Data used in this study were taken from performance test records of Hereford, Aberdeen-Angus and Shorthorn sires and their progeny that were raised and performance tested at the Arkansas Agricultural Experiment Station during the years 1951 through 1962. Heritability estimates based on regression of offspring on sire were obtained from 201 male progeny belonging to 20 sire groups. The estimates obtained were 0.19±0.19 for 120-day weight, 0.27±0.13 for initial test weight, 0.93±0.18 for test daily gain, 0.43± 0.18 for feed consumption, 0.41±0.25 for feed conversion, 0.15±0.15 for type score, 0.37± 0.14 for final test weight, and 0.79±0.18 for production index

Brown, C. J.

Gacula, Maximo

English

WBI Studies Repository (WellBeing International)

WellBeing International WBI Studies Repository 5-1964 Estimates of Heritability of Beef Cattle Performance Traits by Regression of Offspring on Sire C. J. Brown University of Arkansas, Fayetteville Maximo Gacula University of Arkansas, Fayetteville Follow this and additional works at: https://www.wellbeingintlstudiesrepository.org/geneti  Part of the Animal Studies Commons, Other Animal Sciences Commons, and the Other Genetics and Genomics Commons Recommended Citation Brown, C. J., & Gacula, M. (1964). Estimates of Heritability of Beef Cattle Performance Traits by Regression of Offspring on Sire 1, 2. Journal of Animal Science, 23(2), 321-324. https://doi.org/10.2527/jas1964.232321x This material is brought to you for free and open access by WellBeing International. It has been accepted for inclusion by an authorized administrator of the WBI Studies Repository. For more information, please contact wbisr-info@wellbeingintl.org. ESTIMATES OF HERITABILITY OF BEEF CATTLE PERFORMANCE TRAITS BY REGRESSION OF OFFSPRING ON SIRE 1, 2 C. J. BROWN AND MAXII~O GACULA University o/Arkansas, Fayetteville E STIMATES of heritability of economic traits in beef cattle vary according to methods of estimation, sources of environ- mental effects and genetic variability of the population being studied. In populations where parents are selected and offspring unselected, the regression of offspring on parent leads to a reliable estimate of heritability (Lush, 1948). In  beef cattle populations, because of difficulties encountered in obtaining suitable data, few heritability estimates have been derived from the regression of progeny per- formance on sire preformance. Using this procedure heritability estimates of eight per- formance traits of beef bulls fed on postwean- ing gain tests were obtained and are reported in this study. Mater ia ls  and Methods  Data studied were the performance records of sires that were raised, performance tested and selected for use in Arkansas Agricultural Experiment Station herds and the performance test records of their male progeny. There were records of 20 sires, with 201 progeny, tested between 1951 and 1962. The breed and number of progeny tested in each sire progeny group are given in table 1. During the performance test calves were individually fed a ration of one-third prairie hay and two-thirds grain mixture for 154 days. Grain intake was limited according to the weight of daily hay intake. Performance tests were started either in mid-May or mid-Novem- ber. Gains were calculated from initial and final weights on test. Feed consumption was the total feed eaten during the test period and, because of the daily adjustment of grain to hay intake, was one-third hay and two- thirds grain. Performance test procedures were described in detail by Brown and Gifford (1962). Type scores were taken near the end of the feeding period using the score- card described by Brown et al. (1953). 1 Published with approval of the Director of the Arkansas Agricultural Experiment Station. A publication of Southern Regional Beef Cattle Breeding Project, S-10. At the end of the test a production index was calculated for each bull, which gave equal emphasis to 120-day weight (X1), average daily gain on test (Xe), feed conversion on test (X3), and type score (X4). The formula for this index was: lO Production Index_-- 75 +~- [ (x~-x~) 4 _ _  S~ $2 $3 where Xi is an observation, Xi is the mean and si is the standard deviation of the trait considered. In a preliminary analysis it was determined that there were differences between tests which must be taken into account, since a sire and his offspring were evaluated in differ- ent tests. The differences between tests have been shown to account for 14 to 26% of the variance in these traits (Brown and Gifford, 1962). In order to standardize the data for test