Influence of the age of the first insemination on the productive longevity of cows

The article presents the results of a study of the influence of the age of the 1st insemination of holstinized heifers on the milk productivity and productive longevity of cows. In general, over the past 13 years, a pronounced tendency has been observed in the studied herd to reduce the age of the 1st insemination by 3.5 months. Studies showed that the average age of abandonment of animals is positively associated with the age of the 1st insemination, i.e. the higher the average age of the 1st insemination of heifers, the higher the average age of abandonment (IOS) of cows, i.e. higher productive longevity of animals. Live weight and average daily growth of heifers inseminated at the age of 12 months. were noticeably higher than others. Analysis of the milk productivity of first-calf cows showed that among animals of all groups, in general, animals inseminated in 14 and 15 months turned out to be somewhat more productive. Studies have established that there is a negative relationship between the age of the 1st insemination and the age of manifestation of maximum milk yield of cows: the earlier the heifer is inseminated, the later it shows maximum productivity. At the optimal age of the 1st insemination, a cow can lactate in a herd of at least 3 lactation. Reducing the age of the 1st insemination leads to a reduction in productive longevity. In order to increase productive longevity in the conditions of this farm, it is not recommended to inseminate heifers earlier than 14 months.