Seasonal, Strain and Hatch Effects on Egg Quality Traits

THE identification of specific genetic or environmental factors affecting the variation of egg quality traits should be of value in designing more accurate techniques for their evaluation in breeding operations. Strain differences in albumen quality are more easily detected than are those in shell quality, according to King and Hall (1955). The existence of negative genetic correlations between two traits under selection would reduce the expected gain due to selection within a strain; selection for only one of these traits would be expected to cause a decrease in the other, in proportion to the selection pressure and the magnitudes of the correlation between the traits and their heritabilities. A negative correlation between albumen quality and egg production was reported by Johnson and Merritt (1955) and confirmed by Goodman and Godfrey (1955). To date, there is limited knowledge of the specific environmental factors influencing blood and meat spot incidence. The effect . . .