The Influence of Growth and Development Indicators of Holstein Black-and-White Young on the Productive Characteristics of Cows in the Vologda Region

The study aimed to investigate the relationship between growth and development indicators of first-calf Black-and-White Holstein cows and their subsequent milk productivity. The experiment was conducted in the Vologda Region. The sample included 583 cows, as well as the cows that were dropped from the herd in the period from 2020 to 2021. After selection, animals were divided into three groups based on milk yield during their first lactation. For each group, average birth weight and weights at 6, 10, 12, and 18 months of age were calculated. Additionally, live weight and coefficient of milk yield capacity were determined for the first, second, and third lactations. All animal groups were kept under identical feeding and housing conditions. It was found that the third group with a milk yield of 8,843-11,153 kg for the first lactation had the highest birth weight of 34.98 kg and reached the highest mature weight of 422.61 kg. Data on live weight and coefficient of milk yield capacity for three lactations showed that the cows of the third group were in the lead, their live weight ranged from 566.01 to 638.03 kg, and coefficient of milk yield capacity was from 1,465.7 to 1,661.8 kg.