Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-28T05:14:26.471Z Has data issue: false hasContentIssue false
  • English
  • Français

Correlated responses to selection for cow fertility in a tropical beef herd

Published online by Cambridge University Press:  02 September 2010

M. J. Mackinnon ,
D. J. S. Hetzel ,
N. J. Corbet ,
R. P. Bryan  and
R. Dixon
M. J. Mackinnon
Affiliation:
CSIRO, Division of Tropical Animal Production, Tropical Cattle Research Centre, North Rockhampton, Queensland 4702, Australia
D. J. S. Hetzel
Affiliation:
CSIRO, Division of Tropical Animal Production, Tropical Cattle Research Centre, North Rockhampton, Queensland 4702, Australia
N. J. Corbet
Affiliation:
CSIRO, Division of Tropical Animal Production, Tropical Cattle Research Centre, North Rockhampton, Queensland 4702, Australia
R. P. Bryan
Affiliation:
CSIRO, Division of Tropical Animal Production, Tropical Cattle Research Centre, North Rockhampton, Queensland 4702, Australia
R. Dixon
Affiliation:
CSIRO, Division of Tropical Crops and Pastures, Davies Laboratory, Townsville, Queensland 4814, Australia
Get access

Abstract

Correlated responses to selection in a tropical beef herd for high (H) and low (L) estimated breeding value for pregnancy rate were measured over three calf crops. The H line calves were proportionately 0·04 lighter at weaning but during the ensuing dry season they lost less weight than L line animals, so that between the ages of 12 and 18 months there were no significant line differences in live weight. It was concluded that selection for cow fertility had not directly altered the progeny's growth rate. Tick resistance and heat tolerance also did not differ between the lines. However, resistance to worms was lower (P < 0·05) in the H line indicating genetic antagonism between cow fertility and worm resistance. Scrotal circumference and scrotal circumference adjusted for live weight were significantly higher in H line bulls between 9 and 18 months of age. Pregnancy rates of heifers in the H line were 0·12 higher than in the L line despite similar average live weights at mating. It is suggested that accelerated sexual maturity in both heifers and bulls has occurred as a result of selection for lifelong cow fertility.

Keywords

cattlefertilityselectiontropics
Type
Research Article
Information
Animal Production , Volume 50 , Issue 3 , June 1990 , pp. 417 - 424
Copyright
Copyright © British Society of Animal Science 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Baker, R. L. and Morris, C. A. 1984. A review of correlated responses to weight selection in beef cattle under different management and climatic conditions. Proceedings of 2nd World Congress on Sheep and Beef Cattle Breeding, Pretoria, South Africa, pp. 236–251.Google Scholar
Barlow, R. 1978. Biological ramifications of selection for preweaning growth in cattle. A review. Animal Breeding Abstracts 46: 469–494.Google Scholar
Brinks, J. S., McInerney, M. J. and Chernoweth, P. J. 1978. Relationship of age at puberty in heifers to reproductive traits in young bulls. Proceedings of Western Section of American Society of Animal Science 29: 28–30.Google Scholar
Dearborn, D. D., Koch, R. M., Cundiff, L. V., Gregory, K. E. and Dickerson, G. E. 1973. An analysis of reproductive traits in beef cattle. Journal of Animal Science 36: 1032–1040.CrossRefGoogle ScholarPubMed
Deese, R. E. and Koger, M. 1967. Heritability of fertility in Brahman and crossbred cattle. Journal of Animal Science 26: 984–987.CrossRefGoogle ScholarPubMed
Finney, D. J. 1941. On the distribution of a variate whose logarithm is normally distributed. Journal of the Royal Statistical Society, Supplement No. 7, pp. 155–161.Google Scholar
Frisch, J. E. 1981. Changes occurring in cattle as a consequence of selection for growth rate in a stressful environment. Journal of Agricultural Science, Cambridge 96: 23–38.CrossRefGoogle Scholar
Frisch, J. E., Munro, R. K. and O'Neill, C. J. 1987. Some factors related to calf crops of Brahman, Brahman crossbred and Hereford × Shorthorn cows in a stressful tropical environment. Animal Reproduction Science 15: 1–26.CrossRefGoogle Scholar
Hetzel, D. J. S., MacKinnon, M. J., Dixon, R. and Entwistle, K. W. 1989. Fertility in a tropical beef herd divergently selected for pregnancy rate. Animal Production 49: 73–81.Google Scholar
Keith, R. K. 1953. The differentiation of the infective larvae of some common nematode parasites of cattle. Australian Journal of Zoology 1: 223–235.CrossRefGoogle Scholar
King, R. G., Kress, D. D., Anderson, D. C, Doornbos, D. E. and Burfening, P. J. 1983. Genetic parameters in Herefords for puberty in heifers and scrotal circumference in bulls. Proceedings of Western Section of American Society of Animal Science 38: 11–13.Google Scholar
Koch, R. M., Gregory, K. E. and Cundiff, L. V. 1982. Critical analysis of selection methods and experiments in beef cattle and consequences upon selection programs applied. Proceedings of 2nd World Congress on Genetics Applied to Livestock Production, Madrid, Spain, pp. 514–526.Google Scholar
MacKinnon, M. J., Taylor, J. F. and Hetzel, D. J. S. 1990. Genetic variation and covariation in beef cow and bull fertility. Journal of Animal Science In press.CrossRefGoogle ScholarPubMed
Roberts, F. H. S. and O‘Sullivan, P. J. 1950. Methods for egg counts and larval cultures for strongyles infesting the gastro-intestinal tract of cattle. Australian Journal of Agricultural Research 1: 99–102.CrossRefGoogle Scholar
Seebeck, R. 1973. Sources of variation in the fertility of a herd of zebu, British and zebu × British cattle in Northern Australia. Journal of Agricultural Science, Cambridge 81: 253–262.CrossRefGoogle Scholar
Toelle, V. D. and Robison, O. W. 1985. Estimates of genetic correlations between testicular measurements and female reproductive traits in cattle. Journal of Animal Science 60: 89–100.CrossRefGoogle ScholarPubMed
Turner, H. G. 1982. Genetic variation of rectal temperature in cows and its relationship to fertility. Animal Production 35: 401–412.Google Scholar
Turner, H. G. and Short, A. J. 1972. Effects of field infestations of gastrointestinal helminths and of the cattle tick (Boophilus microplus) on growth of three breeds of cattle. Australian Journal of Agricultural Research 23: 177–193.CrossRefGoogle Scholar
Utech, K. B. W., Seifert, G. W. and Wharton, R. H. 1978. Breeding Australian Illawarra Shorthorn cattle for resistance to Boophilus microplus. I. Factors affecting resistance. Australian Journal of Agricultural Research 29: 411–422.CrossRefGoogle Scholar