Changes in the live weight of cows with age and its impact on their productive qualities

In the Sverdlovsk region, holstinized black-and-white cattle of the Ural type is bred, which is represented by large, highly productive animals with a high genetic potential for productivity. The purpose of the work is to study the dynamics of live weight of cows with age and its relationship with milk productivity. In animals, there is an increase in live weight with age by 22.6 kg (from 3 to 4 lactation) – 46.2 kg (from the first to the 2 lactation) or by 3.4 – 7.9%. With an increase in live weight, there was an increase in milk yields up to 3 lactation, and then their decrease. The greatest decrease was observed in the fifth lactation. The coefficient of milk production decreases with the age of cows and is accompanied by an increase in live weight. Despite an increase in live weight and a decrease in milk yield for every 100 kg of live weight of cows, all of them turned out to be of dairy-oriented productivity. However, it should be noted that achieving a live weight of 710 kg or more leads to a decrease in the efficiency of cow use. There is a low negative relationship between live weight and milk yield of cows.