Effects of the milk protein α-lactalbumin levels and folding on milk production in dairy cows.
2Faculty of agriculture, the Hebrew University of Jerusalem, Israel
Milk is secreted from epithelial cells in the Mammary glands. During the lactation period, the volume of milk rises and then drops. The drop in milk volume is corelated with a high rate of apoptosis of the epithelial cells. It is possible that one or more of the milk components is responsible for the apoptosis. α-lactalbumin (α-LA) is a main protein in milk, it is a regulatory part of the Lactose Synthase complex and the elevation in its concentration brings to elevated milk production. The morphology of α-LA can be altered by heat and acidity, one of the folding variants can form a complex that was shown to induce apoptosis in tumor cells.
In this study, we want to examine the relation between α-LA’s different morphs concentrations and milk production (i.e. volume and quality). We hypothesize that α-LA’s apoptotic form induces Mammary epithelial cell death, which in turn, brings to the drop in milk production.
Our preliminary results show that there is a significant difference in α-LA concentration, in milk that was obtained from cows at the beginning and at the end of the lactating period. Our future plans are to examine the levels of the two types of α-LA during the lactating period and to examine the effect of the apoptotic form on Mammary epithelial cells.