Effect of dietary oil, cholesterol, and soysterols on the lipid concentration and fatty acid composition of egg yolk, liver and serum of laying hens.

Effect of dietary lipid factors (saturated and unsaturated oil, zoo and phytosterols) on the lipid concentration and fatty acid composition of egg yolk, liver and serum of the laying hen were studied. Single Comb White Leghorn laying hens, at 30 weeks of age, were fed two basal diets containing 8.0% hydrogenated coconut oil (HCO) or safflower oil (SFO), with or without supplemental cholesterol (1.0%), soysterols (2.0%) or combination of both. When HCO basal diet was fed, both liver weight and lipid content were significantly (P less than .01) increased as compared to hens fed the SFO diet. Cholesterol feeding increased total lipid content in liver and serum, whereas soysterol feeding reduce or diminish lipid accumulation caused by the cholesterol treatment. Both dietary cholesterol and soysterols alter the fatty acid composition of liver, serum and egg yolk lipids by increasing oleic acid and decreasing palmitic and/or stearic acids. These changes were significantly greater upon feeding cholesterol than soysterols. However, the simultaneous feeding of cholesterol with soysterols exerted the least effect on the fatty acid composition.