Genetic parameters associated with cholesterol in egg yolk and blood serum of the chicken

Abstract

A closed population of White Leghorns was used in this study to evaluate the importance of additive and nonadditive genetic variance in the inheritance of egg yolk and blood serum cholesterol in chickens. A diallel mating system was utilized to achieve the objectives of this investigation. The diallel mating system involved a double shift of males designed so that sets 1 through 5 were matings of low and medium egg yolk cholesterol classified dams with low classified males; and sets 6 through 10 were matings of high and medium egg yolk cholesterol classified dams with high classified males. In shift two the high cholesterol classified males were switched to sets 1 through 5, and the low males to sets 6 through 10. The statistical analyses were performed on the data according to the model outlined by Lerner (1950). Cholesterol determinations were established following the procedure described by Abell et al. (1952). This procedure was modified some by using color reagent of Zlatkis et al. (1953). Nonadditive gene effects are important in the inheritance of egg yolk and blood serum cholesterol in this population of Leghorn based on significant sire by dam interaction effects observed in these two characters. A total of 12.47% variance in egg yolk cholesterol and 16.01% of the phenotypic variance for blood serum cholesterol originated from the sire by dam interaction variance. Most of this variance results from dominance gene effects.