The formation of a combined selection index in sheep breeding

Successful breeding work is impossible without qualitative evaluation of animals used in the breeding process. Only the selection of the highest rates animals is significant economically. These useful features can lead to the desired result of breeding. The simplest form of selection of animals is one sign selection. At the same time, in the modern practice breeding is carried out on several grounds. In this case, it is advisable to use selection by selection indexes. This form of animals selection is theoretically the most effective one. Index animals assessment allows to consider several economically useful signs at once. It leads to the fact that low indicators of one of the used features can be compensated by high indicators of other features. Besides, high rates of any feature can be reduced by other features low values. To avoid the situation, it is proposed to form indexes on two different bases - the basis of selection differential and the basis of selection ratio. It will not exclude from further breeding process animals with high individual characteristics. Index evaluation uses data on self-assessed productivity of animals. It is not enough for successful breeding work. Therefore, in this article it is proposed to form a combined breeding index, which takes into account not only the data on their own productivity of animals, but also their assessment of the quality of offspring. It is proposed to use the BLUP method for evaluation by offspring. The article presents an algorithm for combined breeding indexes formation. The features of index selection in fine-wool sheep breeding are considered. The use of this approach can help breeders to improve the efficiency of breeding work.