INFLUENCE OF PARENTS ON MILK YIELD OF SYCHEVSKAYA AND BROWN SWISS COWS BREED

Abstract

Stock breeding with domestic cattle in the Smolensk region based on generally accepted methods does not allow for effective control of the genetic processes occurring in herds. Existing approaches take into account the additive action of genes only and do not take into account dominance and epistasis, which, against the background of the non-systemic influence of the external environment, does not allow an objective assessment of the genetic contribution of ancestors into the offspring genotype. The aim of the research the influence of parents on the milk yield of daughters for the first lactation using the method of assessing the degree of parental influence (SRV) was to study. The work on a sample of 976 and 224 breed of Sychevka and Brown Swiss cows in herds of breeding farms of Smolensk region KP "Rybkowski" and SPK "Druzba" was conducted. For both breeds, it is characteristic that the daughters of mothers divided into three classes of variation series according to the degree of development of the trait, showed no significant difference in milk yield depending on the class of the mother. Within each class of mothers, there was a slight shift in the frequency of similarly distributed daughters towards the class of mothers. Fathers influenced the milk yield of their daughters, the frequency of their distribution in classes of variation series, and the qualitative change of daughters relative to mothers. The productive characteristics of mothers did not significantly affect the maximum milk yield of their daughters. None of the quality groups of bulls had an advantage in the number of best daughters.