Genetic Basis of Yolk Cholesterol Content

The genetic basis of yolk cholesterol level was studied in two randombred populations (AC and ARB) of domestic fowl. The association of yolk cholesterol levels with blood cholesterol levels, fertility, hatchability, mortality, egg production and specific gravity were also examined. The yolk cholesterol content in the AC population was 22.8 ± 2.8 mgs. cholesterol per gram of yolk compared to 19.2 ± 1.2 mgs. in the ARB population. There was a significant sire effect on yolk cholesterol level in both populations, but the variability was greater in the AC population. The mean heritability estimate for yolk cholesterol in the AC population was .3, while for the ARB population it was .2. There was no statistically significant phenotypic correlation between yolk cholesterol level and hatchability, fertility, specific gravity or mortality. A significant correlation between yolk cholesterol level and egg production was observed, but this correlation was of low magnitude.