Effectiveness of breeding work with families of Holstein cattle in the SPK PZ «Detskoselsky» of the Leningrad region

Purpose : to analyze the productive qualities of the leading families of Holstein cattle of the SPK PZ «Detskoselsky» of the Leningrad region. Materials and methods . The object of research was black-and-white Holstein cows in the amount of 1,425 heads. In order to ensure the representativeness of the data, animals belonging to a family consisting of at least 15 cows were selected from the entire livestock, the best families were selected according to milk productivity (milk yield, fat content in milk). Thus, the sample consisted of 456 cows belonging to 17 families. The research material was the cards of breeding cows (F2-MOL), data from the breeding and primary zootechnical accounting of the IAS "Selex" SPK PZ "Detskoselsky" in the period from 2021 to 2023. The calculation of breeding and genetic parameters was carried out according to standard methods (N.A. Plokhinsky, 1970, E.K. Merkuryeva 1970) using modern computer technology using the MS EXCEL analysis package. Results . As a result of the analysis of milk productivity for the first and last completed lactation of cows belonging to the leading families, the best milk productivity indicators were revealed (milk yield, fat and protein content in %, milk fat and protein yield in kg). The selection and genetic parameters characterizing the dairy productivity of cows of the leading families are calculated. Conclusion . The selection and breeding work carried out with families in the conditions of the SPK PZ «Detskoselsky» has positive results. In order to further improve the breeding and productive qualities of animals, it is necessary, along with line breeding, to continue working with families, intensively use the most productive ones for offspring – Ag'e 16, Barka 34, Bozhayu 28, Bravaya 49, Vervahting 61, Viktoriya 67, Gulena/Gulla 78/171, Lyura 134/136, Majka 150 and Teres 221 and also create new even more productive families.