Some aspects of the chemical composition of the milk fat globule membrane during lactation

Abstract

Summary The protein, phospholipid and neutral lipid composition of a deoxycholatesoluble fraction (DOCM) from bovine milk fat globule membrane (FGM) was determined, at intervals during lactation, in 3 cows maintained at a constant level of food intake. It was suggested that the appearance of free fat in washed cream during the first 2 days post partum was related to membrane stability in colostral secretion. Differences between the cows in DOCM yield (mg/100 g cream lipid) and composition were greatest during the first 25 days post partum. DOCM yield increased markedly as lactation proceeded in one animal, and this was thought to be due to a decrease in globule size. Variation in DOCM composition was principally due to an alteration in neutral lipid content. There were few differences, however, between the quantities of phospholipid and protein in DOCM for all 3 animals, and similarly the percentage composition of the major DOCM phospholipids varied little, phosphatidyl choline being the predominant phospholipid.