date and weight at sampling were recorded. Many of the weights were estimates provided by the s ta f f of the A . I . centre. Weighing of the dairy breeds i s an infrequent occurence. I t was l a te r decided not to include weight as a covariable for th is reason. 22 Blood p ro f i l e s were compiled from the analys is performed by the technicians of B.C. Bio-Medical Laboratory in Burnaby on a multichannel sequential analyser. The leve ls of fourteen blood t r a i t s were deter-mined by the procedures described by Peterson and Waldern (1981), and Nash (1978). These were: 1. Calcium (Ca) 2. Inorganic Phosphorus (P) 3. Glucose (GLU) 4. Blood Urea Nitrogen (Urea-N) 5. Ur ic Acid (URIC) 6. Cholesterol (CHOL) 7. Total Protein (T. PROT) 8. Albumin (ALB) 9. Total B i l i r ub i n (BILI) 10. A lka l ine Phosphatase (ALKP) 11. Lact ic dehydrogenase (LDH) 12. Serum glutamic-oxaloacet ic Transaminase (SGOT) 13. Sodium (Na) 14. Potassium (K) S t a t i s t i c a l Technique The data were screened for ou t l i e r s and missing observations. Two or three animals were lacking test resul ts on some of the i r blood t r a i t s while-another s ix were found upon p lo t t ing the data to have f i ve or more of the i r blood t r a i t s showing leve ls considerably higher 23 or lower than the res t . Also excluded were animals with a s ingle blood sample because weighting of s ingle and paired samples would have been necessary, thereby great ly increasing the complexity of the ana lys i s , and contr ibut ing nothing to the repeatab i l i t y ca lcu lat ions or res idua l . Breeds which had f i ve or fewer animals with repeated samples were not included. This was an arb i t ra ry l im i t designed to maximize the number of breeds, yet s t i l l include those which have enough animals to y i e l d a somewhat representative sample of the breed. Ten breeds were l e f t in the study (Table 2) . At least squares analys is of variance technique for unequal subclass numbers as described by Harvey (1975) was used to analyse the data. Temperament proved to be i n s i gn i f i can t for a l l the blood t r a i t s and was therefore excluded from the model. Breed, stud, and ind iv idua l ef fects were f i t t e d . Age was included as a covar iable. In order to f i t ind iv idua ls i t was necessary to screen the data again to remove animals that changed stud between sampling and those which were the only animal of a breed with in a stud. Table 2 displays the resul ts of th i s f i na l screening of the data. As a resu l t Angus had been reduced to f i ve ind iv idua l s . The model i s given below. 24 Model 1 and Y i j k l where: Y. i j k l cx = B f = S, = L k ( i j ) Mjk l i j k l a + B i + S j + 1 k ( i j 1 + b i Mm + E e j k l the 1 th observation of the i th breed, j th stud, and k th i nd i v idua l ; the overal l mean when -j^ i s equal to zero; the breed, i = 1, 2, 3, . . . 10; the stud, j = 1, 2 . . . 4; the k th ind iv idual nested within the i th breed and the j th stud; the regression of the dependent var iable on the independent continuous var iable A^-j each time holding , the f i t t e d d iscrete var iab les , breed (B.)» stud (S.) and ind iv idua ls (1 )^ constant; the age in days at time of sampling for the corresponding Y i j k l ; the random er ror , NID (0,v2) (1 = 1, 2). Breed and stud were assumed to be f ixed e f fec ts . Individuals was a random e f fec t . The test ing term for breed and stud was ind iv idua ls . Individuals was tested against the res idua l . When ind iv idua ls was i n s i gn i f i can t i t was pooled with the residual and the pooled term used as the test ing term for breed and stud. This subset of model 1 i s given below. It i s ca l led model 2 for convenience sake. 25 Model 2 Y i j k = a + B i + s j + B i : ( A ) f j k + e i j k Where: Y.. . = the k th observation in the i th breed and the j th stud; i j k a - the overa l l mean when A... i s equal to zero; IJK B i = the breed, i = 1, 2, 3, . . . 10; S. = the stud, j = 1, 2 . . . 4; J b. = the regression of the dependent var iable Y.. . on the inde-pendent continuous var iable A. .. holding the f i t t e d 1 J K discrete var iab les , breeds (B.) and stud (S.) constant; A i j k = t h e a 9 e i n ^ a y s a t t n e t i m e o f s a m P l i n 9 f ° r t h e corresponding Y.. . ; I J K i j k The expected mean squares for Models 1 and 2 are displayed in Table 3" and 4, respect ive ly , where B = # of breeds, S = # of studs, n = # of samples and I i s a summation of degrees of freedom for each breed stud c lass ; i . e . , summing the number of ind iv idua l s , less one, for each breed stud c lass . There were 21 breed stud c lasses, therefore, 21 degrees of freedom were l os t for ind iv idua l s . The K value was 2 because these were two samples per animal (Becker, 1975). and e.-i, = the random er ror , NID (0 ,v 2 ) (k = 1 , 294) 26 Repeatabi1i t i es Repeatab i l i t ies were calculated from Model 1 by the method given by Becker (1975). v 2 Repeatabi l i ty = R = v + w E ANOVA SOURCE df SS MS EMS , (I/B/S) Between ? 9 Individuals N SS MS,, v£ + kv^ w w E w (Residual) Between measurements within 2 ind iv idua ls M SS^ MS£ v £ N = df for ind iv idua ls M = df fo r residual k = 2 2 v^= the di f ference between measurements within ind iv idua ls 2 M S w " M S E v^ = the di f ference between ind iv idua ls = ^ v estimates a l l the genetic variance and the environmental variance w 3 ar i s ing from permanent or non-local ised circumstances and which contributes to the variance between ind iv idua l s . Growth Performance Correlat ions Simple corre lat ions were calculated to determine i f there are any s i gn i f i can t re lat ionships between the average of several growth performance t r a i t s and the blood t r a i t leve ls of d i f fe rent breeds of c a t t l e . Do breeds with higher leve ls of a blood t r a i t exh ib i t higher or lower performance for a par t i cu la r growth t r a i t ? 27 The f i r s t step towards answering the ahove question was to scan the l i t e r a tu re fo r papers report ing the growth performance resu l ts of various ca t t l e breeds. Pr io r to der iv ing an average for each growth t r a i t of each breed i t was necessary to standardize the data drown from various sources. An indexing technique as described by Pr ingle (1973) was employed (Appendix I ) . Angus was assigned an index of 100 because th i s breed was common to many studies. The indices were weighted to account for unequal numbers of animals in each study and an average index for each growth t r a i t of each breed ca lcu la ted. Average indices were obtained from seven breeds for b i r th weight, weaning weight, f i na l weight, pre- and post-weaning average da i l y gain. Average indices for feed e f f i c i ency expressed as metabolizable energy and to ta l d iges t ib le nutr ients were also ava i lab le . Table 7 displays the average indices fo r each growth t r a i t by breed. The least squares constants of each blood t r a i t for each breed are l i s t e d in Table 7. Simple corre lat ions were calculated according to Steel and Torr ie (1960) and l i s t ed in Table 15. Mul t ip le Range Tests Duncan's mult ip le range tests were performed on the least squares constants of breed and stud as described by Steel and Torr ie (1960) with a minor modif icat ion to the ca lcu la t ion of the standard error of each treatment mean. The standard errors were calculated by the technique given by Harvey (1975). 28 The Effect of Groups of Related Animals on the Variance of Blood Tra i ts To test the hypothesis that a group of re lated animals would exh ib i t less var ia t ion in the i r blood t r a i t leve ls than a group of unrelated animals, the pedigrees of Holstein bu l l s from the Burl ington stud were compiled to two generations ( i . e . grandparents). The Holsteins were chosen because of the a v a i l a b i l i t y of ancestral information and because they comprised the largest group of bu l l s of the same breed from the same stud, thereby, e l iminat ing breed and stud e f fec ts . Inspection of the pedigrees revealed that at least 58 of the 60 Holste in bu l l s at Burl ington were re lated to at least one other animal in the stud. There were a set of twins, a number of hal f s ibs , and other re la t ionsh ips , such as, bu l l s being ha l f uncles to other bu l l s in the stud. More complex re lat ionships may be found upon further inspect ion. Twelve groups of paternal ha l f s ibs were selected for a least squares ana lys is . A break down of the groups fo l lows: #/Group # Groups 2 * 5 = 10 3 * 3 = 9 4 * 1 = 4 5 * 2 = 10 6 * 1 = 6 12 groups 39 Bul ls 29 The model f i t was: Y i j k = <> + G i + ^ ( i ) + b i t A ) 1 j k + e 1 j k where: y = the k th observation of the i th group and j th i nd i v idua l ; 1 J K a = the overa l l mean when A. i s equal to zero; G.j = the paternal h s ib group, i = 1, 2, 3 . . . 12; l j ( i ) = the j th indiv idual nested with in the i th group; b- = the regression of the dependent var iable Y.. . on the independent continuous var iable A . , each time holding the f i t t e d d iscrete var iab les , groups and ind iv idua ls constant; A . . . = the age in days at the time of sampling for the corresponding Y . . . ; and 1 J K e i j k = t h e r a n d o m e m 3 r > N I D (0» v 2 )» k = 1, 2. Individuals was the test ing term for groups. Groups was considered to be a f ixed e f fec t because of the res t r i c t i ons imposed by the inc lus ion of Holstein bu l l s from only one stud. I t was f e l t that the groups did not const i tute a random se lect ion of a l l possible Holstein ha l f s ib groups because the animals in the stud defined the groups ava i lab le for th i s study. Individuals with in groups was taken as a random ef fec t since the Hoi steins of each group were assumed to be a representative sample of a l l possible Holsteins of that group. When ind iv idua ls was i n s i gn i f i can t i t was pooled with the residual to become the test ing term for groups. 