Effects of Dietary Fat on Amounts of Cholesterol Transported by Mesenteric Lymph in Calves Fed Milk

Abstract

Five nonruminating male calves were prepared surgically with shunts from mesenteric lymph duct to posterior vena cava and sequentially were fed diets of reconstituted skim milk and skim milk plus supplemental cholesterol plus soybean oil, beef tallow or milk fat. Calves received skim milk for 2 days, followed by the other diets for 4 days each in a predetermined order. On the 2nd and 4th day each diet was fed, lymph was collected hourly for 8 h, starting 1 h before the morning feeding. Cholesterol transported in lymph increased markedly in the hour after feeding and then declined rapidly but to quantities still greater than prefeeding. Average cholesterol in lymph was 1.7, 2.8, 3.7 and 4.2 mg/(h .times. kg body wt) for the skim milk, soybean oil, tallow and milk fat diets, respectively. No difference was significant between 2nd and 4th day totals for each diet. Because cholesterol rate of flow quickly responded to new diets and stabilized within 2 days, this technique permitted evaluation of effects of dissimilar dietary fats on the amounts of cholesterol and triglyceride transported by mesenteric lymph.