Publisher : Asian Australasian Association of Animal Production Societies
DOI : 10.5713/ajas.2002.1686
Title & Authors
Relationships between Distribution of Number of Transferable Embryos and Inbreeding Coefficient in a MOET Dairy Cattle Population Terawaki, Y.; Asada, Y.;
Genetic gains and inbreeding coefficients in a Holstein MOET breeding population were predicted under different conditions relating to the distribution of the number of transferable embryos collected per flush using Monte Carlo simulation. The numbers of transferable embryos collected per flush were determined using five distributions (distributions 1, 3, 5, 7 and 9) with different aspects and similar means. Distributions 1, 3, 5, 7 and 9 were assumed to have gamma distribution's parameters ( and ) of (1 and 4.4), (3 and 1.47), (5 and 0.88), (7 and 0.63) and (9 and 0.49), respectively. Inbreeding rates were statistically significantly different among distributions but genetic gains were not. Relationships between inbreeding rates and variances of family size could be were clearly distinguished. The highest inbreeding coefficients were predicted in distribution 1 with the largest variance of family size, while distributions 5, 7 and 9 with smaller variance of family size had lower inbreeding coefficients.
Asada, Y. and Y. Terawaki. 2000. Adaptation of distribution on number of transferable embryos per treatment. Anim. Sci. and Agric. Hokkaido. 42:418-426.
Asada, Y. and Y. Terawaki. 2001. Estimation of heritability and repeatability for superovulatory responses of Japanese Holstein population. J. Dairy Sci. 8 (Supp. 1) 109(Abstr.).
Asada, Y. and Y. Terawaki. 2002. Heritability and repeatability of superovulatory responses in Holstein population in Hokkaido, Japan. Asian-Aust. J. Anim. Sci. 15:944-948.
Falconer, D. S. and T. F. Mackay. 1989. Introduction to quantitative genetics. 4th Ed. Addison Wesley Longman Limited, Harlow, England.
Keller, D. S. and G. Teepker. 1990. Effect of variability in response to superovulation on donor cow selection differentials in nucleus breeding schemes. J. Dairy Sci. 73:549-554.
Leitch, H. W., C. Smith, E. B. Bernside and M. Quinton. 1995. Effects of female reproductive rate and mating design on genetic response and inbreeding in closed nucleus dairy herds. Anim. Sci. 60:389-400.
Nicholas, F. W. and C. Smith. 1983. Increased rates of genetic change in dairy cattle by embryo transfer and splitting. Anim. Prod. 36:341-353.
SAS Institute Inc. 1988. SAS/STAT User's Guide: Version 6. 1st edn. (Japanese). SAS Institute Inc., Cary, North Carolina.
Terawaki, Y. and Y. Asada. 2001a. Effects of different methods for determining the number of transferable embryos on genetic gain and inbreeding coefficient in a Japanese Holstein MOET breeding population. Asian-Aust. J. Anim. Sci. 14:597-602.
Terawaki, Y. and Y. Asada. 2001b. The relationship between the estrous situation of donor cows and genetic gain in Japanese Holstein MOET populations. J. Dairy Sci. 84(Supp. 1):411 (Abstr.).
Villanueva, B., J. A. Woolliams and G. Simm. 1995. The effect of improved reproductive performance on genetic gain and inbreeding in MOET breeding schemes for beef cattle. Genet. Sel. Evol. 27:347-363.
Woolliams, J. A., Z. W. Luo, B. Villanueva, D. Waddington, P. J. Brodbent, W. A. C. Mckelvey and J. J. Robinson. 1995. Analysis of factors affecting superovulatory responses in ruminants. J. Agric. Sci. 124:61-70.