Effect of Fertilization and Age of Hen on the Cholesterol Content of Chicken Egg Yolk

Abstract

The cholesterol content of infertile and fertile eggs from White Leghorn hens was compared. In Trials 1 and 2, infertile eggs were collected, a male was introduced, and fertile eggs then collected from the same hens. In Trial 3, two pens of hens were trapnested. The first pen contained hens only, and the second pen contained hens plus a male. After the desired number of eggs were collected from each hen, the male was moved to the other pen. Twenty-one days were allowed to elapse and eggs were again collected.In Trial 1, there were no statistically significant differences between fertile and infertile eggs in wet yolk weight, dry yolk weight, mg. cholesterol per g. dry yolk, or total yolk cholesterol. In Trial 2, fertile eggs were significantly higher than the infertile eggs in dry yolk weight (P<0.05), mg. cholesterol per g. dry yolk (P<0.05), and total yolk cholesterol (P<0.01). In Trial 3, there were no statistically significant differences between fertile and infertile egg values for any of the egg traits examined. When results were analyzed for differences due to age of hen, wet yolk wt., dry yolk wt. and total cholesterol were significantly higher (P<0.05) for eggs laid by the 12.5 month old hens than for eggs laid by the same hens 11.0 months old. Cholesterol concentration did not change with the age of the bird. The results from this study show that fertile eggs are not lower in cholesterol content than infertile eggs.