Identification of the frequency of CSN1S2 gene alleles and the effects of these alleles and parity on milk yield and composition in Saanen goats
The expression of CSN1S2 gene is known to regulate the α-S2 casein levels in milk composition, moreover is estimated to affect the milk yield and composition in goat. However, the knowledge about the CSN1S2 gene on milk yield and composition is restricted in Saanen goats. Therefore, this study aimed to specify the effect of CSN1S2 polymorphisms on milk yield/composition parameters. Genotyping of Saanen goats (n=120) was performed by PCR-RFLP methods. The GLM procedure was prefered as statistical analysis to defined the effect of those variations on investigated traits. The result showed that the AA (26.67%), BB (33.33%) and AB (40.00%) for A-B variant; N* (94.17%), N*0 (5.83%) for D-0 variant; FF (7.50%), NF/NF (65.83%) and F/NF (26.67%) for F variant in Saanen goats. The effect of A-B allele of CSN1S2 gene (P<0.05) and parity (P<0.001) on milk composition yields were found significant in the current study. However, the effect of A-B allele on lactation milk yield was determined tended to be significant (P=0.090). Moreover, significant correlations between the milk composition parameters such as fat, protein, TS (total solid), SNF(solid not fat), casein, or lactose were observed (P<0.001). The novel outputs might be useful for developing goat breeding strategies or improving the dairy industry, especially for milk products.