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Covariance matrices for growth traits of Australian Polled Hereford cattle

Published online by Cambridge University Press:  02 September 2010

K. Meyer
K. Meyer
Affiliation:
Animal Genetics and Breeding Unit, University of New England, Armidale, NSW 2351, Australia
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Abstract

Estimates of covariance components due to direct and maternal effects among birth, weaning, yearling and final weight for Australian Polled Herefords were obtained by restricted maximum likelihood fitting an animal model. Data were obtained from commercial herds participating in the National Beef Recording Scheme and an across-herd genetic evaluation service. Analyses were carried out considering nine subsets of data, each comprising at least 3000 weaning, 1000 yearling and 500 final weight records which yielded a total of 30 506,17 105 and 9486 records for the three weights, respectively. Estimates of variances and genetic parameters varied considerably between data sets. Both genetic and permanent environmental effects were found to affect all traits except final weights significantly, with maternal environmental effects explaining proportionately more than 0·20 of the total variation in weaning weight. Estimates of the direct-maternal genetic correlation were consistently negative and moderate to strong, ranging from -0·34 to -0·82 for weaning weight. Maternal correlations between weaning and yearling weights were close to unity. Estimates of the direct genetic correlations among the three later weights were 0·8 or larger. Problems with this kind of analysis are discussed.

Keywords

beef cattlegenetic parametersgrowthmaternal effects
Type
Research Article
Information
Animal Production , Volume 57 , Issue 1 , August 1993 , pp. 37 - 45
Copyright
Copyright © British Society of Animal Science 1993

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References

Cundiff, L. V. 1972. The role of maternal effects in animal breeding. VIII. Comparative aspects of maternal effects. Journal of Animal Science 35:1335–1337.Google Scholar
Hayes, J. F. and Hill, W. G. 1980. A reparameterization of genetic selection index to locate its sampling properties. Biometrics 36: 237–248.Google Scholar
Hayes, J. F. and Hill, W. G. 1981. Modification of estimates of parameters in the construction of genetic selection indexes (‘bending’). Biometrics 37:483–493.Google Scholar
Johnsson, I. D. and Morant, S. V. 1984. Evidence of a negative relationship between heifer growth and first calf weaning weight in commercial beef herds. Australian Journal of Experimental Agriculture and Animal Husbandry 10–14.Google Scholar
Koots, K. R., Gibson, J. P. and Wilton, J. W. 1991. Analysis of genetic parameters for beef cattle. Journal of Animal Science 69: suppl. 1, pp. 205–206 (abstr.).Google Scholar
Meyer, K. 1989. Restricted maximum likelihood to estimate variance components for animal models with several random effects using a derivative-free algorithm. Genetique, Selection, Evolution 21: 317–340.CrossRefGoogle Scholar
Meyer, K. 1991a. Estimating variances and covariances for multivariate animal models by restricted maximum likelihood. Genetique, Selection, Evolution 23: 67–83.CrossRefGoogle Scholar
Meyer, K. 1991b. DrReml version 2·0 · programs to estimate variance components by restricted maximum likelihood using derivative-free algorithm. User notes. Animal Genetics and Breeding Unit, University of New England, Armidale, NSW. Mimeo.Google Scholar
Meyer, K. 1992a. Variance components due to direct and maternal effects for growth traits of Australian beef cattle. Livestock Production Science 31:179–204.Google Scholar
Meyer, K. 1992b. Bias and sampling covariances of estimates of variance components due to maternal effects. Genetique, Selection, Evolution 24: 487–509.Google Scholar
Meyer, K. 1993. Estimates of direct and maternal correlations among growth traits in Australian beef cattle. Livestock Production Science In press.Google Scholar
Meyer, K., Carrick, M. J. and Donnelly, B. J. P. 1992. Estimates of covariance components for growth traits for the Wokalup single- and multi-breed research herds. Proceedings of the tenth conference of the Australian Association for Animal Breeding and Genetics, Rockhampton, pp. 427–430.Google Scholar
Schneeberger, M., Tier, B. and Hammond, K. 1991. Introducing the third generation of Breedplan And Groupbreedplan. Proceedings of the ninth conference of the Australian Association of Animal Breeding and Genetics, Melbourne.Google Scholar
Swalve, H. H. 1993. Estimation of direct and maternal (co)variance components for growth traits in Australian Simmental beef cattle. Journal of Animal Breeding and Genetics In press.Google Scholar
Waldron, D. F., Morris, C. A., Baker, R. L. and Johnson, D. L. 1993. Maternal effects for growth traits in beef cattle. Livestock Production Science 34: 57–70.Google Scholar
Willham, R. L. 1972. The role of maternal effects in animal breeding. III. Biometrical aspects of maternal effects in animals. Journal of Animal Science 35:1288–1293.CrossRefGoogle Scholar