Effects of Dietary Fats for Laying Hens on the Fatty Acid Compositions and Cholesterol Contents of Liver, Abdominal Adipose Tissue, Plasma and Egg Yolk Lipids

Abstract

White Leghorn hens were fed diets containing of soybean oil, coconut oil, lard or beef tallow for a period of 50 days. The feeding of soybean oil to hens resulted in considerable increase of 18:2 and 18:3 acids accompanied by decrease of 16:0 and 18:1 acids in liver, abdominal fat, blood and egg yolk lipids. On the case of coconut oil feeding, the increase of 12:0 and 14:0 acids and the decrease of 18:1 and 18:2 acids were observed in the above-mentioned lipids. The fatty acid compositions of lipids obtained from hens of lard diet group were fairly resembled to that of lipids from beef tallow diet group. In general, the fatty acid patterns of respective lipids from hens reflected the fatty acid compositions of diets, and it was considered that the abdominal fat was affected most markedly by dietary fats. Although the total cholesterol contents in egg yolk were not significantly differed among each diet groups, the total cholesterol contents in liver, adipose tissue and plasma of coconut oil diet group and of beef tallow diet group were higher than those of soybean oil and lard diet groups. Triglyceride, phospholipid and cholesterol contents in plasma were differed among the diet groups, and the values of every lipid components in serum were as follows in increasing order: soybean oil, lard, beef tallow and then coconut oil diet groups. The each other's proportions of plasma lipid components were nearly the same values on all diet groups, that is the proportional values of TG:PL:TC were about 15:10:3 in weight percent, and it seemed that those lipid contents in plasma were parallels to the saturated fatty acid contents of plasma neutral lipid fractions.