[Nucleus herds and embryo transfer for goat breeding?]
1996
Wyler, A. (ETHZ-Zentrum, Zurich (Switzerland). Institut fuer Nutztierwissenschaften, Zuechtungsbiologie) | Stranzinger, G. | Graser, H.-U.
Adult nucleus schemes with overlapping generations for goats were simulated using hierarchical mating and 256 kiddings per year. The simulated heritabilities for one or two sex-linked traits were 0.25 and 0.5. Selection was performed on breeding values estimated by an individual animal model. Four to 16 sires and 32 to 128 dams were selected each year. Accordingly, progeny per dam varied from 8 (very successful MOET) to 2 (natural breeding) in order to obtain 256 kiddings per year. The optimum of sires to maximise genetic progress was 8. Genetic progress increased by 12.6 % if the number of dams was reduced from 128 to 64 and by 7.5 % if reduced from 64 to 32. Increasing the heritability from 0.25 to 0.5 increased the genetic progress by 15 %. Reducing the number of dams increases the variance of genetic progress and therefore the risk, whereas increasing the heritability reduces the variance of genetic progress and therefore the risk. By reducing the number of parents the rate of inbreeding increases dramatically. Increasing the heritability, e.g. by decreasing environmental variance, might be competitive with MOET as a breeding strategy
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