Effect of Nutritional Variance of Energy and Crude Protein on Sex Ratio and Development of W-36 Parent Offspring

Past studies have shown a link between maternal condition or resource availability, and the resultant sex ratio of offspring in avian species, both wild and domesticated. This study utilized 200 male and 400 female chicks from a W-36 white leghorn parent stock and assessed the effects of three diets with different caloric and protein concentrations on the sex ratios of the Hy-Line W-36 laying hens. As expected, the development of both parent and filial generations was significantly affected by diet or egg composition, respectively. Sex ratio was not significantly different from an assumed population proportion of 0.50 across all experimental groups, but did approach significance among offspring of parents switched from “High” to “Control” diets at 17 weeks of age. Results suggest that continual availability of either high- or low-nutrient density feed resources does not predispose hens to bias the sex ratio of their offspring; however, a sudden change in diet, particularly to one of lower protein concentration, may influence such an effect. Further trials are needed to assess the efficacy of diet alteration prior to reproductive maturity as a means of sex allocation manipulation.