Effect of β-lactoglobulin and κ-casein genes polymorphism on milk composition in indigenous Zel sheep
Abstract. 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 K1 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.