differences, the record of each bull for each trait was expressed as a devia- tion from the mean of the group with which he was tested. In table 2 is presented the range of the observations of sires and sons for the eight performance traits studied. These values are expressed as deviations from the average of test contemporaries. There is a slightly greater range for all traits in the record of sires than there is in the range of the averages of their sons. The regression coefficients of offspring records on sires' records were calculated using the deviations of each trait. Heritability esti- mates and standard errors based on regression coefficients were calculated by three different methods. Method 1 was the regression of the mean of the sons' records on sires' records. Method 2 was the regression of sons' records on sires' records with the sires' records re- peated for each son. Method 3 was the weighted regression technique described by Kempthorne and Tandon (1953) and elab- orated on by Bohren et al. (1961). 321 322 B R O W N  AND GACULA TABLE 1. BREED OF SIRE SHOWING NUMBER OF SONS TESTED No. of Sire no. Breed ~ progeny U257 A 2 U336 A 3 U414 A 4 U462 A 23 U615 A 18 U195 A 2 L2 A 4 L9 A 18 L397 A 10 L413 A 17 L414 A 16 U221 H 14 U267 H 17 U268 H 5 U411 H 25 U533 H 5 R820 H 3 G858 H 6 Ul15 S 7 U138 S 2 a AzAberdeen-Angus, HzHereford,  SzShorthorn. R e s u l t s  a n d  D i s c u s s i o n  Heri tabil i ty estimates of the eight perform- ance traits are shown in table 3. These esti- mates are on a within-sex basis since only bull calves were fed on test. They are on a within-test basis because of the procedure used to standardize for test differences. Since only British breeds with similar performance were included, the analysis was not made on a within-breed basis and any breed differ- ences would tend to inflate the heritabili ty estimates. According to Dickerson (A.S.A.P., 1960) the coefficient from the sire offspring regression arises from 50% of the additive effects, 25% of the covariance between genetic deviations in the transmitted and the direct maternal  effects, 25% of the two-loci interactions and a small amount  of the higher order interactions. Except for 120-day weight and initial test weight, the traits studied should be uncomplicated by maternal  effects. The estimates of heritabil i ty obtained by the three methods are presented in table 3. The relative efficiencies of these three methods of estimation were compared by McKean and Bohren ( 1961) who indicated that methods 2 and 3 are preferred over method 1. Method 3 is preferred over method 2 provided a reli- able estimate of the correlation between the deviations of two offspring of the same parent  from the predicted breeding value of the parent  can be estimated and this correlation is high. These workers point out in certain circumstances a poor choice of method can lead to a serious loss in efficiency in estima- tion of the regression coefficient and thus heritability in the narrow sense. I t  is of inter- est to note in this respect that  the heritabili ty of the eight traits estimated in this study do not differ greatly when obtained by the three methods. The greatest difference among the three estimates was in final weight for which the estimates were 0.19, 0.40 and 0.37 for methods 1, 2 and 3, respectively. In  the following discussion reference is made only to estimates obtained by method 3. The estimate of heritabil i ty of 120-day weight was 0 .1920 .19 .  No other published TABLE 2. THE RANGE OF SIRE'S RECORD AND AVERAGE SONS' RECORDS EXPRESSED AS A DEVIATION FROM THE MEAN OF THEIR CONTEMPORARY TEST GROUP Trait Sire Sons' average Largest deviation Largest deviation below average above average Largest deviation Largest deviation below average above average 120-day weight, lb. --41 79 --49 23 Initial test weight, lb. --187 173 --65 36 Test av. daily gain, lb./day --.4 0.5 -- .4 0.3 Total feed consumption, lb. --677 676 --328 221 Feed conversion, lb. feed/lb, gain --3.0 4.0 --1.0 2.0 Type score, scorecard points --9 14 --7 4 Final test weight, lb. --162 214 --52 41 Production index, index points -- 10 12 --8 9 ESTIMATES OF HERITABILITY IN BEEF CATTLE 323 TABLE 3. H E R I T A B I L I T Y  E S T I M A T E S  AND STANDARD ERRORS BASED ON R E G R E S S I O N  C O E F F I C I E N T S  E S T I M A T E D  BY T H R E E  D I F F E R E N T  M E T H O D S  Method  Performance t ra i t  1 ~ 2 b 3 ~ 120-day weight  0 . 1 8 + 0 . 2 5  0 . 