30 The Relatlons of Si,re BIood Composition to Progeny Test Results The progeny test resu l ts for 31 Holstein bu l l s were ava i lab le from the s i r e summaries produced by the Holstein Fr iesfan Associat ion of America (1977) (HFA) and the U.S. Department of Agr icu l ture (USDA) (Dickinson, 1978; Dickinson et a l . , 1975). The summaries provided daughter averages for pounds of mi lk, pounds of f a t , and percent f a t , plus the i r respective predicted d i f ferences. (Predicted differences are the expected average production of a b u l l ' s future daughters above or below breed average herdmates). The HFA summary did not include pounds of f a t , which therefore had to be calculated using the fol lowing formula: lbs FAT = % FAT * lbs MILK/100. Table 8 contains the progeny test resu l t s . A ser ies of stepwise mult ip le regressions were performed sett ing the blood t r a i t s and age of the s i re as the independent var iables with each progeny test var iable in turn as the dependent var iab le . 31 TABLE 1 BREAKDOWN OF ANIMALS BY BREED, STUD, AND SAMPLING BREED BURL P S P STUr WEST s ) CAL P S P MIL S P TOTAL S OVER ALL Maine Anjou 1 7 2 2 3 13 2 15 Simmental 2 8 9 2 1 5 1 17 11 28 Chianina 6 2 1 2 1 8 4 12 Charolais 1 3 3 3 1 7 4 11 Tarantaise 2 2 2 Angus 2 1 2 1 3 7 2 9 MEUSE-RHINE-YSSEL 2 1 2 2 4 3 7 Hereford 3 3 3 3 6 BlondeD'Aquitaine 1 6 3 2 8 4 12 Limousin 1 2 1 2 3 3 6 Pinzgaur 1 1 r 2 2 Gelbvieh 3 5 1 9 9 Brahman 4 2 4 2 6 Hays Converter 3 1 3 1 4 Brown Swiss 1 1 1 1 2 Romagnola 1 1 1 3 3 Short Horn 2 1 2 1 3 Marchiana 1 1 1 Beefalo 1 1 1 Beefmaster 1 1 1 Guernsey 6 6 6 Jersey 10 10 10 Holstein 62 5 7 1 2 2 42 73 48 121 186 91 277 P = Animals from which a second sample was received S = Animals from which only one sample was received BURL = Burl ington WEST = Western CAL = Calgary MIL = Milner 32 TABLE 2 BREAKDOWN OF ANIMALS AFTER SCREENING DATA BREED 1 BURLINGTON S T 2 WESTERN U D 3 MILNER 4 CALGARY BREED TOTALS 1. Maine Anjou 7 3 10 2. Simmental 2 6 5 2 15 3. Chianina 6 2 8 4. Charolais 3 3 6 5. Angus 2 3 5 6. Blonde D'Aquitaine 2 6 8 7. Gelbvieh 3 5 8 8. Guernsey 6 6 9. Jersey 10 10 10.Holstein 62 •7 2 71 STUD TOTALS 82 32 20 13 147 294 Samples (2 samples/animal) 33 TABLE 3 MODEL 1 EMS Source DF SS MS EMS Breed B-1 9 S S B MSB 2 2 6f + K 6 j + e I Stud S-l 3 s s s MSS 2 2 6 + K 67 + e I Individuals I 126 SSj MSj 2 2 e I Age 1 S S A MSA 6g+ X (A) Residual 154 N-B-S-I S S R MSR TOTAL N - l 2 9 3 ss T BKA TABLE 4 MODEL 2 EMS Source DF SS MS Breed B-1 9 ss B MSB Stud S-l 3 ss s MSS Age 1 S S A M S A 280 Residual N-B-S S S R MSR 293 TOTAL N-l ss T EMS *e + S 0 B 6" + B0Q e >^ 6^ + X ( A ) TABLE 5 COEFFICIENT OF DETERMINATION^2) FOR MODEL 1 BLOOD TRAIT BREED STUD . R^ I/B/S AGE RESIDUAL TOTAL Calcium 0.0542 0.0317* 0.4383 0.0204* 0.5034 0.4965 Phosphorus 0.0482 0.0059 0.5090* 0.0065* 0.2506 0.7494 Glucose 0.0467* 0.1023* 0.2827 0.0076* 0.2969 0.7031 Urea-N 0.0582* 0.1244* 0.2921* 0.0011 0.1208 0.8791 Uric Acid 0.0398 0.1871* 0.3495* 0.0061 0.2864 0.7136 Cholesterol 0.0567* 0.0193 0.3979 0.0128 0.5044 0.4955 Total Protein 0.0300 0.0039 0.4688* 0.0041 0.2961 0.7038 Albumin 0.0634 0.0158 0.5875* 0.0001 0.3328 0.6671 B i l i r ub i n 0.0365 0.0468* 0.2771 0.0022 0.5770 0.4230 ALKP 0.0314 0.0073 0.4854* 0.0315* 0.1264 0.8736 LDH 0.1636* 0.0231 0.3822 0.0193* 0.4234 0.5766 SGOT 0.1063* 0.0384* 0.4663* 0.0055* 0.2096 0.7903 Sodium 0.0184 0.0078 0.4457 0.0001 0.5113 0.4886 Potassium 0.0459 0.0330* 0.4045 0.0090 0.4618 0.5381 * S ign i f i cant at P<0.05 TABLE 6 COEFFICIENTS OF DETERMINATION (R 2) FOR MODEL 2. R2 BLUUU TRAIT BREED STUD AGE RESIDUAL TOTAL Calcium 0.0401 0.0165 0.0030 0.9418 0.0582 Glucose 0.0476* 0.1062* 0.0271* 0.5796 0.4203 Cholesterol 0.0539 0.0256* 0.0190* 0.9023 0.0976 B i l i r ub i n 0.0433 0.0755* 0.0351* 0.8541 0.1458 LDH 0.1531* 0.0449* 0.0070 0.8056 0.1943 Sodium 0.0175 0.0082 0.0034 0.9571 0.0429 Potassium 0.0430 0.0273* 0.0051 0.8663 0.1336 •S ign i f i cant at P< 0.05 TABLE 7 BREED LEAST SQUARES CONSTANTS OF BLOOD TRAITS AND GROWTH TRAIT INDICES BREED 1 2 3 4 5 6 7 99 89 88 90 89 93 92 Ca 68 63 6 7 66 74 66 64 P 66 60 61 57 69 67 62 GLUCOSE 13 14 17 14 19 16 13 urea-N 15 13 13 13 13 13 14 URIC 143 125 119 117 126 107 116 CHOL 79 75 73 76 76 74 76 TPROT 3 8 36 3 6 36 36 37 36 ALB 3 3 3 3 3 3 2 BILI 100 63 75 79 73 78 66 ALKP 1155 1209 1034 9 7 0 1124 856 1066 LDH 115 117 122 116 120 125 116 SGOT 141 140 140 140 141 139 140 Na 45 42 44 43 42 43 44 K 100 126 1 2 3 131 133 118 74 BIRTH WT 100 143 133 129 123 124 84 WEANING WT 100 134 128 115 110 117 84 FINAL WT 100 106 104 106 115 111 86 PRE-WEAN ADG 100 112 113 115 115 110 82 POST-WEAN ADG 100 90 90 99 102 102 103 TDN 100 90 90 9 9 102 102 103 ME BREEDS 1. Angus 2. Charo la is 3. Simmental 4. Maine Anjou 5. Chi anina 6. Gelbvieh 7. Jersey 37 TABLE 8 HOLSTEIN PROGENY TESTS RESULTS DAUGHTER AVERAGES SIRE ID(a) MILK(b) % FAT FAT(b) PD MILK(c) PD % FAT PD FAT 2102 16049 3.86 619 -397 15 6 2047 16867 3.61 608 270 -1 8 2050 15314 3.63 555 -660 -2 -27 2036 16258 3.77 612 -450 11 -1 2038 17364 3.58 621 482 -4 11 2028 17181 3.59 616 335 -2 10 2142 17259 3.61 623 620 -2 20 2037 17374 3.57 , 620 467 -2 14 2136 17510 3.66 640 417 3 19 2039 16034 3.58 574 76 -2 0 2143 16150 3.46 558 174 -9 -7 2100 17034 3.53 601 180 -10 -8 2025 17550 3.60 631 421 5 22 2042 18947 3.50 663 1003 -4 31 2133 17299 3.56 615 20 4 7 2105 17374 3.53 613 488 -9 4 2032 16197 3.60 583 -588 2 -18 2048 15566 3.58 557 -626 -5 -29 2134 16214 3.63 588 97 -3 -1 2104 17113 3.63 621 238 -6 0 2135 16152 3.60 581 -18 2 2 2168 15518 3.60 565 63 -11 -14 38 TABLE 8 - CONTINUED DAUGHTER AVERAGES SIRE ID(a) MILK(b) % FAT FAT(b) PD MILK(c) PD % FAT PD FAT 2111 17489 3.60 636 898 -4 26 2163 16619 3.70 616 192 0 7 2138 17802 3.50 623 272 -4 4 2178 16078 3.90 630 437 8 28 2139 16635 3.60 607 390 -3 10 2162 17319 3.80 658 726 8 38 2144 18332 3.60 660 357 -3 9 2153 15942 3.70 585 81 -2 0 2164 18935 3.60 680 1406 -9 37 (a) ID # GIVEN BULL BY STUD (b) POUNDS (c) PREDICTED DIFFERENCE References: 1. Dickinson (1978) 2. Dickinson et a l . (.1975) 3. Holstein Fr ies ian Associat ion of America (1977) 39 TABLE 9 RANGES AND MEANS FOR AGE AND THE BLOOD TRAITS RANGE ARITHMETIC MEAN ± SD LEAST SQUARE MEAN ± SE AGE (Days) 299 4407 1418± 678 CALCIUM mg/dl 4.9 10.9 9.1± 0.9 9.2 ±0.05 PHOSPHORUS mgP/dl 4.3 9.8 6.6± 0.9 6.7 ±0.05 GLUCOSE mg/dl 35 110 69± 12 64 ±0.70 UREA-N mg/dl 6 43 14± 5 15 ±0.29 URIC ACID mg/dl 0.7 2.1 1.2± 0.3 1.3 ±0.03 CHOLESTEROL mg/dl 53 236 120± 27 120 ±1.6 T. PROTEIN gm/dl 3.8 9.2 7.4± 0.8 7.5 ±0.05 ALBUMIN gm/dl 2.7 4.2 3.6± 0.3 3.6 ±0.02 BILIRUBIN mg/dl 0.1 0.5 0.3± 0.08 0.3 ±0.005 ALKP U/l 27 262 77± 40 79 ±2.3 LDH U/l 280 1660 943± 245 1008 ±14 SGOT U/l 69 237 113± 24 117 ±1.4 SODIUM meq/1 121 151 140± 4 140 ±0.23 POTASSIUM meq/1 3.4 6.3 4.3± 0.3 4.4 ±0.02 U/l = Micromoles per L i t re dl = Decal i t re = 100 ml SD = Standard Deviation SE = Standard Error of Mean n = 294 TABLE 10 REFERENCE 1 Ca P1 GLU1 UREA-N URIC1 CH0L1 T.PROT 2 ALB 2 BI L l 1 Na 3 K 3 Arthaud et al.(1969) 72.0 Bol ing et al .(1972) 17.2 8.41 Diven et al .(1958) 27.1 2.50 80 7.20 Ga lbra i th & Watson (1978) 85.4 29.5 7.20 3.54 Ga lbra i th et al.(1978) 88.5 16.9 6.41 3.56 Heuschele & Barber (1966) 15.0 6.82 4.50 .342 4.74 MacDonald et al.(1956) 64.0 14.3 1.92 Manston et al.(1977) 9.98 9.03 63.0 12.0 2.82 138 5.58 Reid et al . (1948 a) 11.52 7.34 6.90 4.02 Rowlands et al.(1977) 10.50 8.00 3.26 138 5.37 Rusoff et al.(1954) 10.31 4.64 Stark et al.(1978) 9.60 6.20 48.1 2.91 139 5.95 Taylor et al.(1966) 120 Wilson and Dinkel (1968a) 6.59 1. mg/100 ml 2. g/100 ml 3. meq/1iter o 41 TABLE 11 BLOOD TRAIT LEVELS FROM LITERATURE FOR COWS R E F E R E N C E 1 2 3 4 5 Ca(mg/100ml) 9.15 9.6 9.59 9.54 9.90 P (mg/1OOml) 5.8 5.59 4.88 5.75 Glucose(mg/100ml) 42.5 65.6 54.1 Urea-N (mg/1OOml) 17.8 16.1 14.1 16.1 Uric Acid(mg/100ml) 1.06 1.07 0.91 Cholesterol(mg/1OOml) 143 195 206 195 T. Protein(g/100ml) 7.37 8.24 7.62 7.41 Albumin(g/100ml) 3.63 3.4 4.00 3.66 2.12 Bilirubin(mg/100ml) .170 ALKP (p/£) 35.0 40.7 72.9 LDH(yA) 733 SGOT(y/£) 127 136 86 Sodium(meq/£) 140 137 141 Potassium(meq/)i) 5.0 4.24 1. Ross and Hal l iday (1976) 2. Payne et al .(1974) 3. Peterson and Waldern (1981) 4. Nash (1978) 5. Basuthakur (1973) TABLE 12 AGE REGRESSION COEFFICIENTS AND REPEATABILITYS REGRESSION SE REPEATABI Calcium -0.00008 0.00009 0.0310 Phosphorus -0.00036 0.00018 0.4257 Glucose -0.00332 0.00092 0.0758 Urea-N 0.00089 0.00075 'o.4943 Uric Acid -0.00011 0.00006 0.1973 Cholesterol -0.00630 0.00260 0.0000 Total Protein 0.00025 0.00017 0.3185 Albumin 0.00001 0.00006 0.3661 B i l i r u b i n 0.00003 0.00001 0.0000 ALKP -0.03520 0.00568 0.6488 LDH -0.03443 0.02199 0.0491 SGOT 0.00864 0.00431 0.4622 Sodium -0.00035 0.00035 0.0316 Potassium -0.00004 0.00003 0.0340 43 TABLE 13 REPEATABILITYS FROM THE LITERATURE {%) 1 2 3 4 5 6 Calcium 38 13 20 35 3 12 Phosphorus 51 17 28 42 43 20 Glucose 50 14 35 32 8 14 Urea-N 35 23 12 25 49 30 Uric Acid 20 19 Cholesterol 0 20 Total Protein 43 32 26 Albumin 67 33 52 68 37 36 B i l i r u b i n 0 ALKP 65 74 LDH 5 34 SGOT 46 22 Sodium 23 11 2 2 3 Potassium 47 29 31 21 3 1. Rowlands et al-(1974a) 2. Kitchenham and Rowlands (1976) 3. Kitchenham et al .(1977) 4. Stark et al TTW8J 5. The resul ts of th i s study 6. Peterson and Waldern (1981) 44 TABLE 14 CORRELATIONS BETWEEN ALL CONTINUOUS VARIABLES AGE CALCIUM PHOSPHORUS GLUCOSE UREA-N. Age 1.0000 Calcium 0.0030 1.0000 Phosphorus -0.3956 0.1185 1.0000 Glucose -0.2826 0.2268 0.2101 1.0000 Urea-N 0.3449 0.0231 0.0504 -0.2966 1.0000 Uric Acid 0.0843 -0.0499 0.0709 -0.2539 0.4842 Cholesterol -0.1462 -0.0105 0.0274 -0.0425 0.0876 T. Protein 0.4496 0.6322 -0.1420 -0.0245 0.1571 Albumin 0.0287 0.5736 -0.0467 -0.0092 -0.0218 B i l i r u b i n 0.0552 -0.0251 -0.2042 0.1480 -0.0326 ALKP -0.5761 0.0900 0.4320 0.1935 -0.1813 LDH -0.0239 0.1577 0.0650 -0.1232 0.0506 SGOT 0.2816 0.1818 0.0367 -0.1268 0.4593 Sodium 0.1064 0.5640 0.1409 0.0634 0.0557 Potassium -0.0464 0.1405 0.2182 -0.1634 -0.0089 45 TABLE 14 CORRELATIONS CONTINUED URIC ACID CHOLESTEROL T.PROTEIN ALBUMIN BILIRUBIN AGE Calcium Phosphorus Glucose Urea-N Uric Acid 1.0000 Cholesterol 0.2914 1.0000 T. Protein -0.0542 -0.1460 1.0000 Albumin 0.0179 0.0994 0.5152 1.0000 B i l i r u b i n 0.3030 0.2790 0.0451 0.1834 1.0000 ALKP 0.0187 0.1655 -0.3251 -0.0861 -0.0597 LDH 0.0834 0.0618 0.1348 0.1882 -0.2537 SGOT 0.3585 0.1124 0.3262 0.1169 -0.1076 Sodium 0.0072 0.0089 0.4498 0.4076 -0.0994 Potassium 0.2005 0.0023 0.0011 0.1427 -0.0684 46 TABLE 14 CORRELATIONS CONTINUED ALKP AGE Calcium Phosphorus Glucose Urea-N Uric ACid Cholesterol T. Protein Albumin B i l i r u b i n ALKP LDH SGOT Sodium Potassium 1.0000 0.0316 -0.1439 -0.0474 0.1305 LDH 1.0000 0.3411 0.2552 0.1310 SGOT SODIUM SIGNIFICANCE LEVELS I rO.05(2),2^2 = 0.113 rO.01(2),292 = 0.148 1.0000 0.1865 0.0111 1.0000 0.3282 POTASSIUM 1.0000 TABLE 15 GROWTH TRAIT - BLOOD PROFILE CORRELATIONS B-WT W-WT F-WT PREADG POSADG TDN ME B-WT 1.0000 W-WT 0.9056 1.0000 F-WT 0.8073 0.9721 1.0000 PREADG 