Characterization of bovine milk from indigenous species from Sri Lanka

Abstract: Sri Lanka is a country in south Asia that from the beginning of the 21st century, until 2016 almost doubled their quantity in milk import, this to meet their national market demand for dairy products. The country is divided into different agroecological zones, which are the up-country, mid-country, and the lowlands. The dry lowland zone is the largest zone of the country, and the environment is severe for cattle holding, especially for European breeds that are used to a more temperate climate. In this zone the indigenous cattle breeds are the most common as they are better adapted to the environment than imported breeds as e.g., Jersey and Friesian. However, the indigenous cattle are known to have a low milk production. In this study, the objective was to investigate and compare the protein profile and total proteolysis with gross composition, to find potential differences between cattle types. Four different cattle types were investigated: the Thamankaduwa White cattle, Lankan cattle (both indigenous cattle types) and crossbreeds of Jersey cattle and Friesian cattle. A total of 15 milk samples from each cattle type were analyzed by a fluorescence method for total proteolysis and by capillary electrophoresis for identification and quantification of the protein profiles. Each sample represented one individual, and a total of 15 individuals represented each cattle type. The milk samples were collected by a representant from the Rajarata University of Sri Lanka, where the gross composition of the samples was analyzed. Protein profile, total proteolysis and pH-value were measured and analyzed at the Swedish University of Agricultural Sciences, Uppsala. Total fat, solid non-fat, somatic cell count, pH-value, κ-casein, and total proteolysis differed significantly between the cattle types in this study. Although, for the solid nonfat and somatic cell count the significance was low (p<0.05) with a high standard deviation for all cattle types. Thamankaduwa white cattle was the cattle type that differed with the highest significance (p<0.001) for the parameters pH-value, κ-casein, and total proteolysis, compared to the other cattle types. However, the significant differences in this study are based on limited number of factors. Also, the low number of individual cows in each group can be considered as a limitation. Therefore, this study can be considered as a contributing part in the work of deeper investigations of the indigenous cattle types in Sri Lanka.