Relative Variability of Breeding Traits of the Dairy Cattle and the Breeding Process

Natalya Shevchuk, Zhanna Ignatenko, Tetiana Pidpala, Elena Petrova

Abstract: The relative variability of multifactorial traits of the productivity and reproductive capacity of dairy cattle through different selection methods during the breeding process. Breeding for increasing milk fat in the first stages of the genesis of the Ukrainian Red Dairy Breed caused a change in the correlation between milk yield and fat content in milk from negative (r = -0.20; p < 0.001) to positive (r = +0.07), and in the fifth stage of breeding, a negative link was established (r = -0.31; p < 0.001). This was due to a change in the direction of breeding, namely the reduction of pressure on the basis of “fat content in milk” and the intensive selection to increase the milk yield of animals of the Holstein gene pool breed. A high negative correlation between milking and the coefficient of reproductive ability in the study animals of stage V is natural (r = -0.78; p < 0.001). According to different selection methods, there is a general tendency for a positive correlation between milk yield and milk fat content, and a weak negative correlation exists between milk yield and fat content. A regular change in the correlation relationships of breeding traits occurring under the influence of the breed formation process has been proved. In certain periods of the genesis of the breed, the power of negative correlation between milk yield, milk fat content, and reproductive capacity increases. With increasing heterogeneity of selection, the strength of the link between performance traits and reproductive capacity increases. It has been established that the breeding formation process and selection methods cause significant restructuring of correlation relationships between the traits of productivity and the reproductive capacity of dairy cattle, and their change can be predicted according to the established patterns of relative variability and thus purposefully manage the breeding process.

Keywords: Keywords: cattle, breeding formation process, selection, trait, correlation

Date published: 2020-06-06