The distribution and types of alpha-s(1)-casein, beta-lactoglobulin, beta-casein and kappa-casein in Holstein cattle were identified.
It was determined that the frequencies of alpha-s(1)-casein were 0.958 and 0.042 for alpha-s(1)-Ka(B) and alpha-s(1)-Ka(C); beta-lactoglobulin, 0.516 and 0.484 for beta-lgn(A) and beta-lgn(B); beta-casein, 0.995 and 0.005 for beta-Ka(A) and beta-Ka(B): and kappa-casein, 0.677 and 0.323 for kappa-Ka(A) and kappa-Ka(B), respectively.
The differences between the empirical and theoretical distributions of the alpha-s(1)-casein, beta-lactoglobulin, beta-casein and kappa-casein genotypes were not significant.
The effects of the alpha-s(1)-casein, beta-casein and kappa-casein types on milk yield traits were not significant, while the effects of the beta-lactoglobulin types were significant (p<0.05). beta-Lgn(AB) type cows produced the highest 2x-ME-305 daily milk yields. The effects of alpha-s(1)-casein types on the length of the lactation period were not significant, while the effects of the beta-lactoglobulin. beta-casein and kappa-casein types were significant (P<0.05).
The distribution and types of alpha-s(1)-casein, beta-lactoglobulin, beta-casein and kappa-casein in Holstein cattle were identified.
