The influence of genetic β-lactoglobulin polymorphism on the quantity and quality of milk of the Simmental breed in Serbia

The study of the link between genes controlling protein polymorphism and milk performance traits of domestic animals has great economic importance from a selection point of view, as it reduces the generation interval, leading to increased productivity in livestock. The objective of this paper was to establish the influence of genetic ? -lactoglobulin polymorphism on the quantity and quality of milk of the simmental breed in Serbi?. For the research blood samples were taken from a total of 157 Simmental cows. The genotypes of Simmental cows for ?-lactoblobulin and their effect on quantitative milk performance traits were determined using the PCR-RFLP analysis. The variability of traits influenced by the genetic polymorphism of ?-lactoblobulin was statistically very highly significant (p <0.0001) for milk yield in standard lactation and milk fat and protein yields, while it showed no statistically significant variability (p> 0.05) for content of milk fat and protein. The genotype cows achieved a 121 kg and 338 kg increase in milk production compared to the BB genotype and AA genotype cows, respectively.