White leghorn chicken sex ratio manipulated with hormones

Treatment of white leghorn hens with a high dose of the hormone corticosterone five hours prior to ovulation resulted in the production of 83% male offspring, according to recent research. The research was conducted to determine the possibilities of manipulating layer hens into producing more female chicks than males.
The result was the opposite of that expected, because work in other avian species has shown that long-term treatment stimulates a female-bias. There was no adverse effect on the fertility of eggs compared to either control-treated hens or uninjected hens. In addition, an injection of testosterone exerted similar effects, producing a male-biased sex ratio (73%) and very little impact on fertility or the laying cycle. The use of progesterone interrupted the laying cycle in 77% of the hens injected. 
The study established optimal treatment and timing for producing a significantly biased, offspring, sex ratio in white leghorns. While the skew was not towards females, the researchers determined that the effects of a corticosterone inhibitor may be explored in attempt to produce a female-biased sex ratio.