Relationship between evaluations of sires in pale-motley cattle population at different levels of management

Abstract

Reproductive technologies have led to a wide and global distribution of genetic material from animals with high productivity. However, the distribution of semen from the same bulls to different regions (countries) may not always meet the expectations of livestock breeders. This aspect may be due to the fact that the genetic structure of the breeding stock, breeding goals and environmental conditions vary from region to region. The article presents the results of evaluating the breeding value of 286 sires used on the breeding stock of the pale-motley dairy cattle population in five regions of the Russian Federation (Belgorod, Voronezh, Kursk, Oryol regions and Altai Territory). The evaluation was carried out according to individual traits of daughters' milk productivity, and on multiple traits (selection index). Based on the results of the study, differences were identified in estimates of the breeding value of the same sires at the level of total information (population level) and in the herds of single regions (regional level). The accuracy of evaluating genotypes at the population management level was significantly higher (by 7–15 percent) than it was at regional levels. The correlations between the breeding value of the same sires at different levels of management (population-region) for single traits of daughter’s milk productivity were 0.522–0.960, for the complex of traits (selection index) – from 0.157 to 0.937. This indicates that when selecting the best sires at the level of an individual region, mistakes can reach 4–48 % for single milk productivity traits and from 6.3 to 84 % for their complex.

Keywords

• dairy cattle
• selection groups
• milk productivity traits
• blup-methodology
• selection index
• rank correlation