Evaluation of Black Pied first-calf heifers` lactation of various genotypes
Purpose: Comparative assessment of the fullness of lactation of primarmels of different genotypes.Materials and methods. The article presents the results of the assessment of the lactation activities, which was carried out in the SEC "Kazminsky" Kochubeevsky district of the Stavropol region on the livestock of the black and motley breed of local and brown populations from the Vologda region from LLC "Zaozerier" (farm №. 1) and SHPK "Proseukhon" (farm №2). Three experienced animals groups of 30 goals were formed in each, studies were carried out according to generally accepted methods.Results. The greatest amount of milk for 305 days I lactation was obtained from the first elevations brought from LLC "Zaozerier" - 7368 kg, which is 3.64% more than from the cows of their own reproduction and 8.85% more than from animals grown in SEC "Proseukhonskoye". The lactation stability ratio was calculated in two ways, and in both cases there was more than 100, the factor of the fullness of lactation in the cows of the studied genotypes this indicator was also very high and amounted to 87.7-91.6, which indicates a high level of breeding and tribal work, and On the significant influence of genetic factors on the lactation activity of the studied animals. According to the nature of the lactation curve, the pilot of all three genotypes can be attributed to the I type - high stable lactation. However, the greatest amount of milk from cows was obtained in the third phase of lactation.Conclusion. Thus, it can be concluded that the period of adaptation did not have a significant impact on the lactation activity of the delivered first elements. The animals studied were characterized by high productivity and sustainable lactation.It is desirable when evaluating the cows, along with productivity for 305 days of lactation, consider individual qualities and the ability to hold high productivity to a large part of the lactation period. For more differentiated selection of cows in the breeding group, we recommend using the stability coefficients and the usefulness of lactation.