0.9090 0.7499 0.6547 1.0000 POSADG 0.9907 0.9082 0.8323 0.9124 1.000 TDN -0.4022 -0.6837 -0.7962 -0.1275 -0.4301 1.0000 ME -0.4022 -0.6837 -0.7962 -0.1275 -0.4301 1.0000 1.000 C3 -.0.5279 -0.6187 -0.5409 -0.3037 -0.4616 0.4702 0.4702 P 0.3768 0.0078 -0.1034 0.5513 0.3583 0.3476 0.3476 GLU -0.0532 -0.2631 -0.2682 0.3422 -0.0345 - 0.5168 0.5168 UREA-N 0.6120 0.4415 0.3639 0.7198* 0.5994 -0.0392 -0.0392 URIC -0.7116* -0.7713* -0.6752 -0.5927 -0.6704 0.3388 0.3388 CHOL -0.0791 -0.1941 -0.1435 -0.0653 -0.0654 -0.0973 -0.0973 T.PROT -0.3565 -0.5656 -0.5942 -0.2640 -0.3697 0.4671 0.4671 ALB -0.2706 -0.3560 -0.2604 -0.0228 -0.1783 0.3011 0.3011 BILI -0.8554* 0.7657* 0.7477* 0.8542* 0.9043* -0.3918 -0.3918 ALKP -0.0662 -0.2751 -0.2354 0.0671 0.0202 0.2685 0.2685 LDH -0.0752 -0.0317 0.0115 -0.1642 -0.1212 -0.3503 -0.3503 SGOT 0.3659 0.3940 0.4142 0.5436 0.4170 -0.0477 -0.0477 Na -0.0000 -0.2418 -0.2805 -0.0000 -0.0344 0.0858 0.0858 K -0.6520 -0.6450 -0.5079 -0.6287 -0.5646 0.1331 0.1331 * S ign i f i cant at P<0.05 48 RESULTS AND DISCUSSION Ranges and Means Table 9 displays the ranges and means of the blood t r a i t s measured in th i s study. Tables 10 and 11 convey the blood t r a i t means reported in the l i t e r a t u r e . Table 10 has the resu l ts of studies on bu l l s and steers; Table 11 the resu l ts of cows. Comparing the two tables (10 and 11) one can see that male and female ca t t l e have a s im i la r blood leve ls for calcium, phosphorus, glucose, urea-N, tota l prote in , albumin, sodium, and potassium. The bu l l s have a wider range of means for phosphorus and glucose. The mean of 9.2 mg/dl for calcium in th i s study i s in agreement with that reported by Ross and Hal l iday (1976) in the i r study of 200,000 ca t t l e in Scotland but i s lower than the means of the other papers. The mean for phosphorus i s higher than the cow means but with in the range of the bul l and steers means. Glucose, urea-N, tota l p ro te in , albumin, sodium, andpotassium are wi th in the ranges of the means for cows and bu l l s . The bul l means for ur i c acid (2.50, 1.92 mg/dl) are higher than the means given for cows (1.06, 1.07, 0.91 mg/dl). The ur ic acid mean of th i s study (1.3 mg/dl) f a l l s between the two sets of means. The higher leve ls of ur i c acid reported by Diven et a l . (1958) and McDonald et a l . (1956) are based on blood samples from f i ve year l ing Hereford steers and eighteen Hereford and Angus 800 lb male ca lves, respect ive ly . Their resu l ts may not be representative of bu l l s in general and adult animals in pa r t i cu l a r . Ur ic acid may be lower in older animals. The ef fect of age on ur i c acid in bu l ls has not been reported in the l i t e r a t u r e . 49 There was no s i gn i f i c an t age e f fec t for u r i c acid in th i s study. This study's cholesterol mean agrees with that of Taylor et a l . (1966) for Hereford bu l l s . The cholesterol means of the cow reports are higher than the means reported by Diven et al.(1958) and Taylor et a l . (1966) for bu l l s but the resu l ts of Taylor et al.(1966) based on 86 Hereford bu l l s (710 days old) and th i s study are f a i r l y close to those of Ross and Hal l iday (1976). A possible explanation for the higher leve ls of cholesterol in da i ry cows could be the i r energy intake. Stufflebeam et al.(1969) found a pos i t i ve re la t ionsh ip between cholesterol in beef hei fers and the i r energy intake. Serum cholesterol leve ls increased with a higher energy intake. Stufflebeam and Lasley (1969) reported a s im i la r re la t ionsh ip between cholesterol and energy intake in Hereford cows and bu l l s . Dairy cows fed for milk production may well have a higher energy intake than bu l l s in a stud which would resu l t in a higher cholesterol l e v e l . This study's mean of 0.3 mg/dl i s s im i la r to the mean of 0.342 found by Heuschele and Barber (1966) in Hereford steers for b i l i r u b i n but higher than the 0.170 mg/dl reported by Nash (1978) for dairy c a t t l e . The mean of SGOT from th i s study i s with in the range of means given for cows by Peterson and Waldern (1981), Nash (1978), and Basuthakur (1973). The a lka l ine phosphatase mean i s s im i l a r to that of Basuthakur (1973) and higher than those of Peterson and Waldern (1981) and Nash (1978). The l a c t i c dehydrogenase mean of th i s study i s higher than the mean of Peterson and Waldern (1981). 50 Temperament Temperament was excluded from the model used in th i s study because i t was i n s i gn i f i c an t fo r a l l the blood " t ra i t s . I t accounted for less than one percent of the tota l var ia t ion of any one blood t r a i t . Palmer et a l . (1930) reported a s i gn i f i c an t handling stress e f fec t for phosphorus in dairy cows. Phosphorus leve ls increased af ter vigorous exercise followed by a marked decrease af ter hal f an hour to a point below the leve l p r io r to the exercise and remained low for at least two hours. Gartner et a l . (1969) was unable to f ind any consistent e f fec t of exc i ta t ion and exercise on the level of phosphorus in fo r ty Austra l ian I l lawara shorthorn year l ing ca t t l e . The changes in tota l protein were small but s i gn i f i c an t . Potassium was not af fected. The resu l ts of th i s study are not surpr is ing because the majority of the animals were quite calm when b led, espec ia l ly those bled from the t a i l . Neck bleeding required ty ing the b u l l ' s head o f f to one side whch tended to cause more stress in the animal. Another factor which contributed to the calmness of the animals was that they were accustomed to handling by humans, in par t i cu la r the s ta f f at the studs which aided in the bleeding. A l so , the assigning of a temperament rat ing to an animal was dependent on the judgement of the recorder. I t was not always c lear as to what rat ing an animal deserved. There were no def in i te boundaries between the categories: calm, moderately exc i ted, and very exc i ted, Inconsistencies would have occurred between the d i f fe rent 51 studs. An animal's behaviour was judged re l a t i ve to the behaviour of the other animals in the stud sampled before him and to the experience of the recorder. Stud The ef fect of stud on the blood t r a i t s w i l l have included the environmental influences re la t ing to the ind iv idual feeding and management programs of the stud. Also included are environmental factors pecul iar to each stud. Stud was s i gn i f i can t for glucose, urea-N, ur ic ac id , cho les tero l , b i l i r u b i n , l a c t i c dehydrogenase, SGOT and potassium. I t accounted for 10, 12, and 19% of tota l var ia t ion in glucose, urea-N, and ur ic ac id , respect ive ly , but less than 8% in the remaining blood t r a i t s (Table 5 and 6) . The s i t e of blood withdrawal on the animal was confounded within stud e f fec t s . The veter inar ians at Burl ington and Milner bled the bu l l s from the neck while at Western and Calgary bu l l s were bled from the t a i l . Parker and Blowey (1974) and Teleni et a l . (1976) both reported s i gn i f i c an t di f ferences between phosphorus leve ls of the jugular vein and the coccygeal artery and ve in. Phosphorus was considerably higher in the coccygeal vessels (12%, Teleni et a l . , 1976) than the jugular ve in. Parker and Blowey (1974) at t r ibuted the resu l ts to sa l i va production withdrawing phosphorus from the a r t e r i a l blood of the head. Teleni et al.(1976) had s im i la r conclusions and recommended t a i l sampling when test ing for phosphorus. Phosphorus was not s i gn i f i c an t 52 for stud ef fects in th i s study. Other environmental ef fects may have overshadowed the sampling e f fec t . Factors perta in ing to feed and management were not measured for th i s study and therefore w i l l not be included in th i s d iscuss ion. Stud was included in the analysis as a source of variance to be accounted for and removed from the tota l variance of a blood t r a i t . Individuals The s t a t i s t i c a l model was e f f i c i e n t for a l l the blood t r a i t s . The coef f i c ien ts of determination for the model are displayed in Table 5. The port ion of the overa l l var ia t ion of the blood t r a i t s at t r ibuted to the f i t t e d ef fects ranged from 0.42 to 0.87. The var ia t ion between ind iv idua ls received the largest share of th i s part i t ioned var ia t ion for each blood t r a i t (0.27 to 0.58). The other ef fects general ly had much smaller contr ibut ions (< 0.10); the exceptions being 0.16 and 0.11 for the breed ef fects of l a c t i c dehydrogenase and SGOT, and the stud ef fects of glucose, urea-N, and ur ic acid (0.10, 0.12, and 0.19, respect ive ly ) . The residual var ia t ion which in th i s study was the var ia t ion between repeated samples from an ind iv idual was also an important source of v a r i a b i l i t y in the leve ls of the blood t r a i t s (0.12 to 0.57). Between ind iv idua ls var ia t ion was s i gn i f i c an t l y greater than the within ind iv idua ls var ia t ion for seven of the fourteen blood t r a i t s . These were phosphorus, urea-N, ur ic ac id , tota l prote in , 53 albumin, a l ka l ine phosphatase, and SGOT. The resu l ts indicate a de f in i te i nd i v i dua l i t y among bu l l s in the i r blood p ro f i l e s . This conclusion i s supported by the f indings of other researchers. Stark et a l . (1978) found s i gn i f i can t differences between indiv idual Fr ies ian bu l l s for glucose, urea-N, albumin, phosphorus, calcium, and potassium. Sodium was not s i gn i f i c an t . Kitchenham et a1.