Publisher : Asian Australasian Association of Animal Production Societies
DOI : 10.5713/ajas.2002.767
Title & Authors
The Effect of Sub-division (Two or Three Sub-populations) of a Population on Genetic Gain and Genetic Diversity Oikawa, T.; Matsui, H.; Sato, K.;
Breeding efficiencies were compared among three population schemes: a single population, a population with two subpopulations and a population with three sub-populations. A simulation experiment of selection was carried out for 10 generations with 20 replications each by comparing average breeding values and inbreeding coefficients among the three population schemes. Phenotypes of three traits were generated with a model comprising 36 loci, each with additive genetic effects and residuals distributed normally. Among the three population schemes, the single population scheme was definitely superior to the other two with regards to selection response and inbreeding. The multiple sub-population scheme was, however, considered to be an alternative population scheme when the difference in economic weights of the traits was small among the sub-populations, assuming moderate inbreeding depression for traits and crossbreeding. The scheme with two sub-populations had a higher genetic value than that with three subpopulations; however, the genetic values of the schemes were comparable when maternal heterosis was taken into account. The choice of population schemes may depend on the cost-sharing policy between the breeding population and the commercial population rather than just the breeding efficiency.
Cameron, N. D. 1997. Selection indices and prediction of genetic merit in animal breeding. 103-105. CAB International. Wallingford. UK.
Falconer, D. S. 1989. Introduction to quantitative genetics (3rd Ed.). 248-253. Longman, London. UK.
Hazel, L. N. 1943. The genetic basis for constructing selection indexes. Genetics 28:476-490.
Lynch, M. 1991. The genetic interpretation of inbreeding depression and outbreeding depression. Evolution 45:622-629.
Oikawa, T., Y. Matsura and K. Sato. 1997. Comparison of breeding system between single and two sub-population scheme by computer simulation I. Equal genetic level for subpopulations. Asian-Aus. J. Anim. Sci. 10:422-427.
Quinton, M., C. Smith and M. E. Goddard. 1992. Comparison of selection methods at the same level of inbreeding. J. Anim. Sci. 70:1060-1067.
Smith, C. and G. Banos. 1991. Selection within and across populations in livestock improvement. J. Anim. Sci. 69:2387-2394.
Smith, C. and M. Quinton. 1993. The effect of selection in sublines and crossing on genetic response and inbreeding. J. Anim. Sci. 71:2631-2638.