Polymorphism of Kappa-Casein Gene (CSN3|Alw 44I) and Its Effect on Milk Yield and Compositions in Indigenous Senduro Goat

Casein is one of the major milk proteins approximately 80-83% of total protein. The CSN3 gene has been broadly studied due to its important influence on the milk properties. Senduro goat is local breeds in Indonesia that provide milk. This study was aimed to analyse CSN3 gene polymorphism and its association with milk production and composition on Senduro goat. A total of 42 lactating Senduro goat were used in study from parity 1 to 4. Blood and milk samples were collected in Senduro district, Lumajang. The traits observed were milk yield, fat, lactose, solid non-fat, total-solid, and protein. The CSN3|Alw 44I polymorphism was analysed using Polymerase Chain Reaction-Restricted Fragment Length Polymorphism method. The result showed that three genotypes (CC, CT, and TT) and two alleles (C and T) were found. The frequencies of CC, CT, and TT genotypes were 0.450, 0.500, and 0.050 respectively, while the frequencies of C and T allele were 0.702 and 0.298, respectively. The different genotypes didn’t significantly affect milk production and compositions. Descriptively, Senduro goat with TT genotype had the highest milk production and compositions. In conclusion, the polymorphism of CSN3|Alw 44I was polymorphic and could differentiate milk production and compositions among genotypes (TT>CT>CC).