Fat, Fat Constants, and Phospholipid Content of Sow's Milk

The fat and phospholipid content of sow's colostrum and normal milk has been studied. A qualitative study of the fat of colostrum and milk of sows was also made. The effects of pasture versus dry-lot feeding during the gestation period were observed on the above criteria at different stages of lactation. The data warrant the following conclusions: The mean values for fat of the sows fed in dry lot during the gestation period were higher than those of sows fed in pasture during gestation. Total fat and phospholipid content decreased with stage of lactation but the phospholipid content, when expressed as percent of the fat, did not vary significantly. The iodine number of colostrum fat was significantly higher than that of 15- and 30-day milk fat. The saponification number and Hehner number of sow's milk fat were relatively constant and were not significantly affected by feeding or stage of lactation. The composition of sow's milk fat, as indicated by fat constants, closely resembles that of swine depot fats or lard.