Effect of Whole-Milk and Replacement-Milk Feeding on the Fatty Acid Composition of Lymph Lipids in Young Calves

Abstract

Lipids in thoracic duct and intestinal lymph from young calves fed whole milk or replacement milk were analysed. Lymph triglyceride contained Cs and longer fatty acids with an average molecular weight of 260. The major components were 14 : 0, 16 : 0, 18 : 0, and 18 : 1, with small amounts of branched· chain and odd carbonnumber fatty acids. ClO fatty acid from milk lipid was apparently absorbed entirely into lymph. The composition of lymph triglyceride closely reflected that of the diet and showed no diurnal variation when the calves were fed once daily. Triglyceride from blood plasma resembled that from lymph except for higher proportions of 18 : 2 and 18 : 3.Feeding of replacement milk depressed lymph flow to 72% of that during whole·milk feeding and this was apparently due to a decrease in blood flow through the intestinal capillaries. There was also a reduction in the recovery of dietary longchain fatty acid as neutral lipid in lymph during replacement-milk feeding (50% compared with 83%) which could not be accounted for by malabsorption of saturated fatty acids in the replacement milk. These effects were attributed to the presence of a factor in the replacement milk which may have arisen from the oxidation of unsaturated fatty acids.