EFFECT OF KAPPA-CASEIN AND BETA-LACTOGLOBULIN GENE POLYMORPHISM ON THE MILK SUITABILITY FOR CHEESE-MAKING FROM HOLSTEIN COWS OF DIFFERENT LINES

Abstract

A comparative study of the genotypes of cows, which belong to the leading
lines of the Holstein breed (Vis Back Ideal 1013415 and Reflection Sovereign 198998), was
carried out. The research provided for the study of the practical significance of using the molecular genetic resources of experimental animals, which affect the increase in the volume of
produced milk with optimal fat and protein ratios, which have a positive effect on its technological properties, determining its suitability for cheese-making. The study of these characteristics using modern molecular genetic methods and the introduction of research into milk production will allow the intensification of dairy cattle breeding. The existing genes, which are
responsible for the level of milk productivity and milk suitability for cheese-making were
analyzed in the research. CSN3 – kappa-casein, is responsible for the parameters of milk protein content and BLG – beta-lactoglobulin, is responsible for the characteristics of the casein
curd, which affect the yield of cheese, as well as its qualitative characteristics, which are very
important in cheese-making. Studies have shown that more milk was received from cows of
the Vis Back Ideal 1013415 line. Their average milk yield was 12849,4 kg of milk. 11222,1
kg were produced from herdmates of the Reflection Sovereign 198998 line. Among the studied groups of experimental cows, there were an uneven number of animals, which had desirable combinations of genotypes, whose qualitative composition of milk mostly meets the requirements of cheese-making. In the 1st group, we found a larger number of animals (11,8%,
or 12 head), which had the desired ratios of markers responsible for the fat and protein content in milk. Among the herdmates of the 2nd group, there were 7 head of such animals, which
is 10,3%. Identification of desirable economic traits will allow the formation of gene pools of
herds and breeds with the necessary gene combinations.