(1977) reported s im i la r resu l ts for albumin and sodium in a study with bu l l s and steers. Kitchenham and Rowlands (1976) and Rowlands et a l . (1975) concluded that dairy cows have indiv idual patterns of blood chemistry which may change with age. Individual cow p ro f i l e s were d i f fe rent for glucose, calcium, potassium, sodium, phosphorus, urea-N, albumin, and tota l prote in. Rowlands et a l . (1974 a)reported indiv idual blood p ro f i l e s in calves for glucose, urea-N, albumin, phosphorus, calcium, sodium, and potassium. Crookshank et a l . (1952), Russoff et a l . (1954), and A l l c r o f t and Fol ley (1941) reported that a lka l ine phosphatase leve ls varied ..widely between animals but remained r e l a t i v e l y constant within animals. A lka l ine phosphatase had a high repeatab i l i t y (0.65) in th i s study which indicates a much larger between ind iv idua ls variance than with in ind iv idua ls variance. The with in ind iv idua l component i s en t i r e l y environmental in o r ig in caused by temporary differences in environmental condit ions between successive samples. The between indiv idual component i s par t ly environmental and part ly genetic, the environmental part being caused by circumstances that af fect the animal permanently (Falconer, 1960). This between ind iv idua ls component i s expressed as a proportion of the variance of s ingle measurements (within ind iv idua ls 54 variance) by the repeatab i l i t y calculated for each blood t r a i t (Table 12). The repea tab i l i t i e s ranged from 0 to 65%. The zero repeata-bi 1 i t i e s of cholesterol and b i l i r u b i n indicate a neg l ig ib le input of genetic and permanent environmental fac tors . Other blood t r a i t s with a small genetic input were calc ium, glucose, l a c t i c dehydrogenase, sodium and potassium. These blood t r a i t s are very susceptable to temporary environmental inf luences. These temporary environmental inf luences might include such factors as handling s t ress , d iu rna l , seasonal and monthly va r i a t i on , semen co l l e c t i on , sample storage, water intake, and the proximity of feeding and sampling time. Handling stress (temperament) was not an important contr ibut ion to wi th in ind iv idua ls var ia t ion in th i s study. Handling stress has already been discussed in the temperament sect ion. The work done by Spate et a l . (1970) indicated that the time spent in storage by the blood samples pr ior to analys is affected the leve ls of the blood t r a i t s . Spate et a l . (1970) were unable to f ind changes in the concentrations of cho les te ro l , b i l i r u b i n , glucose, tota l p ro te in , urea-N, sodium, and potassium brought about by storage at -10°C for a month. Calcium and phosphorus increased sharply a f ter ten days at -10°C. The enzymes, a lka l ine phosphatase, l a c t i c dehydrogenase, and SGOT, were the least s tab le . Spate et a l . (1970) found that within theone month l im i t of the i r study SGOT tended to decrease then 55 gradually increase. Lact ic dehydrogenase increased then remained stable theraf ter . A lka l ine phosphatase increased for a few days then gradually decreased. Spate et al.(1970) recommended that enzyme assays should be completed as soon as possible a f ter co l l e c t i on . Sampling occurred over a three month period in th is study which necessitated var iab le storage times of well over the one month time period looked at by Spate et a l . (1970). Spate et a l . (1970) found the enzymes unstable in storage but in th i s study the enzymes SGOT and a l ka l i ne phosphatase had repea tab i l i t i e s of 0.46 and 0.65, respect ive ly which indicate that some sort of equi l ibr ium state i s attained af ter a month in storage. This hypothesis i s supported by the resu l ts of l a c t i c dehydrogenase which increased then remained stable (Spate et a l . 1970). Phosphorus which exhibited a sharp increase af ter ten days at -10°C also had a high repeatab i l i t y (0.43) in the present study. Even i f some state of equi l ibr ium was reached i t i s important to know i f the process by which the equi l ibr ium came about has a l tered the re lat ionsh ips of the blood t r a i t s between samples of an i nd i v i dua l , eg . , i f phosphorus concentrations have increased to an equi l ibr ium point has the process affected both samples of an ind iv idua l equal ly such that di f ferences between the samples for phosphorus are proport ionately the same as at the time of sampling. I f not, then the with in ind iv idua ls variance w i l l be a l tered for that blood t r a i t . The same question appl ies to samples from d i f fe rent ind iv idua l s . I f the process i s not consistent for a l l ind iv idua ls then the variance between ind iv idua ls for a blood 56 t r a i t w i l l be affected by storage time. I t seems un l i ke ly that the equi l ibr ium process w i l l proceed equal ly for a l l samples because the chemical reactions occurring in the serum which a f fec t the blood t r a i t leve ls measured by the present study w i l l be fueled by substances, themselves which are in var iable amounts in each sample. These reactions w i l l proceed for varying lengths of time and at varying rates to eventual ly stop af ter increasing or decreasing the blood t r a i t leve ls by var iable amounts for each sample. I t seems quite reasonable to assume that time spent in storage w i l l have contributed to the sample variance of several blood t r a i t s . The importance of th i s contr ibut ion could vary among the blood t r a i t s which Spate et a l . (1970) reported to be affected by storage. The repea tab i l i t i e s of phosphorus, SGOT, and a lka l ine phosphatase suggest i t may not be as important an inf luence to the sample variance for these blood t r a i t s as i t i s for calcium and l a c t i c dehydrogenase which have very low r epea tab i l i t i e s . I f time spent in storage brings about an i n f l a t i on or def la t ion in e i ther the between or with in ind iv idual variances i t could have affected the resu l ts of th i s study. The i n f l a t i on of ind iv idual variances would make i t less l i k e l y for the other ef fects to appear s i gn i f i can t in the analys is of variance. The def la t ion of the variance could have ef fects appearing s i gn i f i can t when they should not be. An in terest ing study of th i s problem would be one where the blood t r a i t s are measured short ly a f ter samples are drawn from the animals and analysed again af ter a few months in frozen storage. 57 I t would be useful not only as a check on how the blood t r a i t leve ls have al tered but also as to what e f fec t these changes would have had on the resu l ts and conclusions of a study such as t h i s . Would the resu l ts for the main ef fects and the covariable be the same for both sets of data? I f not, then storage time of blood samples i s an important e f fect external to the study proper which must be considered in the planning of experiments, otherwise, the resu l ts are a re f l e c t i on of the handling procedure of the samples rather than the actual experiment i t s e f . Water intake and water deprivat ion seem un l i ke ly causes of var ia t ion in th i s study since the bu l l s would have had free access to water in the i r s t a l l s . None of the animals were subjected to physical stress pr io r to bleeding such that would induce substantial intake of water. Even though the feeding programs of the studs were confounded with stud e f f ec t s , nu t r i t i on w i l l have contributed to ind iv idua l va r i a t i on . Each animal on a par t i cu la r feeding program w i l l not have responded in exact ly the same manner as his companions. Feed intake w i l l have varied from animal to animal. They w i l l not a l l grow and mature at the same rate. It i s to be expected that those blood t r a i t s susceptible to nut r i t i ona l inf luences w i l l have had some contr ibut ion to the between ind iv idua l var ia t ion by the feeding program of the animal. Numerous papers discuss the ef fects of nu t r i t i on on the blood t r a i t s . The l i t e r a tu re review gives the resu l ts of a number of these. 58 The proximity of feeding and sampling also inf luences the leve ls of the blood t r a i t s . Kennedy et al.(1939) and Coggins and F ie ld (1976) reported an increase in glucose leve ls a f ter feeding. Coggins and F ie ld (1976) also noted an increase in urea-N. Palmer et a l . (1930) found a small but s i gn i f i can t increase in phosphorus. This factor w i l l have contributed to the with in ind iv idua ls variance because the second sample drawn from an animal w i l l not have been taken at a time post-feeding ident ica l to the f i r s t sample. The blood t r a i t leve ls which change a f te r feeding w i l l have been at d i f fe rent stages of the i r post-feeding cycles for the f i r s t and second samplings. Coggins and F ie ld (1976) associated most of the s i gn i f i can t diurnal var ia t ion in glucose, urea-N, albumin, and calcium with feeding. This i s not surpr is ing since feeding which occurs at spec i f i c in terva ls during the day w i l l cause a regular pattern of changes in the blood t r a i t s which i t a f fec t s . Seasonal var ia t ion was not l i k e l y to have been of much consequence in th i s study because blood sampling occurred during the spr ing. The l i t e r a tu re indicates that a seasonal e f fec t would be relevant i f a winter - summer program of sampling had been used. Russoff et al.(1954) detected s i gn i f i c an t monthly var ia t ion in calcium and a lka l ine phosphatase. Monthly var ia t ion i f present within th i s study would have contributed to with in ind iv idual va r i a t i on . Reid et a l . (1947) and Reid et al.