INFLUENCE OF CSN3 MARKER ON MILK COMPOSITION IN ROMANIAN BROWN AND ROMANIAN SIMMENTAL CATTLE FROM S.C.D.C.B. ARAD

Milk yield and composition in cattle are typical quantitative traitswhich areinfluenced by environmental factors and allelic variations. K-casein is a proteinexpressed in milk and, due to is polymorphism, may serve as a molecular marker foryield, composition and technological properties of milk. The objective of this studywas to compare the relation between the genetic marker CSN3 (k-casein) and theobserved milk traits in selected cattle groups. In our study we analyzed the milktraits of 32 Romanian Brown dairy cows and 54 Romanian Simmental dairy cows.The experiments described in this paper show clear evidence that -CSN3 genotype isinvolved in milk protein enrichment. The CSN3 gene of BB genotype showed a grateinfluence on protein yield. The relation between CSN3 genotype and milk proteinwas found to be significant in both cattle breed.