The black-and-white cattle breeding results when using the potential of Holstein breed

The share of genes of Holstein breed was 76.8% in the herd. It was found that during the research period, the normal distributions of milk productivity traits were observed in the herd. The number of cows in the herd decreased, but their breeding qualities increased. The main reason for which animals were culled from the herd was their gynecological diseases (in some years, up to 175 to 188 heads were culled). The protein content in milk varied from 2.90 to 3.39%. Most cows produced milk in which the protein content was at a level of 3.00 to 3.19%. The herd showed positive correlations between the yields of mothers and daughters for the 305-day-long period: 0.234 for the whole herd, 0.517 for the group of cows with 50% of Holstein breed (HF) genes, 0.098 for the group with 51-75% of HF genes, and 0,189 for the group with minimum 76% of HF genes. For the herd, the heritability coefficient for milk yield for the 305-day-long period (h2) was 0.468. The percent of the protein content in milk produced by cows with 50% of Holstein genes had a high heritability coefficient of 0.668. Only cows of the M. Chieftain line showed positive correlations between the fat content in milk produced by mothers and daughters, and positive correlations between the protein content in milk produced by cows of the W. B. Ideal and M. Chieftain lines was found. With an increase in percent of Holstein breed genes (HF) from 25 to 75% and more, there were no significant differences in milk yield among first-calf cows (they amounted to 5,424 ± 83 - 5,520 ± 116 kg of milk). The percentage of fat and protein in milk for the whole herd was positively interconnected (r = + 0.460). On average, daughters exceeded their mothers by 23.3% in terms of milk yield and by 2.0% in terms of the percentage of fat content in milk (of the trait value). The quantity of milk fat and protein increased by 25.8 and 22.5%, respectively. Based on the research results, it has been concluded that the Holstein breed has a positive effect on the productive traits of dairy cattle, but technology optimization is required to continue selection activities.