(1948 b)found semen co l l ec t i on to exert a strong inf luence on the plasma leve ls of a lka l ine phosphatase 59 in bu l l s . They concluded that the quantity or frequency of semen ejaculates, more pa r t i cu l a r i t y the number of spermotozoa, produced by the bulls.was the major factor in determining the level of a lka l ine phosphatase in the blood plasma. Semen co l l ec t i on w i l l have contributed to the between ind iv idua ls variance because bu l l s wi11 not have been on ident i ca l co l l e c t i on programs. A lka l ine phosphatase has a high repeatab i l i t y (0.65) which indicates a large between ind iv idua ls variance. Semen co l l e c t i on could well be an important factor inf luencing the repeatab i l i t y of a l ka l ine phosphatase through the permanent environment component of the between ind iv idua ls var iance. Blood sampling occurred over a r e l a t i v e l y short period of time. The second sample was taken about a month af ter the f i r s t during which time the semen co l l e c t i on program of a bul l was un l i ke ly to have a l te red . As such i t would appear as a permanent environmental e f fec t in th i s study because i t would have kept the leve ls of a lka l ine phosphatase r e l a t i v e l y constant between repeated samples. The environmental factors mentioned above are no doubt but a few of the many forces which operate both i n te rna l l y and externa l ly to af fect in some way the blood p ro f i l e of an animal. The repea tab i l i t i e s of phosphorus, urea-N, ur ic ac id , to ta l prote in , albumin, a lka l ine phosphatase, and SGOT indicate the po s s i b i l i t y of some genetic input (Table 12). Ur ic acid has a repea tab i l i t y of 0.20. The others range from 0.32 up to 0.65. Table 13 displays the repea tab i l i t i e s of th i s study and those of other researchers reported in the l i t e r a t u r e . The repea tab i l i t i e s from the l i t e r a tu re are from studies involv ing young calves (Rowlands et a l . , 1974 a),cows (Kitchenham and Rowlands, 1976), and bu l l s and steers (Stark e t a l . , 1978; Kitchenham et a l . , 1977). There i s a f a i r l y 60 broad range of repeatabil i.ti.es for each blood t r a i t which most l i k e l y re-f l e c t the d i f fe rent environmental influences act ing with in each study. The permanent and temporary environmental factors which contr ibute, respect ive ly , to the between and within ind iv idua ls variances w i l l not a l l be the same nor of the same importance in the d i f fe rent types of animals; i e . b u l l s , cows, ca lves. In cows lac ta t ion and pregnancy inf luence the blood p ro f i l e while in young calves growth and development are important fac tors . Factors pecul iar to each study w i l l also con t r i -bute to d i f fe rent repea tab i l i t i e s occurring in d i f fe rent studies on the same type of animal. * Peterson and Waldern (1981) reported that cows in d i f fe rent physio logica l stages have d i f fe rent repea tab i l i t i e s for the i r blood t r a i t s . The physio logica l stages were lac ta t ing non-pregnant, lactat ing-pregnant, and dry. They suggested that genetic differences may be masked in part by phys io logica l e f fec t s . This could be a par t i a l explanation for the d i f fe rent repea tab i l i t i e s reported for cows, ca lves, and bu l l s . These animals f a l l into d i f fe rent physio logica l groupings. Unfortunately the variance between ind iv idua ls cannot be part i t ioned into the variance caused by permanent or general environ-mental ef fects and that caused by genotype. The high repeatab i l i t y of a lka l ine phosphatase (0.65) may large ly be a resu l t of semen co l l e c t i on . The repea tab i l i t i e s set the upper l im i t s of the h e r i t a b i l i t i e s of the blood t r a i t s . They are useful in that they indicate d i rect ions in which further research may prove promising. 61 The i nd i v i dua l i t y of the blood t r a i t s and the blood p ro f i l e of an animal could prove useful in the se lect ion of breeding stock i f any strong re lat ionsh ips between the blood p ro f i l e and the t r a i t s of economic importance in the l ivestock industry can be detected. I t was with th i s in mind that three addit ional studies were under-taken with the l im i ted amount of data that could be gathered from various sources. Daughter production and bul l pedigree information were ava i lab le on a number of the Holste in bu l l s from the Burl ington stud. The corre lat ions with the growth t r a i t s are included in the breed d iscuss ion. The pedigree information allowed an invest igat ion into whether groups of re lated animals (ha l f s ibs) would exh ib i t less var ia t ion in the i r blood t r a i t s leve ls than a group of unrelated animals. I f a blood t r a i t i s under genetic control re lated animals should have blood t r a i t leve ls grouping c loser together than would be found in unrelated animals. The resul ts of other researchers lend support to th i s hypothesis. Ageraard and Katholm (1978) and Ageraard (1978) found s i gn i f i c an t l y less var ia t ion in a lka l ine phosphatase a c t i v i t y in calves within hal f s ib groups. Lane et a l . (1968) reported s i gn i f i c an t s i re ef fects in Guernsey cows for phosphorus, sodium, and potassium. Roubicek and Ray (1972) had s i gn i f i can t s i r e ef fects for albumin and tota l prote in . The l i t e r a tu re review contains the resu l ts of other relevant studies. This study was unable to detect any s i gn i f i can t s i re ef fects upon the blood t r a i t s of ha l f s ib groups of Holstein bu l l s from the Burl ington stud other than for b i l i r u b i n which was very close 62 to being i n s i gn i f i c an t . The variances between and within ha l f s ib groups may not have been s i gn i f i c an t l y d i f fe rent because of the many in te r - re la t ionsh ip between animals of d i f fe rent groups. The animals of one group were not completely unrelated to those in the other groups. They had common ancestors in many instances. A more vigorous test would ensure that members of a ha l f s ib group were unrelated to members of the other ha l f s ib groups in the study. Average daughter production data were ava i lab le for t h i r t y -one of the Holste in bu l l s from the Burl ington stud. This permitted a search for possible re lat ionships between the blood p ro f i l e s of the s i res and the i r daughter's production var iables which could be useful in the se lect ion of superior s i r e s . The study by Stark et a l . (1978) was the only paper found in the l i t e r a tu re to look at th i s aspect. With a much larger number of bu l l s with average daughter production data than was possible in th is study Stark et a l . (1978) were able to report s i gn i f i c an t corre lat ions between the blood t r a i t leve ls of urea-N, phosphorus, and potassium, and the improved contemporary comparisons (ICC's) for milk y i e l d . Their mult ip le regression analys is included g lobul in and potassium in the regression equation for milk y i e l d . They found no s i gn i f i can t re lat ionsh ips between the ICC's for butter fa t y i e l d , butter fa t percentage, or protein y i e l d and the blood t r a i t l eve l s . In the present study there were no s i gn i f i c an t corre lat ions between the blood t r a i t s and the average daughter production var iab les . A lka l ine phosphatase was the only blood t r a i t included in the regression 63 equations of mi lk y i e l d and predicted dif ference f a t . None of the blood t r a i t s were included in the regression equations for f a t , percent f a t , predicted di f ference mi lk , and predicted difference percent f a t . The a lka l ine phosphatase - milk y i e l d re lat ionsh ip possibly warrants further attent ion because a lka l ine phosphatase had a high repeatab i l i t y (0.65) which indicates possible genetic control of the blood t r a i t . Further invest igat ion may prove i t useful in s i re se lect ion for daughter milk production. A larger number of bu l l s with average daughter production data may y i e l d more promising resu l ts than those which occurred in th is study, in l i g h t of the resu l ts reported by Stark et a l . (1978). Thirty-one bu l l s do not provide a p a r t i c u l a r l y large data set to work with. AGE The contr ibut ion of age to the model is very small for a l l the blood t r a i t s . Cholestero l , glucose, a l ka l ine phosphatase, and b i l i r u b i n were assigned 1.90, 2.71, 3.15, and 3.51%, respect ive ly , of the tota l va r i a t i on . The other ten blood t r a i t s had less than 1% (.01 to .70%) of the tota l var ia t ion at t r ibuted to age. The bu l l s 64 in th i s study ranged from approximately one year to twelve years of age with a mean of four years. Nash (1978) in a study with dairy cows from a s im i la r age range also reported very low coef f i c ients of determination ( < 1.0%) for age with regards to the var ia t ion of the blood t r a i t s . The notable exceptions in his study were 7.2% for phosphorus and 15.4% for tota l prote in . Phosphorus and tota l protein had coe f f i c i en ts of determination of age of 0.6 and 0.4%, respect ive ly in the present study. The reasons for these wide discrepancies are not apparent. Phosphorus, glucose, cho les te ro l , b i l i r u b i n , a l ka l ine phosphatase, and SGOT had s i gn i f i c an t age ef fects in th is study. The regression coe f f i c ien ts can be found in Table 12; the pa r t i a l cor re la t ion coe f f i c i en ts in Table 14. There were negative r e l a t i on -ships between age and the four blood t r a i t s : phosphorus, glucose, cho les te ro l , and a lka l ine phosphatase. Pos i t ive re lat ionsh ips occurred between age and b i l i r u b i n , and, age and SGOT. The reports in the l i t e r a tu re on the ef fects of age on the blood t r a i t s of bu l ls are few in number. Most are studies of young animals less than three years old (Reid et a l . , 1948a; Arthaud et a l . , 1959; Roussel and S ta l l cup, 1966, 1967). The resu l ts of Reid et a l . (1948b) and Stark et a l . (1978) are from bu l l s of a wide range of ages (1 to 14 years) . The animals in the present study predominate 65 in the two to s ix year range but do extend from 0.82 years to 12.07 years. The papers by Peterson and Waldern (1981) and Nash (1978) present resu l ts for female dairy ca t t l e loca l to the region of th is study. Tumbleson et a l . (1973 a, b) studied a large number of female dairy ca t t l e spread over an age range of one to sixteen years. For these reasons reference w i l l be made to these papers report ing age ef fects in female dairy c a t t l e . Calcium, urea-N, ur ic a c i d , tota l prote in , albumin, l a c t i c dehydrogenase, sodium, and potassium were not s i gn i f i can t for age ef fects in th i s study. These resu l ts are not in to ta l agreement with the l i t e r a t u r e . Stark et a l . (1978) found no age ef fects for glucose, urea-N, sodium, and potassium but did report that calcium and phosphorus decreased with age. Reid et a l . (1948 a) found phosphorus to decrease with age while calcium increased in twelve Holstein bu l l s (18-33 months o ld ) . The resu l ts of Tumbleson et a l . (1973 a) agree with Stark et a l . (1978) for calcium, phosphorus, and sodium. Sodium was not s i gn i f i c an t l y affected by age (Tumbleson et a l . , 1973 a ) . Calcium and phosphorus were not affected by age according to the resu l ts of Peterson and Waldern (1981) but were affected in the study by Nash (1978). Phosphorus decreased with age in the present study. Calcium was not s i gn i f i can t for age e f fec t s . Sodium and potassium were not affected by age in th is study nor that by Stark et a l . (1978). Tumbleson et a l . 