Level of milk productivity in Holstein cows of different ages within intensive milk production technology

Abstract

The level of milk productivity in cows and intensity of herd reproduction, which is functionally dependent on it, are the most important components of the integrated value of the volume and efficiency of milk production, both in a separate farm or industrial complex and at the regional level. Special feature of dairy cattle breeding is that the production of the main product and reproduction of productive livestock is carried out at the expense of the parent herd. Therefore, studying cows’ productive longevity and reducing the herd restoring percentage is a very urgent problem. The study was conducted on the basis of the dairy complex for the milk production by Holstein cows of the private joint-stock company «Agro-Soyuz» of Dnipropetrovsk region. Manifestation level of the genetic milk productivity potential of highly productive Holstein cows from the first to the fourth lactation (1st, 2nd, 3rd, 4th experimental groups) under the conditions of intensive milk production technology was determined. It includes three times daily milking (two times before the beginning of dry period), absence of active exercise; rest in the box where sand acts as a litter; stimulation of heat period and synchronization of ovulation, starting from day 17 after calving according to the «Ovsynch» scheme; dry period starts from 234 days of pregnancy. It was found that the maximum manifestation of the milk productivity genetic potential for full lactation in the first-calf cow is 15 632 kg of physical milk, while this indicator in animals of other experimental groups did not rise to 14 000 kg of milk. The functional activity of the body was determined by the maximum daily milk yield and milk productivity coefficient. The highest daily milk yields were shown by the cows of the second lactation, while the maximum milk productivity coefficient was in animals of the first lactation. Cows of 3rd and 4th groups in terms of milk productivity coefficients were inferior to the first-calf cows by 4.5 and 3.5 kg, respectively. The milk fat content in cows from the first to the third lactation did not decrease below 3.8 %, but in the technologically depleted cows of 4th group this indicator decreased to the level of 3.79 %. In cows of the first three lactations, production was characterized by a sufficient level of milk protein content – 3.22 %, while animals of 4th group were inferior to younger ones by 0.04 % in terms of milk protein content.

Keywords

• cow
• milk yield
• milk productivity coefficient
• milk fat
• milk protein