Effect of feed composition on cholesterol content of the table egg

The objective of the experiments presented in this paper was to determine t he influence exerted on the cholesterol content of the table egg by the com position of feed, more specifically by its cholesterol and fibre content as well as by some feed components including oats, maize germ meal, green alf alfa, sunflower oil and pork-fat. The experimental feeds were adjusted to d ifferent cholesterol concentrations by adding different amounts of crystall ine cholesterol (0, 0.5, 1.0, 1.5, and 2.0%, respectively). After feeding t he mixed feeds supplemented with different levels of cholesterol, no defini te correlation was demonstrated between dietary cholesterol level and the c holesterol content of the blood plasma and egg yolk. The feeding of lard an d sunflower oil (each at 5%) caused a significant (P<0.001) increase in egg yolk cholesterol concentration (ChCc), with the increase caused by sunflow er oil being greater. The addition of 10% oats to the laying mash lowered e gg yolk ChCc (P<0.05) and raised the ratio of unsaturated fatty acids (C16: 1 and C18:2) while decreased that of stearic acid (C18:0) in the egg yolk. A slight elevation of the fibre content of layer diets (0.9% and 2.0%, resp ectively) slightly reduced egg yolk ChCc. Egg yolk ChCc considerably (P<0.0 01) decreased after the feeding of maize germ meal at an inclusion level of 10%. The feeding of maize germ meal increased (P<0.05) the concentration o f oleic acid in egg yolk (C18:1) and decreased (P<0.01) that of palmitic ac id (C16:0). The feeding of alfalfa did not cause significant changes (P>0.0 5) either in ChCc or in total cholesterol content (ChCt) of the egg yolk in these experiments.