Influence of genotypic factors on duration of economic use of black and pestre cows in Udmurtia

The analysis of the influence of genotypic factors, including the linear belonging of cows and the characteristics of bulls of producers, is carried out. According to the results of the research, it is established that in the herd of 4075 cows, 51.46% of cows are in the line of VB. Idyl, 27.9% of cows R.Sovering, 14.7% of cows M. Chiftein, 5.94% S.T. Rokyt. The greatest lifespan was observed in the cows of the M. Chiftein line - 85.9 months, which is 26.9% more than in the cows of the R. Sovering line (P> 0.999), 15% more than the cows of the S.T. Rokyt (P>0.999), 11.1% more than V.B. Idyl (P>0.999). Analyzing the indicators characterizing the age of animals and the indicators characterizing the productive qualities of the daughters of used bulls of producers in this breeding enterprise,it was found that the cows-daughters of the bull have the largest lifelong milk yield in the herd. The bull Opyt was 8748-26045.1 kg, which is 27.3 % above the average value for the herd (P>0.999). The smallest lifelong milk yield in the herd is produced by the bull Cascade 6021 - 12292.1 kg, which is 35% below the average value for the herd (P>0.999). Thus, the obtained results on the study of genotypic factors affecting the productive longevity of cows give an objective picture for the formation of a further strategy for breeding cattle with the aim of increasing the time of economic use of cows and obtaining greater productivity.