66 (1973 a) r e p o r t e d a d e c r e a s e i n p o t a s s i u m w i t h age , Sod ium was no t a f f e c t e d . Nash (.1978) f ound a s i g n i f i c a n t age e f f e c t on sod i um bu t no t p o t a s s i u m . Nash ( 1 9 7 8 ) , S t a r k e t a l . ( 1 9 7 8 ) , and A r t h a u d e t a l . (1959) r e p o r t e d g l u c o s e was no t s i g n i f i c a n t l y a f f e c t e d by age . G l u c o s e l e v e l s d e c r e a s e d w i t h age i n t h e p r e s e n t s t u d y . P e t e r s o n and Wa lde rn (1981) a l s o f ound a s i g n i f i c a n t age e f f e c t f o r g l u c o s e i n d a i r y cows . U r e a - N , u r i c a c i d , t o t a l p r o t e i n , and a l b u m i n were i n s i g n i f i c a n t f o r age a f f e c t s i n t h i s s t u d y and t h a t by P e t e r s o n and Wa lde rn ( 1 9 8 1 ) . U r ea -N was no t a f f e c t e d by age a c c o r d i n g t o S t a r k e t a l . ( 1 9 7 8 ) , where a s , Tumb leson e t a l . (1973 a) and Nash (1978) r e p o r t e d s i g n i f i c a n t age e f f e c t s . U r ea -N I n c r e a s e d w i t h age r e p o r t e d Tumbleson e t a l . (1973 a ) . Age was no t s i g n i f i c a n t f o r u r i c a c i d o r a l b u m i n bu t t o t a l p r o t e i n was (Na sh , 1 9 7 8 ) . R e i d e t a l . (1948 a) r e p o r t e d i n s i g n i f i c a n t age e f f e c t s f o r a l b u m i n and t o t a l p r o t e i n i n young H o l s t e i n b u l l s . Tumb leson e t a l . (1973 b) f ound t o t a l p r o t e i n l e v e l s i n c r e a s i n g w i t h age w i t h no s i g n i f i c a n t d i f f e r e n c e i n a l b u m i n l e v e l s whereas S t a r k e t a l . ( 1 9 7 8 ) r e p o r t e d a l b u m i n i n c r e a s e d between one and f i v e y e a r s o f age t hen d e c l i n e d t h e r e a f t e r . C h o l e s t e r o l and b i l i r u b i n were n o t s i g n i f i c a n t f o r age e f f e c t s (Na sh , 1 9 7 8 ) . C h o l e s t e r o l d e c r e a s e d w i t h age w h i l e b i l i r u b i n i n c r e a s e d i n t h e p r e s e n t s t u d y . P e t e r s o n and Wa lde rn (1981) r e p o r t e d c h o l e s t e r o l s i g n i f i c a n t f o r age e f f e c t s . The r e s u l t s o f t h e p r e s e n t s t u d y ag r ee w i t h t h o s e o f P e t e r s o n ( 1 9 7 4 ) , Rou s s e l and S t a l l cup ( 1 9 6 6 ) , 67 and Tumbleson et a l . (1973 b) that a lka l ine phosphatase leve ls decrease with age. Sengonca (1977) reported a lka l ine phosphatase leve ls increased with age in his study of bu l l s . Reid et a l . (1948 b) , and Petersen and Waldern (1981) found no s i gn i f i can t re lat ionsh ip between age and a lka l ine phosphatase l eve l s . Tumbleson et a l . (1973 b) reported that l a c t i c dehydrogenase in female dai ry ca t t l e increased un t i l about two years of age then decreased a f te r un t i l about ten years of age. These resu l ts do not agree with those of Roussel and Sta l lcup (1967) from forty-two Holstein Fr ies ian bu l l s which were less than two years o ld . They found l a c t i c dehydrogenase leve ls decreased with age in the i r animals. Peterson (1974) had l a c t i c dehydrogenase leve ls increasing with age in his growing Hereford bu l l s . Peterson and Waldern (1981) found a s i gn i f i can t negative age ef fect for l a c t i c dehydrogenase in dairy cows. Lact ic dehydrogenase did not have a s i gn i f i can t age ef fect in the present study. SGOT was not s i gn i f i can t for age ef fects in the studies of Roussel and Sta l lcup (1967), Tumbleson et a l . (1973b), Peterson and Waldern (1981) and Nash (1978). Boots e t a l . (1969) detected a s i gn i -f i can t quadratic age e f fec t in seventy-four calves (5 to 480 days old).SGOT increased with age in the present study. The var iable resu l ts reported in the l i t e r a tu re on the re lat ionships between age and the various blood t r a i t s indicate the po s s i b i l i t y of outside inf luences, (which were not taken into account 68 fay the researchers), a f fec t ing the leve l s of the blood t r a i t s . Tumbleson et a l . (1973a) have suggested that re lat ionships hetween age and some of the blood t r a i t s may be dependent upon environmental, managerial, and nut r i t i ona l factors inherent in the d i f fe rent studies. Kitchenham et a l . (1975) supported th i s view with the i r work on dairy calves reared under conventional and rapid-growth systems. They reported that rearing systems can inf luence changes in the concentrations of blood t r a i t s with age. For example, inorganic phosphate leve ls decreased from 9.0 mg/1OOml at three months to 7.9 mg/100 ml at nine months for the conventional ly reared ca lves, but there was no corresponding decrease for the rap id ly reared calves. Calcium concentrations appeared to fol low opposite trends for the d i f fe rent rearing systems. Age i s a measure of the passage of time from some f ixed point. The age ef fect indicates i f some sort of pattern in the changes of the blood t r a i t leve ls i s present across an in terva l of time. Age, i t s e l f does not cause any deviat ion in the leve ls of the blood t r a i t s . As the factors which are the underlying cause of age e f f ec t s , eg. nut r i t i ona l programs which a l t e r during the l i f e of an indiv idual from b i r th to adulthood, are i so lated or grouped with other related fac tors , eg. ind iv idual e f f ec t s , management un i t , herd, e t c . , the contr ibut ion of age ef fect diminishes: in importance. In th i s study and that by Nash (1978) the very low coef f i c ients of determination for age ef fects indicated that age, though s t a t i s t i c a l l y s i gn i f i c an t , had l i t t l e importance from a b io log ica l standpoint. 69 The factors, which contributed to the var ia t ion between and with in ind iv idua ls exerted much, more influence on the blood t r a i t s . With coe f f i c ien ts of determination of less than one percent age was not important i n the par t i t i on ing of the tota l variance of any of the blood t r a i t s . I t did not reduce the amount of the var ia t ion assigned to the residual term by an appreciable amount. The age e f f e c t ' s primary function in th i s study was to indicate i f any patterns existed in the changes of the blood t r a i t leve ls across time. The causes of the age ef fects appear to have been mostly accounted for by the other ef fects f i t t e d in the model. BREED Breed was a s i gn i f i can t e f fect for glucose, urea-N, l a c t i c dehydrogenase, and SGOT. I t accounted for 5, 6, 15 and 11 percent of the tota l va r i a t i on , respect ive ly . The only blood t r a i t s the mult ip le range tests were able to d i s t ingu ish separate breed groupings for were l a c t i c dehydrogenase and SGOT. The Blonde D' Aquitaine bu l l s had s i gn i f i c an t l y higher leve ls of SGOT than the Holstein and Guernsey bu l l s . Charolals and Angus bu l l s had s i gn i f i c an t l y higher leve ls of l a c t i c dehydrogenase than the Holstein and Guernsey bu l l s . Gelbvieh bu l l s had lower leve ls of l a c t i c dehydrogenase than the Charolais bu l l s . The mult ip le range tests indicate a grouping of breeds into beef and dairy types by the i r blood p ro f i l e s may be poss ib le. 70 The l i t e r a tu re reports, are not tn to ta l agreement as to the existence of breed differences in the blood t r a i t s . Calcium and phosphorus leve ls were not s i gn i f i c an t l y d i f fe rent between Holstein and Jersey cows, nor were they in Angus, Shorthorn, and Hereford cows and he i fe rs , and again not d i f fe rent in Jersey, Guernsey, and Holstein bu l l s according to the resu l ts of studies of Russoff and Piercy (1946), Long et a l . (1952), and Russoff et a l . (1954), respect ive ly . Other researchers have found breed effects for the minerals. Kitchenham and Rowlands (1976) had s ign i f i can t breed differences between the leve ls of calcium and potassium in Ayrshire and Fr ies ian cows. Sikes (1963) reported a s i gn i f i c an t breed e f fec t for the phosphorus leve ls of Guernsey, Jersey, and Holstein c a t t l e . Tumbleson et a l . (1973a) had s i gn i f i c an t l y higher calcium leve ls in Guernsey cows than in Holstein cows but no breed dif ference for phosphorus, sodium, and potassium. Rowlands ejt_al_J_ (1977) detected s i gn i f i c an t breed dif ferences in Devon, Sussex, Hereford, and Lincoln Red bu l l s for calcium, and sodium. Breed was not s i gn i f i can t for the minerals in the present study. Kitchenham and Rowlands (1976), and Tumbleson et a l . (1973 a) reported that no breed differences existed between Ayrshire and Fr ies ian cows and between Holstein and Guernsey cows, respect ive ly , for urea-N, whereas Rowlands et a l . (1977) did f ind breed differences in Devon, Sussex, Hereford, and Lincoln Red bu l l s . Urea-N was s ign i f i can t for breed in the present study. MacDonald et a l . (1956) 71 were the only researchers to look for breed dif ferences In ur ic ac id . They found Angus calves general ly had higher leve ls of u r i c acid than Hereford calves. Breed was not s i gn i f i can t in the present study for ur ic ac id . Glucose had a s i gn i f i can t breed ef fect in th i s study and also in those of Rowlands et a l . (1977) and Heyns (1971). Kitchenham and Rowlands (1976) reported that leve ls of to ta l protein were s i gn i f i c an t l y d i f fe rent between Ayrshire and Fr ies ian cows but that albumin leve ls were not. Tumbleson et a l . (1973b) could f ind no differences between Holstein and Guernsey cows fo r to ta l protein and albumin, whereas, Rowlands et a l . (1977) did f ind breed differences between several beef breeds and Herefords for albumin. Albumin and tota l protein did not have s i gn i f i can t breed ef fects in the present. Kunkel et a l . (1953) were unable to show s ign i f i can t breed differences between four European ca t t l e breeds whereas Russoff et a l . (1954) and Tumbleson et a l . (1973 b) did f ind s i gn i f i can t breed differences between the dairy breeds for a lka l ine phosphatase. A lka l ine phosphatase was not s i gn i f i can t for breed in the present study but l a c t i c dehydrogenase and SGOT were. Tumbleson et a l . (1973 b) reported no s i gn i f i can t breed ef fects for l a c t i c dehydrogenase and SGOT in Holstein and Guernsey ca t t l e . As the above discussion indicates the l i t e r a tu re reports are contradictory as to whether breed ef fects do ex i s t in the various blood t r a i t s . What may in fact be