Reproduction traits of Simmental cows obtained from sires of local and imported lines

The modern population of the Simmental breed in Russia is represented by different genotypes, and further breeding work is focused on obtaining animals mainly of dairy and meat direction of productivity using both domestic and imported sires of German and Austrian breeding. The combination of high milk productivity and good reproductive function of cows is an important criterion in breeding work with dairy cattle in general and in assessing their breeding value. Daughters born from Simmental bulls of local origin reach the age of fruitful insemination later (the age of the 1st calving is 32.5 months) and have a significantly shorter service period and intercalving period - 134.1 and 413 days, respectively, on average for three lactations, relative to the daughters from sires of Holstein lines and German-Austrian lines of imported origin. The value of the service period decreases with age regardless of the type of breeding orientation of the line: for the 1st lactation - 139.6...161.1 days, for the 2nd lactation – 131.3...148.7, for the 3rd lactation – 122.4...146.9 days. The study of indicators characterizing the reproductive function of Simmental cows obtained from local and imported breeding sires is an important aspect for evaluating and optimizing breeding work and allows us to determine the influence of the genotype of fathers on the reproductive potential of daughters.