2 8 •  0.19-+0.19 Ini t ia l  test weight  0.15-+0.18 0.27--+0.09** 0.27-+0,13" Average daily gain 0.80-+-0.18"* 0.96___0.13"* 0.93___0.18"* Feed consumption 0.43___0.21 0.43__+0.10" 0.43-+0.18"* Feed conversion r 0 .35-+0.27 0.42__+0.13"* 0.41-+0.25 Final  test weight  0 .19-+0.14 0.40--+0.10'* 0 .37-+0.14"* Type score 0.11-4-0.22 0.21-+0.12 0.15-+0.15 Product ion index 0. 77_+0. 29* 0 .80-+0 .18 '*  0. 79-+0.18"* ** Regression of progeny average on site's record. b Sire's record repeated for each progeny record. e Kempthorne-Tandon weighted regression technique. d Adjusted for differences in initial weight. .2 Regression coefficient significant (P<.05). ~ Regression coefficient significant (P<.01). estimate of this trait in beef cattle was avail- able. Differences in 120-day weight are ex- pected to be largely the result of differences in maternal environment provided by the dam. Weight taken at this age expresses maternal environment more accurately than weights taken later in the preweaning period, because some calves are able to eat enough to com- pensate for low milk production of their dams. Since differences in maternal environment are not genetic insofar as the calf is concerned, a heritability estimate of this trait would be expected to be low. The estimate of heritability of initial test weight was comparable to estimates of herit- ability of weaning weight in many studies since the bulls were started on test about 2 weeks after weaning. The average age of calves when started on test was 235 days. The heritability estimate of initial test weight was 0.27• This trait is influenced by maternal environment in the same manner as 120-day weight, but to a lesser extent. This estimate is in agreement with recent estimates from more extensive data of which these are a part and the studies of Koch and Clark (1955), Lasley et al. (1961) and Blackwell et al. (1962). The heritability estimate of gain on per- formance test was 0.93--+0.18. This was the most highly heritable trait included in this study. Heritability of this magnitude indicates the considerable genetic improvement which ought to be possible through phenotypic selec- tion for rate of gain. The estimate obtained in this study is higher than an average herit- ability value for gain in feedlot of 0.53 esti- mated by sire-offspring regression method that may be calculated from the reports of Knapp and Clark (1950), Knapp and Nordskog (1946), Carter and Kincaid (1959), and Chambers et al. (1960). The estimate of heritability of total feed consumption was 0.43__+0.18. This is smaller than the value of 0.76 obtained in a paternal half-sib analysis of the data from which these sire progeny groups were taken (Brown and Gifford, 1962). I t  is in close agreement, how- ever, with the estimate of 0.38 by England et al. (1961), the estimate of 0.45--+0.46 and 0.38+0.36 reported by Swiger (1961) and the combined estimate of 0.64--+0.12 reported by Koch et al. (1963). The heritability estimate of feed conver- sion in this study was 0.41+0.25 which is less than the value of 0.80 obtained by Brown and Gifford (1962). This difference in esti- mates from the same body of data could be the result of sampling or of different methods of estimation. Carter and Kincaid (1959) reported 0.22 for heritability of feed conver- sion calculated from offspring-sire regression. Other estimates obtained by paternal half-sib procedures were 0.22 and 0.32 by Shelby et el. (1955, 1960), 0.27 and 0.36 by Lickley et al. (1959) and 0.36 by Koch et al. (1963). The estimate of 0.15• for heritability of type score was low. This value is much smaller than the 0'.58 reported by Brown and Gifford (1962) in the paternal half-sib analysis. The reason for this wide difference is not clear. Heritability estimates for type score and grade reviewed in the literature ranged from 0.16 to 0.63 with an average of 0.41. The heritability estimate of final test weight was 0.37-+-0.14. This is below the esti- mate of 0.85 reported by Brown and Gifford (1962) and others reviewed. Estimates of heritability of final feedlot weight based on 324 B R O W N  A N D  G A C U L A  offspring-sire regression were  0.92 by  K n a p p  and C la rk  (1950)  and 0.54 by  Chamber s  et al. (1960) .  An  average  of recent  es t imates  ob ta ined  by  pa te rna l  half-s ib me thods  by  She lby  et al. (1960, 1963),  Swiger  (1961)  and  Blackwel l  et al. (1962)  was  0.62. T h e  he r i t ab i l i ty  e s t ima te  ob ta ined  for the p roduc t ion  index  was 0.79+_0.18. T h i s  index was a rb i t r a r i ly  chosen to give equa l  emphas is  to 120-day weight ,  tes t  da i ly  gain,  feed con- vers ion and type  score. T h e  her i t ab i l i ty  esti-  m a t e  was high. Pe rhaps  the  averag ing  of t ra i t s  in ca lcu la t ing  the  index cancel led some of the  errors  in eva lua t ion .  