Abstract

If the phenotypic and genetic parameters of two strains are of the same magnitudes, the derived selection indices, based on the Smith-Hazel's method, of the two strains must be the same, regardless of their levels of performance. To reflect such a difference in production levels of these strains, one must modify the relative economical weights according to the .breeder's preference. Such modifications have no justification, however. Yamada et al.(1975) reported the method of constructing a selection index when gains of individual traits are primary concern of the breeder. The idea was arisen to filfull the desire of breeders dealing with several strains which differed in the level of production in various economically important traits. The index is now widely used in both animal and plant breeding.

Y. Yamada, M. Naito

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume 8. Symposia (2), , 808-812, 1982