The Relationship Between Diet and Dwarfism in Diverse Genetic Backgrounds on Egg Parameters

The phenotypic expression of dwarfism on egg formation was investigated by examining the weights of eggs and specific egg components from diverse weight lines into which the sex-linked dwarf gene, dw, had been introduced. The dw gene depressed egg weights, with a realtively greater reduction occurring in the low-weight than in the high-weight line. When expressed as a percentage of egg weight, egg shell was reduced by dw in both lines. Percentage yolk and albumen were not significantly affected by dw. Absolute weights of all components paralleled body weights, with the exception of shell membranes which tended to be relatively constant. Feeding diets containing higher nutrient densities partially alleviated the depressive effect of dw on egg weights. High density diets also attenuated the depressive effect of dw on percentage egg shell in the low-weight but not the high-weight line. Diet did not significantly alter the percentage of either yolk or albumen. It was postulated that some of the detrimental effects of dw on egg formation were related to insufficient food consumption due to defects in the basic mechanisms regulating appetite and feeding behavior.