On the basis of polymorphism in beta-lactoglobulin gene, a genetic structure of 155 cows bred in the Kujavian- Pomeranian voivodeship was detemined. Genotypes marking was conducted using the PCR-RFLP method. The results of the analysis, as regards polymorphism in beta-lactoglobulin gene, indicate that in the population under analysis BLG AB heterozygotes (50.32%) are twice as frequent as BLG AA (22.58%) and BLG BB (27.10%) homozygotes. Within beta-lactoglobulin small majority of frequency of gene B over A was shown, which is highly desired in dairy industry. The highest milk yield and its basic components was noted in maximum lactation for cows with BLG AA genotype, whereas milk of BLG BB cows exceeded milk obtained from cows with BLG AA and BLG BB genotypes
as regards fat and protein content.
