Dairy productivity of cows of the first lactation of different breeding under conditions of industrial milk production

Abstract

Relevance . The dairy productivity of first-calf cows depends on many factors, including their origin. In breeding cattle, it is necessary to take into account the linear affiliation of the daughters of bulls of different origins. Breeding enterprises of the Leningrad region specialize in the cultivation of Holstein cattle, characterized by high dairy productivity. The purpose of the research is to evaluate the milk productivity of Holstein cows of different origins after their first lactation. Methods . The object of the study was cows of the Holstein breed (915 heads) of the lines Vis Back Ideal 1013415 (339 heads) and Reflection Sowering 198998 (576 heads) with completed first lactation. Research materials are data from zootechnical and breeding records for the period of scientific and economic experience. According to the data of monthly control milking, a comparative analysis of dairy productivity of cows by milk yield for 100, 200 and 305 days of lactation, the mass fraction of fat and protein in milk was carried out. According to the generally accepted method, the amount of milk fat and protein is calculated.  Results . It was found that during lactation, individuals of different lines produced milk with different intensities. Thus, during the breeding period, cows of the Reflection Sowering 198998 line surpassed their peers in milk yield by 3.6%, 200 days of lactation — 3.5%, 305 days — 5.2%, for the whole lactation the difference was 5.5%. Differences between the groups of the studied animals on the qualitative composition of milk were insignificant, and the existing fluctuations in the content of fat and protein in milk during lactation were caused by the regularities of lactation activity of cows. The origin of cows from outstanding breeding bulls has a significant impact on the dairy productivity of first-calf cows, which is taken into account in breeding work with the herd. The highest milk yield for lactation was obtained from the daughters of the bulls of the Vis Back Ideal 1013415 Salute 1250 and Silver 1214 (10352-10372 kg) line, as well as the Reflection Sowering 198998 — Alta Instance 11747 and Napoleon 9840 (10256-10274 kg) line. This allows us to recommend the listed bulls in breeding and breeding work with the Holstein breed in the herd of a breeding enterprise in the direction of increasing the dairy productivity of livestock and improving the quality of milk.