Effect of β-lactoglobulin and κ-casein genes polymorphism on milk composition in indigenous Zel sheep
The effect of β-lactoglobulin ( β-LG) and κ-casein ( CSN3) genotypes on milk composition were evaluated in Iranian indigenous Zel sheep breed. Genotypes were determined by PCR amplification followed by digestion with RsaI enzyme for exon II of the β-LG gene and SSCP method for exon IV of the CSN3 gene. Polymorphism was detected in all PCR products. β-lactoglobulin showed two alleles and three genotypes and CSN3 gene revealed two conformational patterns, respectively. Results indicated that there were significant associations between AB genotype of β-LG gene with higher fat and lactose percentages and also between K 1 pattern of CSN3 gene with higher lactose percentage. Therefore, it is feasible to improve milk composition in Zel sheep breed using β-LG and CSN3 genes.