Influence of outbreeding and inbreeding on milk productivity of the Kostroma breed cows

Abstract

The material about modern genealogical structure of the Kostroma breed of cattle, breeding base and kinship relations of cows in the breeding farms of the Kostroma region is presented. Domestic Kostroma breed of cattle, possessing valuable economically useful qualities, accounts for 33.5% in the region. The studies were conducted in three breeding farms and two pedigree breeding units in 2023. Breeding and zootechnical records data were used as the research material. The research methods are zootechnical, population-genetic and analytical with the use of computer programs. Milk productivity of cows at outbreeding (unrelated breeding) and at different degrees of kinship at inbreeding was analyzed separately for all breeding plants and pedigree breeding units in the Kostroma region. Out of 1736 cows of the Kostroma breed studied, 918 (52.9%) were obtained by outbreeding, 818 (47.1%) by inbreeding, including distant – 461 (26.5%), moderate – 310 (17.8%), close – 41 (2.4%) and consanguinity – 6 (0.4%). Outbreeding and distant and moderate inbreeding were mostly used in breeding farms. The level of spontaneous inbreeding was 2.8%. Higher milk yields are inherent to outbred cows from all breeding farms of the Kostroma region, fat and protein content in milk - to outbred cows and the animals with different degrees of inbreeding in the conditions of specific farms. The results of the research indicate higher milk productivity of the cows under outbreeding. The obtained data were used for making plans of selection and breeding work with the Kostroma breed of cattle in breeding farms.