The world is going through the debate on hazardous effects of consumption of A1 milk on human health by producing of hazardous chemical compound like beta casomorphin-7 and how this is not the case with A2. The aim of the present study was to genotype the existing population of crossbred Holstein-Friesian (HF) cattle for polymorphism in â-Casein gene (CSN2) using PCR-RFLP technique. Total of 47 pluriparous cows of HF crossbred cattle were tested from Satara District (Maharashtra state). Genomic DNA was isolated from the blood samples. Isolated DNA samples were tested using PCR-RFLP technique. Restriction enzyme Dde I was used for detection of polymorphism. In the present study it was observed that the gene frequencies of A1 gene and A2 gene are 0.6383 and 0.3617, respectively. The genotype frequency of A1A1 genotype was 0.28 and that of A1A2 genotype was 0.72. In the present study, no correlation was observed between milk traits and CSN2 genotypes of crossbred cows.

Keyword: ? -Casein; Beta casomorphin-7; Genotype; Crossbred Cattle; Polymorphism; PCR-RFLP; Satara;