Characteristics of dairy productivity and qualitative composition of milk in Holstein cattle with different genotypes of lactoferrine gene (LTF)

The genotyping of Holstein cattle by the locus of the gene LTF - EcoR I showed that the frequency of alleles and genotypes is as follows: А - 0.84 and В - 0.16; АА - 67.5% and АВ -32.5%. Differences in milk production associated with the LTF gene polymorphism were not revealed, as they obtained data are statistically insignificant. Evaluation of butter-fat yielding capacity showed that there is a decline in individuals of both genotypes and the average herd from first to second lactation. The content of protein mass fraction significantly prevails in the second lactation: by 0.14% (P