αs1-Casein gene polymorphism in Katjang, Jamnapari, Boer and Boer-feral goats in Malaysia

Casein and milk serum or whey proteins are the two major proteins (about 95%) in mammalian milk. The casein protein comprises as1, as2, b, and k-casein while b-lactoglobulin and a-lactalbumin make up the whey protein. A study was carried out to characterise and determine the as1-casein protein gene polymorphism and genetic relationship in goat breeds available in Malaysia. A total of 115 heads of goats including Katjang, Boer, Boer Feral and Jamnapari were used in the study. Genomic DNA was extracted from the blood samples and amplified by PCR. Genetic variability was calculated using Popgene Software computer program. This study showed that casein gene exists in goat breeds found in Malaysia. All local goat breeds showed high frequency of as1-casein A, B and C alleles, which are related to high casein content in milk. The highest frequency of as1-casein A alleles was found in Katjang goats with a value of 0.61. The dendogram constructed based on genetic distance matrix using neighbour-joining method showed the genetic relation between the four breeds of goats. Boer and Boer-Feral goats were grouped together in one cluster whereas Katjang and Jamnapari populations were grouped in another cluster. The Boer goats differed genetically from the local Katjang or Jamnapari goats in as1-casein gene