occurring in some studies i s a 72 masking of breed ef fects by other effects, which inf luence the blood t r a i t leve ls in a more d i rec t manner. Peterson and Waldern (1981) suggest that masking of genetic differences in dairy ca t t l e by physio logical ef fects may occur. Other researchers (eg. Tumbleson et a l . , 1973 a; Kitchenham et a l . ,1975) have reported that environmental, managerial, and nut r i t i ona l factors inherent in d i f fe rent studies inf luence the degree and d i rec t ion of the age - blood t r a i t r e l a t i on -ships which appear in the study. Var iat ion in the environmental inputs and the physio logica l states of the animals of d i f fe rent studies may have some inf luence as to what breed differences in the blood t r a i t s , i f any, are detected by researchers. Breed differences in the blood t r a i t s may be more prevalent in young stock. The factors which control the rate and to what degree animals grow and develop are at the i r strongest in immature animals. I t i s these factors which may contribute the most to differences in the blood p ro f i l e s of d i f fe rent breeds. Breed dif ferences in the blood p ro f i l e s may tend to disappear as the animals a t ta in maturity. I t may be that in order to obtain consistent and strong breed ef fects the researchers may have to s t r i c t l y control environmental inputs as much as poss ib le, standardize the sampling and storage procedures, and use animals of uniform ages and physio logical s tates. Breed differences in the blood t r a i t s may not be prevalent because of genetic s im i l a r i t i e s between the European breeds. Rouse (1970) discusses the or ig ins of the European breeds. They have evolved from two ancient types of c a t t l e , Bos primigenius and Bos longifrons 73 (or Bos, orachycerps). BOs longj f rons, i t s e l f may have had i t s ancestors in the Bos primigenius according to some author i t i es . Over the centuries t r i b a l migrations and conquests have caused the mixing of the ear ly ca t t l e types of Europe as they became d i f fe rent ia ted by e i ther natural or a r t i f i c i a l se lec t ion . The Introduction of ca t t l e into B r i t a i n from the European continent has occurred on several occasions. The Romans brought the i r ca t t l e when they invaded. Cat t le from northern Germany arr ived during various invasions from the f i f t h to the seventh centur ies. Invasions by the Norsemen and the Normans brought ca t t l e from Scandinavia and Normandy to the i s l and . The ca t t l e breeds of Guernsey and Jersey were developed from ca t t l e of north western France. More recent research by Kidd et a l . (1974) corroborates the statements of Rouse that there i s common ancestry between the ca t t l e breeds of Europe. Kidd et a l . (1974) reported that based on a comparison of ten immunagenetic l oc i of Gelbvieh and South Devon c a t t l e , these breeds are nearly as genet ica l ly s im i la r as red and black Angus. The resu l ts indicated that Gelbvieh and South Devon had a common ancestry on the continent and are d i s t i n c t from the other B r i t i s h breeds such as Hereford, Angus and Jersey. The sort ing of breeds into groups of common ancestry may y i e l d stronger breed ef fects in the blood t r a i t s than when comparing ind iv idua l breed p r o f i l e s . The mult ip le range test resu l ts also indicate the p o s s i b i l i t y of grouping breeds into beef or dairy breeds may accentuate breed e f fec t s . 74 A number of researchers have examined the growth t r a i t s of various breeds of c a t t l e . In pa r t i cu l a r , the U.S. Meat Animal Research Center in Nebraska has a very large ongoing study involv ing a large number of exot ic breeds of ca t t l e and the i r crossbreeds. They have gathered a large amount of information on the growth t r a i t s of these breeds. Other reports of smaller studies have come from Hutchinson (1957), Fredeen et a l . (1972), Barton (1977) and Pr ingle (1973). Breed differences have been detected in the growth t r a i t s of animals in these studies. I t i s not surpr is ing to f ind d i f f e r i ng growth and development patterns between the beef and dairy breeds, and between breeds with in these groups. These breeds were developed by se lect ion based on the phenotypic t r a i t s of growth rate , s i z e , shape, colour, carcass cha rac te r i s t i c s , milk production, etc . I t i s these t r a i t s which d is t ingu ish one breed from another. The l i t e r a tu re review gives the resu l ts of research into the re lat ionsh ips between the blood and growth t r a i t s . Pr ice (1959), Alexander et a l . (1958), Kruger and Lakanc (1968), Kunkel et al.(1953) and others have reported s i gn i f i can t corre lat ions between several blood t r a i t s , and growth t r a i t s , such as feed e f f i c i ency , rate of gain,and f i na l weight. I f high corre lat ions between blood t r a i t s and growth t r a i t s do ex i s t then i t may be possible to f ind s i gn i f i can t corre lat ions between the averages of the blood t r a i t s and the averages of the growth t r a i t s 75 for several breeds of c a t t l e . Do breeds with higher leve ls of a blood t r a i t exh ib i t higher or lower performance for a growth t r a i t ? Data on the growth t r a i t s of several breeds in th i s study were ava i lab le from the l i t e r a t u r e . The data provided an average index for each growth t r a i t of each breed. The growth t r a i t indices were corre lated to the average blood p ro f i l e s of the breeds. Table 7 has the average blood p ro f i l e of each breed and i t s corresponding growth t r a i t ind ices . Table 15 has the simple corre lat ions calculated between the blood and growth t r a i t s . There were eight s i gn i f i c an t corre lat ions between the blood and growth t r a i t s . Five of these included b i l i r u b i n which has a repeatab i l i t y of zero. This indicates a lack of genetic input. B i l i r ub i n leve ls are influenced by environmental fac tors . Without genetic control these resu l ts would appear to have occurred by chance. This conclusion i s supported by inspect ion of the data (Table 7) which shows a l l the breeds to have the same b i l i r u b i n leve ls except Jersey. Jersey i s also lower for the growth t r a i t s which i s not surpr is ing because i t i s a much smaller breed of c a t t l e . Further inspection reveals that the other s ix breeds exh ib i t f a i r l y wide var ia t ion in the i r growth t r a i t indices yet the b i l i r u b i n leve ls are the same for a l l . This occurred because b i l i r ub i n resu l ts are rounded to one s i gn i f i can t f igure by the bio-medical laboratory which analyzed the blood samples. The s ign i f i can t corre lat ions occurred because Jersey b i l i r u b i n was rounded to 2 mg/100ml whereas the others rounded to 3 mg/100 ml. There were no b i l i r u b i n leve ls between two and three mg/100 ml. 76 Urea-N had a s i gn i f i can t pos i t ive corre la t ion with pre-weaning average da i l y gain (0.72) in th i s study. Pr ice (1959) and Pr ice et al.(1959) reported urea-N was highly correlated with rate of gain and feed u t i l i z a t i o n e f f i c i ency in Hereford and Angus calves. They had a negative corre la t ion with rate of gain (-0.31). Kitchenham et a l . (1977) had pos i t i ve corre lat ions between urea-N and growth rate (0.44) and f i na l weight (0.38). Colby et al.(1950) found no s i gn i f i c an t corre lat ions between rate of gain in beef calves and the i r concentrations of urea-N. Ur ic ac id had s ign i f i can t negative corre lat ions with b i r th weight (-0.71) and weaning weight (-0.77) in the present study. Pr ice et al .(1959) reported ur i c acid s i gn i f i c an t l y correlated to rate of gain at both 500 and 800 lbs . (-0.30 and -0.35) in Hereford and Angus calves. None of the other blood t r a i t s had s i gn i f i can t corre lat ions with the growth t r a i t s in th i s study. The l i t e ra tu re review reveals that other researchers have encountered s ign i f i can t re la t ionsh ips . A lka l ine phosphatase was reported to be correlated to rate of gain; SGOT to body weight; and l a c t i c dehydrogenase to weight gain. Kitchenham et al.(1977) and L i t t l e et al.(1977) found that a l l s i gn i f i c an t corre lat ions became i n s i gn i f i c an t when the data were adjusted for to ta l feed intake. L i t t l e et a l . (1977) concluded that feed intake was the dominant factor which accounted almost en t i re l y for the s i gn i f i can t corre lat ions between weight gain and blood composition that were observed for glucose, phosphorus, sodium, and albumin. I t would seem that the most promising blood t r a i t s would be those which corre late 77 to the growth t r a i t s and are least affected by nut r i t i ona l fac tors . The enzymes may be worth further study in th i s regard because Gahne (1967) and Reid et al.( 1948a) reported a lka l ine phosphatase to be unaffected by the plane of nu t r i t i on and feed type. A lka l ine phosphatase correlated s i gn i f i c an t l y with rate of gain (Alexander et a l . ,1958; Ageraard, 1978; Kruger and Lakanc, 1968; Sengonca, 1977; and Kunkel et a l . , 1953). The enzymes were s i gn i f i c an t for breed ef fects in th i s study but did not corre late s i gn i f i c an t l y to the growth t r a i t s even though SGOT had quite high corre lat ions (0.36 to 0.54). This could be because of the small amount of data ava i lab le . There were only seven pairs of means used in each co r re la t i on . With only seven pairs of means per co r re l a t i on , the correlations had to be very large before they were s i gn i f i c an t ( >.707). With a larger number of breeds the cut o f f point for s ign i f i cance would drop. A lso, a better p icture of the blood-growth t r a i t re lat ionsh ips would appear because the corre lat ions would be based on more data. As the resu l ts stand in th i s study, the breeds with the higher leve ls of urea-N tend to have higher preweaning average da i l y gains. The breeds with the higher ur i c acid leve ls have lower b i r th weights and weaning weights. 