THE FORMATION OF SELECTION INDICES FOR PREDICTING THE EFFECTIVENESS OF SELECTION IN SHEEP BREEDING

Abstract

The quarantee to successful breeding work is the selection of animals with the best indices of significant economically useful traits. The selection of animals on any one trait does not represent any special difficulties. At the same time, in modern practice of pedigree breeding, selection is carried out on a number of traits. In this case, selection by selection indices can be used. The essence of such selection is that the selection process does not exclude animals that have a low level of development of one trait at a high value of others. The selection index is the sum of the weight coefficients products determined by the inheritability of the trait, as well as its genotypic variability, and the basis of the index. The article deals with two approaches to the formation of breeding indices that differ in the mathematical relations taken as the basis. One approach assumes the use of selection differential as the basis of the index, and the other, the selection ratio. It was shown that for a more accurate assessment of animals, the use of any one selection index is not enough. In this case, can be excluded from the further breeding process animals with high indices only on certain characteristics. The presented method for the formation of breeding indices involves additional input of weight coefficients at the discretion of the breeder. This approach allows us to identify the best individuals from the already selected group of animals with high values of selection indices. The article presents the expressions used in the formation of selection indices with different bases. Also, the article is provided with diagrams with the calculation results of selection indices.