Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-23T01:56:42.486Z Has data issue: false hasContentIssue false
  • English
  • Français

The importance of family sizes in adult multiple ovulation and embryo transfer (MOET) nucleus breeding schemes in dairy cattle

Published online by Cambridge University Press:  02 September 2010

J. Ruane
J. Ruane
Affiliation:
AFRC Institute of Animal Physiology and Genetics Research, Roslin, Midlothian EH25 9PS‡
Get access

Abstract

The importance of family sizes in adult multiple ovulation and embryo transfer (MOET) nucleus schemes with discrete generations of single trait selection was examined using Monte Carlo simulation. Two areas were investigated. Firstly, the number of sons and daughters per dam was varied in schemes using hierarchical mating designs. With four or eight sires and 32 dams selected, increasing the number of sons per dam from one up to four achieved 1 to 8% higher rates of response but at the expense of increased variation in response and 10 to 56% higher rates of inbreeding. With four or eight sires and 16, 32 or 64 dams selected, the number of daughters was set to two, four or eight (with one son per dam in each case). For schemes transferring equal numbers of embryos, responses were lower with two daughters per dam but were fairly similar with four or eight daughters per dam while inbreeding rates increased as fewer sires and dams were selected. Secondly, the effects of variation in family sizes due to biological factors and chance were investigated with eight sires and 32 dams selected and with hierarchical or factorial (two or four sires per dam) mating designs. When all selected cows yielded embryos, changes in family sizes due to differences in sex ratios, in survival rates of embryos to selection and to variation in the number of embryos per donor reduced response by 1 to 4%. However, when 20% or 33% of the superovulated females yielded no embryos, thus requiring the use of genetically inferior replacements, response was reduced by a further 9 to 13%

Keywords

breeding programmesdairy cattleembryo transfergenetic gain
Type
Research Article
Information
Animal Production , Volume 52 , Issue 1 , February 1991 , pp. 33 - 47
Copyright
Copyright © British Society of Animal Science 1991

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

Becker, W. A. 1975. Manual of Quantitative Genetics. 3rd ed. Washington State University, Pullman, Washington.Google Scholar
Bulmer, M. G. 1980. The Mathematical Theory of Quantitative Genetics. Clarendon Press, Oxford.Google Scholar
Falconer, D. S. 1981. Introduction to Quantitative Genetics. 2nd ed. Longman, London.Google Scholar
Hahn, J. 1989. Superovulation, embryo transfer, cryopreservation and sexing of embryos. In New Selection Schemes in Cattle: Nucleus Programmes (comp, Kalm, E. and Liboriussen, T.), pp. 5–14. Pudoc, Wagenigen.Google Scholar
Hill, W. G. 1976. Order statistics of correlated variables and implications in genetic programmes. Biometrics 32: 889–902.CrossRefGoogle Scholar
Jansen, G. and Schlote, W. 1987. Variability of genetic progress using multiple ovulation and embryo transfer in small nucleus herds of cattle. Proceedings of the Symposium of Biotechnology in Animal Breeding (ed. Weniger, J. H., Horst, P. and Iritani, A.), pp. 170–180. Technical University of Berlin, West Germany.Google Scholar
Juga, J. and Maki-Tanila, A. 1987. Genetic change in a nucleus breeding dairy herd using embryo transfer. Ada Agriculturae Scandinavica 37: 511–519.CrossRefGoogle Scholar
Nicholas, F. W. and Smith, C. 1983. Increased rates of genetic change in dairy cattle by embryo transfer and splitting. Animal Production 36: 341–353.Google Scholar
Ruane, J. 1991. The effect of alternative mating designs and selection strategies on adult multiple ovulation and embryo transfer (MOET) nucleus breeding schemes in dairy cattle. Genetics Selection Evolution In press.Google Scholar
Ruane, J. and Thompson, R. 1991. Comparison of simulated and theoretical results in adult MOET nucleus schemes for dairy cattle. Livestock Production Science In press.Google Scholar
Schaeffer, L. R. and Kennedy, B. W. 1986. Computing strategies for solving mixed model equations. Journal of Dairy Science 69: 575–579.CrossRefGoogle Scholar
Seidel, G. E. 1984. Applications of embryo transfer and related technologies to cattle. Journal of Dairy Science 67: 2786–2796.CrossRefGoogle ScholarPubMed
Woolliams, J. A. and Wilmut, I. 1989. Embryo manipulation in cattle breeding and production. Animal Production 48: 3–30.CrossRefGoogle Scholar