Effect of Dietary Protein and Fat on Changes of Serum Cholesterol in Mature Birds

Abstract

Male chickens 12 to 18 months of age were kept for 21 days on diets which contained 7.5, 15 or 30% of protein and 0.1 or 15% of corn oil. Samples of blood were obtained from each bird by heart puncture at the beginning, on the 10th and on the 21st day of the experimental period and the serum cholesterol level of each sample was determined by the Schoenheimer-Sperry method. All data were subjected to a statistical analysis. The largest increase in serum cholesterol was noted in birds which had consumed the least amount of protein. No apparent relationship existed between serum cholesterol and differences in feed intake or differences in the percentage of calories supplied by dietary fat. The serum cholesterol levels of hypercholesteremic birds dropped rapidly during the three-week experimental period but it did not drop to normal values in this period of time unless the protein level was high.