Relationships between beta-lactoglobulin and beta-casein polymorphisms and production traits in Brown Swiss and Holstein

摘要

To study the effects of beta-lactoglobulin ( beta -Lg) and beta-casein ( beta -Cn) polymorphism on milk production traits, milk samples from Brown Swiss (n=80), Holstein-Friesian (n=45) and East Anatolian Red cows (n=44) were analysed for beta -Lg and beta -Cn AA, AB and BB types using horizontal starch-gel electrophoresis method. Differences of both beta -Lg and beta -Cn among breeds studied in terms of proportion of phenotype were significant on gene variants. While the effects of beta -Cn phenotypes on studied yield traits were insignificant, there was a main effect of beta -Lg genotype on fat concentration, actual milk yield, actual fat yield, 305-days fat yield and lactation period in Brown Swiss and Holstein cows, but not on 305-days milk yield. Production and percentage of fat ratio might be maximized by the use of beta -Lg AA genotype and milk production by the use of beta -Lg AB genotype with selective goal in herds..