Characteristics of cow families, considering the level of their yields and breeding value

Abstract

Effective inbreeding selection, which includes family breeding, is an important task of our time, since the presence of valuable families characterizes the degree of breeding of the herd and the level of breeding work in it. Therefore, the aim of our study was to carry out a retrospective analysis of data of zootechnical accounting for dairy performance and breeding value of 17 families with high-performance in the LCC "Veleten" herd, created by absorption crossing of Ukrainian Black-and-White dairy cow with Holstein breeders. It was established that controlled families were characterized by a significant level of differentiation by content of milk yield, fat and protein in milk. The best by yields it was appeared to be family of Gita UA5900293739, by fat content Soroka UA5900397448 family, and by protein content Koldunya UA5900066978 family. Objective evaluation of a family can be done only when considered breeding value and ancestors, daughters, granddaughters, great-granddaughters, etc. Duna UA5900379687 was the best by breeding value for yield, quantity of milk fat and milk protein the family, Soroka UA5900397448 by fat content in milk and Koldunya UA5900066978 by protein content in milk. The nature of changes in indices of breeding values in generations under the control 12 belonged to category of progressive, 4 – to a stable and just 1 – to regressing. Objective evaluation of a family can be done only when considered breeding value ancestors and daughters, granddaughters, great-granddaughters, etc. Duna family UA5900379687 was the best by breeding value for yield, quantity of milk fat and milk protein, Soroka family UA5900397448 – by fat content in milk and Koldunya UA5900066978 by protein content in milk. The nature of changes in indices of breeding values in generations under the control 12 belonged to category of progressive, 4 – to a stable and just 1 – to regressing. Correlation and regression coefficients between milk productivity features of cows-ancestors and their descendants, as well as the coefficients of heredity of the studied features were low and in almost all cases unreliable. In addition, the inheritance of fat and protein in milk was lower than inheritance of milk yields.