The correlations between selection traits of cows in different lines Holstein breed

The article is devoted to the study of the economic and biological traits of first-calf cows of the Holstein breed of various linear affiliation. The article presents data on the correlation analysis of productivity indicators in the herd of Holstein cows in the Orel region. The correlation of milk yield for 305 days and the fat content in milk, the protein content in milk, live weight were studied. It was determined that the greatest correlation in the herd was observed between milk yield for 305 days of lactation and the mass fraction of protein. The greatest correlation between milk yield for 305 days of lactation - fat mass fraction and milk yield for 305 days of lactation-protein mass fraction in the lines of Holstein first-born Chicks was observed in the line W.B. Ideal 1013415, and for milk yield for 305 days of lactation-live weight in the line R. Sovereign 198998. The variability of milk yield for 305 days in different lines was 9.35-13.04%, the variability of milk fat content was 1.53-2.36%, and the variability of protein content in milk was 0.41-0.85%. The studies have shown that the best line in the herd of Holstein cows was the line of W.B. Ideal 1013415. According to the results of the studies, it is recommended to carry out selection work based on this line.