Such an index migh t  h a v e  va lue  for  expressing genera l  genet ic  po ten t ia l  for beef  p roduc t ion  of a bul l  when  the herd  s i tua t ion  in which  he  will  be used is unknown.  Summary Data used in this study were taken from performance test records of Hereford, Aber- deen-Angus and Shorthorn sires and their progeny that were raised and performance tested at the Arkansas Agricultural Experi- ment Station during the years 1951 through 1962. Heritability estimates based on regres- sion of offspring on sire were obtained from 201 male progeny belonging to 20 sire groups. The estimates obtained were 0.19___0.19 for 120-day weight, 0.27+__0.13 for initial test weight ,  0.93 +_0.18 for tes t  da i ly  gain, 0.43 • 0.18 for feed consumpt ion ,  0.41 _+0.25 for feed convers ion,  0 .15+-0.15 for type  score, 0.37_+. 0.14 for final tes t  weight ,  and 0.79___0.18 for p roduc t ion  index.  L i t e r a t u r e  C i t e d  A.S.A.P. 1960. Techniques and Procedures in Animal Production Research. American Society of Animal Production. Blackwell, R. L., J. H. Knox, C. E. Shelby and R. T. Clark. 1962. Genetic analysis of economic charac- teristics of young Hereford cattle. J. Animal Sci. 21:101. Bohren, B. B., H. E. McKean ad Yukio Yamada. 1961. Relative efficiencies of heritability estimates based on regression of offspring on parent. Bio- metrics 17:481. Brown, C. J. and Warren Gifford. 1962. Estimates of heritability and genetic correlations amomg certain traits of performance-tested beef bulls. Ark. Agr. Exp. Sta. Bul. 653. Brown, C. J,, W. Gifford and M. L. Ray. 1953. A subjective method for evaluating conformation of beef cattle--permanency and accuracy of confor- mation scores. Ark. Agr. Exp. Sta. Bul. 540. Carter, R. C. and C. M. Kincaid. 1959. Estimates of genetic and phenotypic parameters in beef cattle. II. Heritability estimates from parent-offspring and half-sib resemblances. J. Animal Sci. 18:323. Chambers, D., J. B. Armstrong and D. F. Stephens. 1960. Progeny testing beef bulls for growth. Okla. Agr. Exp. Sta. Misc. Publ. MP-64. England, N., J. Brinks, R. Bogart and R. T. Clark. 1961. Evidence for genetic influence on appetite in beef cattle, J. Animal Sci. 20:905 (Abstr.). Kempthorne, O. and O. B. Tandon. 1953. The estima- tion of heritability by the regression of offspring on parent. Biometrics 9:90. Knapp, B. and R. T. Clark. 1950. Revised estimates of heritability of economic characteristics of beef cattle. J. Animal Sci. 9:582. Knapp, Bradford, Jr. and A. W. Nordskog. 1946. Heritability of growth and efficiency in beef cattle. J. Animal Sci. 5:62. Koch, R. M. and R. T. Clark. 1955. Genetic and en- vironmental relationships among economic charac- ters in beef cattle. II. Correlations between off- spring and dam and ~ offspring and sire. J. Animal Sci. 14: 786. Koch, Robert M., L. A. Swiger, Doyle Chambers and K. E. Gregory. 1963. Efficiency of feed use in beef cattle. J. Animal Sci. 22:486. Lasley, J. F ,  B. N. Day and J. E. Comfort. 1961. Some genetic aspects of gestation length and birth and weaning weights in Hereford cattle. J. Animal Sci. 20:737. Lickley, C. R., H. H. Stonaker, T. M. Sutherland and K. H. Riddle. 1959. Relationship between ma- ture size, daily gain, and efficiency of feed utilization in beef cattle. J. Animal Sci. 18:957 (Abstr.). Lush, J. L. 1948. The Genetics of Populations. Ames, Iowa (Mimeo.). McKean, H. E. and B. B. Bohren. 1961. Numerical aspects of regression of offspring on parent. Bio- metrics 17:626. Shelby, C. E., R. T. Clark, J. R. Quesenberry and R. R. Woodward. 1960. Heritability of some eco- nomic characteristics in records of performance bulls. J. Animal Sci. 19:450. Shelby, C. E., R. T. Clark and R. R. Woodward. 1955. The heritability of some economic charac- teristics of beef cattle. J. Animal Sci. 14:372. Shelby, C. E., W. R. Harvey, R. T. Clark, J. R. Quesenberry and R. R. Woodward. 1963. Estimates of phenotypie and genetic parameters in ten years of Miles City R.O.P. steer data. J. Animal Sci. 22:346. Swiger, L. A. 1961. Genetic and environmental in- fluences on gain of beef cattle during various pe- riods of life. J. Animal Sci. 20:183. 

Estimates of Heritability of Beef Cattle Performance Traits by Regression of Offspring on Sire

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Estimates of Heritability of Beef Cattle Performance Traits by Regression of Offspring on Sire

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