The influence of genetic and environmental factors on the productive traits of Holstein cattle in the Orel region

The aim of the research was to study the ratio of the genetic and environmental variability of the productive traits in Holstein cattle. The studies were conducted on animals of European origin in the Orel Region. It was found that with a total variation in live weight of 2.41 kg (σ) at the time of birth, the genotypic and environmental variability of this trait in heifers was 2.07 and 0.34 kg, respectively. At 18 months, with a total variability of 33.70 kg (σ), these indicators were 29.01 and 4.69 kg of live weight. The animals of the R. Sovereign line had a 0.2 to 0.9% less phenotypic variability of live weight in all periods of growth. It was found that the herd had average heritability coefficients for the most economically significant breeding traits relating to milk productivity (h2 from +0.164 to +0.289). There were no significant heritability differences between the lines. The herd genotypic variability in milk yield for a 305 days lactation period (n = 891) was 350.2 kg, and the environmental one was 861.5 kg of milk. In terms of milk flow rate of the lines, Sigma (σ) was 0.11-0.18 kg/min (or 5.4-8.4%). The M. Chieftain line significantly exceeded the average herd indices by 2.4% of the total phenotypic variability and the trait itself by 0.061 kg/min (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }