Genetic and phenotypic correlations for some characteristics of pure-bred dairy cows of the Simmental breed

The article presents the results of research on the assessment of genetic and phenotypic correlations of reproductive and dairy qualities of pure-bred dairy cows of the Simmental breed in JSC "Komsomolets" breeding plant of the Tambov region. Data were collected over the last 13 years (2006-2019) for 1,663 calves and 1,420 lactation. The values of genetic and phenotypic correlation for reproductive and dairy traits were evaluated using the SAS System Software two-dimensional analysis. Direct genetic and phenotypic correlations for reproductive and dairy traits were evaluated on the basis of a two-dimensional animal model taking into account two traits simultaneously. Genetic correlations between reproductive traits ranged from -0.11±0.01 to 0.98±0.10, while the values of phenotypic correlation ranged from 0.04±0.03 to 0.97±0.01. For signs of dairy productivity, genetic correlations ranged from 0.91±0.20 to 0.96±0.06, while the values of phenotypic correlation ranged from -0.04±0.03 to 0.80±0.02. Direct genetic correlations between reproductive and dairy traits ranged from -0.87 to 0.98, while phenotypic correlation values ranged from -0.01±0.03 to 0.44±0.03. Positive direct genetic correlations between traits showed that choosing one trait can improve another trait. The correlation between reproductive and dairy qualities should be taken into account when selecting and developing a program for genetic improvement of dairy cattle. Selection by age at the first insemination and the dry-hardy period will be important for increasing the productivity of pure-bred cows of the Simmental breed.