EN
The aim of the present study was to verify the hypothesis that α-lactalbumin (LALBA) gene polymorphism may be a factor differentiating defence mechanisms in cattle. The association between LALBA polymorphism and the levels of blood indices characterising defence functions were examined in a group of 129 female calves and young heifers, produced by random mating of parental couples. The levels of blood diagnostic indices were determined four times: at 15 to 30 d, 3 months, 6 months, and 12 months of age. The genotypes distribution within the progeny was uneven (LALBA AA - 59.7%, LALBA AB - 35.7%, LALBA BB - 4.6%). At all times of the analysing, statistically significant differences between LALBA genotype groups were observed in the number of leukocytes (LALBA AA>LALBA BB), and the percentage of eosinophils (LALBA BB> LALBA AA). LALBA polymorphism also differentiated the percentages of lymphocytes (15 to 30 d, 3 months), neutrophils (15 to 30 d, 3 months, 12 months), basophils (6 and 12 months), and monocytes (6 months). Differences in the levels of total protein and γ-globulin were relatively low in animals aged 15 to 30 d, 3 months, and 6 months, but high in those aged 12 months (LALBA AB>LALBA AA>LALBA BB). There was a correlation between LALBA polymorphism and lysozyme activity (LALBA AA>LALBA AB> LALBA BB). Higher values of the NBT reduction tests were recorded in calves aged 15 to 30 d, as compared with older ones.