Abstract

The influence of season on the composition of milk from approximately 200 Beta-lactoglobulin (B-LG) AA and 200 B-lactoglobulin BB phenotype cows was determined for the 1992/93 and 1993/94 seasons. Marked seasonal fluctuations were observed in all components measured: protein, casein, whey protein, ash, lactose, alpha-lactalbumin, B-LG, alpha/s- casein, Beta-casein, k-casein (k-CN), bovine serum albumin, calcium, magnesium, sodium, potassium, chloride, and phosphate. Significant differences in composition were observed between the AA and BB phenotype milks, with the Beta-LG BB phenotype milk containing more total protein, casein, fat, and total solids, whereas the Beta-LG AA phenotype milk contained more whey protein, Beta-LG, and had a higher ratio of Beta- LG to k-CN. Such differences in composition could have a marked effect on the physicochemical characteristics of these milks. The higher concentration of casein found in the Betal-lactogloblin BB type milk should make this milk type more suitable for the manufacture of cheese and casein.

TC, Reid, and KJ Botica

Proceedings of the New Zealand Society of Animal Production, Volume 55, , 50-53, 1995