78 SUMMARY AND CONCLUSIONS Blood samples drawn from 147 hu l l s representing ten breeds were analysed for fourteen blood t r a i t s . The blood p ro f i l e s compiled from these analyses were used in th i s study to see i f the read i ly apparent phenotypic differences such as coat colour, s i z e , carcass cha rac te r i s t i c s , e t c . , which occur between d i f fe rent breeds of ca t t l e were also accompanied by differences in the i r blood t r a i t l eve l s . Repeatab i l i t ies were calculated for each blood t r a i t . To test the hypothesis that blood t r a i t s under possible genetic control would show less var ia t ion with in groups of re lated animals than among unrelated animals, the blood p ro f i l e s of twelve ha l f s ib groups were compared. Corre lat ing the blood p ro f i l e s to several t r a i t s of economic importance provided ins ight into the possible usefulness of the p ro f i l e s in the se lect ion of breeding stock. The blood p ro f i l e s of th i r ty-one Holstein bu l l s were correlated to the i r average daughter milk production var iab les. The re lat ionships between the blood p ro f i l e s and the growth t r a i t s were looked at by comparing the mean blood p ro f i l e s of several breeds to the i r respective growth t r a i t means. The ranges and means of the blood t r a i t s of th i s study compared quite favourably to the l i t e r a tu re reported means for cows and bu l l s . Inspection of the tables revealed s im i la r p ro f i l e s in male and female c a t t l e . 79 Age was s i gn i f i can t for phosphorus, glucose, cho les tero l , b i l i r u b i n , a l ka l ine phosphatase, and SGOT. Phosphorus, glucose, cho les te ro l , and a lka l ine phosphatase leve ls decreased with age, whereas, SGOT and b i l i r u b i n increased with age. The very low coef f i c ients of determination for age ef fect in th i s study indicate that age, though s t a t i s t i c a l l y s i gn i f i c an t , had l i t t l e importance b i o l og i c a l l y . I t d id not appreciably reduce the residual va r i a t i on . The underlying causes of the changes of the blood t r a i t leve ls over time appear to have been mostly accounted for by the other ef fects f i t t e d in the model. The s t a t i s t i c a l model was e f f i c i e n t for a l l the blood t r a i t s . The port ion of the overa l l var ia t ion of the blood t r a i t s at t r ibuted to the f i t t e d ef fects ranged from 0.42 to 0.87. The var ia t ion between ind iv idua ls received the largest share of th i s partioned var ia t ion for each blood t r a i t (0.27 to 0.58). The other ef fects general ly had much smaller contr ibut ions. The var ia t ion between repeated samples from an ind iv idua l (res idual) was also important (0.12 to 0.57). The var ia t ion between ind iv idua ls was s i gn i f i c an t l y greater than the within ind iv idua ls var ia t ion for phosphorus, urea-N, ur ic ac id , to ta l prote in , albumin, a lka l ine phosphatase, and SGOT which indicates the de f in i te i nd i v i dua l i t y of the blood p ro f i l e s of bu l l s . The repea tab i l i t i e s of the blood t r a i t s ranged from 0 to 65 percent. The low repea tab i l i t i e s of cho les tero l , b i l i r u b i n , 80 calcium, glucose, l a c t i c dehydrogenase, sodium and potassium reveal the i r susceptab i l i t y to temporary environmental inf luences. Genetic inf luences would appear to be of l i t t l e importance in these t r a i t s . The other seven blood t r a i t s : phosphorus, urea-N, ur i c ac id , tota l prote in , albumin, a l ka l i ne phosphatase, and SGOT, had moderate (0.20) to high (0.65) r epea tab i l i t i e s . The high repeatab i l i t y of a lka l ine phosphatase (0.65) may r e f l e c t the inf luence of semen co l l e c t i on during blood sampling. The i nd i v i dua l i t y of the blood p ro f i l e s and the high repeata-b i l i t i e s of several blood t r a i t s lend support to the po s s i b i l i t y that the blood p ro f i l e could be useful i n the se lect ion of breeding stock i f any strong re lat ionsh ips between the blood p ro f i l e and the t r a i t s of economic importance could be found. Even though other researchers have reported s i gn i f i c an t l y less var ia t ion among re lated animals for several blood t r a i t s , th i s study was unable to do so. The many in ter - re la t ionsh ips between animals of d i f fe rent ha l f s ib groups was l i k e l y a major factor contr ibut ing to the lack of s i gn i f i can t resu l t s . The ideal s i t ua t i on , whereby a l l the animals of each ha l f s ib group are not re lated to members of other ha l f s ib groups, was unfortunately not poss ib le. 81 There were no s i gn i f i can t corre lat ions between the blood and milk t r a i t s . A lka l ine phosphatase was the only blood t r a i t included in the regression equations of mi lk y i e l d and predicted dif ference f a t . The regression equations of the other milk var iables did not include any blood t r a i t s . The high repeatab i l i t y of a lka l ine phosphatase (0.65) which indicates some degree of genetic control of the blood t r a i t suggests that further study of the a lka l ine phosphatase-milk y i e l d re lat ionsh ips i s warranted. A large data set may have y ie lded better ins ight into the re lat ionsh ips of s i re blood p ro f i l e to daughter milk production. There were eight s i gn i f i c an t blood t r a i t - growth t r a i t cor re la t ions . Five of the eight s i gn i f i can t corre lat ions involved b i l i r u b i n which had a repeatab i l i t y of zero. These corre lat ions appear to have occurred by chance because the low repeatab i l i t y of b i l i r u b i n indicates a lack of genetic control on the blood t r a i t . The only other s i gn i f i c an t corre lat ions were: urea-N to pre-weaning average da i l y gains (0.72), ur ic acid to b i r th weight (-0.71), and ur i c acid to weaning weight (-0.77). With only seven pai rs of means per co r re l a t i on , the corre lat ions had to be very large before they were s i gn i f i can t (>0.707). With a larger data set the cut o f f point for s ign i f i cance would drop and a better p icture of the blood - growth t r a i t re lat ionsh ips would appear. As the resu l ts stand, the breeds with the higher leve l s of urea-N tend to have higher pre-weaning average da i l y gains. The breeds with the higher ur i c acid leve ls have lower -82-b i r th and weaning weights. Breed was not a major contr ibutor to the var ia t ion of the blood t r a i t s . Of the four blood t r a i t s with s i gn i f i can t breed ef fects only urea-N and SGOT look promising. Glucose and l a c t i c dehydrogenase have low repea tab i l i t i e s which indicates that the i r s i gn i f i can t breed e f fec t probably occurred by chance. The mult ip le range tests were able to d is t ingu ish separate breed grouping of l a c t i c dehydrogenase and SGOT. The mult ip le range tests indicated a grouping of breeds into beef and da i l y types by the i r blood p ro f i l e s may be poss ib le. Var iat ion in the environmental inputs and the physio logical states of the animals of d i f fe rent studies may have some inf luence as to what breed e f f ec t s , i f any, are detected by researchers. One aspect of th i s i s that breed differences may be more prevalent in young stock. The factors which control growth and development may contr ibute the most to differences in the blood p ro f i l e s of d i f fe rent breeds. These differences may tend to disappear as the animals mature. Breed differences in the blood t r a i t s may not be prevalent because of genetic s im i l a r i t i e s between the European breeds. More extensive breed differences in the blood p ro f i l e s of ca t t l e may come to l i gh t in subsequent studies i f sort ing of the breeds into genet ica l ly s im i l a r groups i s performed. Expansion of the p ro f i l e to include other enzymes and protein f ract ions might also prove f r u i t f u l . 83 BIBLIOGRAPHY Agergaard, N. 1978. Plasma a lka l ine phosphatase a c t i v i t y and growth in ca lves. Animal Breeding Abstracts. 46:422 #3736 (Abst r . ) . Agergaard, N. and J . Katholm. 1978. Plasma a lka l ine phosphatase a c t i v i t y and isoenzyme composition as an ind icat ion of growth in calves. Animal Breeding Abstracts. 46:311 #2646 (Abs t r . ) . Agr icu l ture Canada. 1977. Quebec ROP beef s tat ion t e s t s , 1976 - 77. Canadex Beef Performance 420.41 October. Alexander, G . I . , H. Krueger and R. Bogart. 1958. 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The weights were divided by the weaning weight of Angus and mul t ip l i ed by 100 to y i e l d the indices for weaning weight. Breed # Index Angus 1003 (201/201)xl00 = 100 Charolais 1237 (290/201)xl00 = 144 Limousin 173 (239x201)x!00 = 119 Simmental 627 (282/201)xl00 = 140 This indices had to be weighted to take into account the number of animals contr ibut ing to each index. The weighting was calculated by the formula: 93 W = n.i x n.2 n.i •+ n.2 where W = the weighting m = the number of animals in the non-Angus breed n2 -Breed = the number of Angus ca t t l e Weighting Index Angus Charolais Limousin Simmental 1003 1237 173 627 1237x1003 1237+1003 173x1003 173+1003 627x1003 627+1003 554 148 386 100 144 119 140 The weightings are mul t ip l i ed by the i r corresponding indices from a l l the sources of data. For each breed the weightings are added up, as are the "weightings times the index", and the tota l "weighting times the index" divided by the to ta l weighting to y i e l d the average index. CHAROLAIS WEANING WEIGHT Index Weighting Wxl 144 554 79776 110 87 9570 105 35 3675 108 46 4968 772 97989 TOTAL Average Index = 97989 * 772 = 136 94 The average index for charola is weaning weight was 136. This procedure was repeated for the weaning weights of the other breeds and for the remaining growth t r a i t s . For those references which had information only on crossbred animals the indices were adjusted for 5% heterosis (Preston and W i l l i s (1974)) to obtain estimates for the purebred performance. A l l the crossbred references contained purebred Angus and Angus crossbreds. An example fo l lows. ORIGINAL DATA Breed # B i r th Wt.(kg) Angus x Angus 66 73.5 Jersey x Angus 71 68.5 The indices were ca lcu la ted. Breed Index Angus x Angus 100 Jersey x Angus (68.5/73.5)xl00 = 93 The crossbred index was adjusted with the formula: Where JJ = purebred Jersey index JA = Jersey x Angus index 95 J J ^n^yp) • 1 0 0 = 7 7 The birthweight index for purebred Jersey was 77. The weighting was calculated and included with the adjusted index in the average index ca l cu la t i on .