The future impact of new opportunities in reproductive
physiology and molecular biology on genetic improvement programmes
R.L. Baker, P. Shannon, D.J. Garrick, H.T. Blair, B.W. Wickham
Ruakura Agricultural Centre, Ministry of Agriculture and
Fisheries
Proceedings of the New Zealand Society of Animal Production.
1990, 50: 197-210
The possible impact of developments in artificial insemination
(AI), multiple ovulation and embryo transfer (MOET), sexed semen and
embryos, cloning, physiological markers, genetic markers and transgenic
livestock on rates of genetic change are reviewed and discussed.
Previous theoretical predictions have exaggerated the potential
increases in rates of genetic change available from MOET, particularly
in small, closed MOET nucleus schemes. Sexing of semen and/or embryos
has a relatively small effect on rates of genetic change, but sex
control can potentially have a dramatic effect on the efficiency of
farming systems. Developing techniques to produce large clone families
in livestock will increase rates of genetic change, particularly through
faster dissemination of superior genotypes to commercial populations. A
cost-benefit analysis of some different strategies for increasing
genetic change in the New Zealand dairy cattle population has identified
that useful contributions could come from AI (by doubling current bull
coverage) and from MOET and genetic and/or physiological markers.
Equally important economic returns were identified from increasing the
number of bull mothers continuously bred by AI.
The impact of transgenic animals, gene mapping and genetic markers
(linkage) on rates of genetic change is likely to take much longer (10-
20 years) than the reproductive techniques.
Keywords: NZSAPAB;
Genetic gain; artificial insemination; multiple ovulation and
embryo transfer; cloning; genetic markers; transgenics
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Last Updated 25-01-1997
