the effect of improved reproductive performance on genetic gain and inbreeding in moet breeding schemes for beef cattle改善繁殖性能的影响遗传增益和近亲繁殖在酩悦肉牛育种方案.pdf

Original article The effect of improved reproductive performance on genetic gain and inbreeding in MOET breeding schemes for beef cattle B Villanueva JA Woolliams G Simm Scottish1 West Mains Road, EH9 ,!JG; Agricultural College, Edinburgh, Roslin2Institute (Edinburgh), Roslin, Midlothian, EH25 9PS, UK (Received 9 November 1994; accepted 6 March 1995) Summary - The effect of improved reproductive techniques on genetic progress and inbreeding was investigated in MOET (multiple ovulation and embryo transfer) schemes for beef cattle. Stochastic simulation was used to model a closed scheme with overlapping generations. Selection was on a trait measured in both sexes, with heritability 0.35, and was carried out for 25 years. The number of breeding animals was 9 sires and 18 donors. Embryo production was modelled using a Poisson distribution with the parameter distributed to a distribution. The mean number of transferable flush according gamma embryos per and per donor was 5.0, with a coefficient of variation of 1.28 and repeatability between flushes of 0.22. This model was compared with models used in previous studies (fixed number of flush or variable number of but with zero embryos per embryos repeatability between flushes). The coefficient of variation and the repeatability of embryo yield influenced inbreeding rates. The rate of inbreeding was underestimated by up to 17% when variability of embryo production was ignored. Without a constraint on the number of calves born per year, i