Moleculer analysis of genotype kappa casein and composition of goat milk Etawah grade, Saanen and their crossbred

Abstract

Polymorphism of goat casein gene closely linked to the quality of milk protein. κ-casein is one of the casein fractions that influence the shape and stability of grain milk. This study is aimed to identify the variation of genotype κ-casein and related with milk quality from Etawah grade, Saanen and their crossbreed (PE-SA). The number of dairy goats used in this study was 150 animals consisted of Etawah grade (48 animals), Saanen (51 animals) and PE-SA (51 animals). Steps of experiment were: blood and milk sampling collection, DNA amplification by PCR and the product digestion using Pst1 enzyme, κ-casein gene sequencing and analyzing the quality of fresh milk. The results showed that κ-casein gene is monomorphic by PCR-RFLP (Pst1) for all the goat breeds, but DNA sequencing indicated 38 point of mutation.  Observation on goat milk quality showed that Etawah grade milk had highest (P < 0.05) density value (1.033 ± 0.002) and solid non fat (9.577 ± 0.704%) than those of Saanen and PE-SA fresh milk goat.

Key Words: Dairy Goats, Κ-Casein Gene, PCR-RFLP, Milk