Evaluation of Steviol Injection on Chicken Embryos: Effects on Post-hatch Development, Proportional Organ Weights, Plasma Thyroid Hormones and Metabolites

At day 1 of incubation, eggs were injected with high levels of steviol (1.5 and - mg per egg). At hatch, no effect of steviol injection was observed on plasma thyroid hormone levels, hatchability, body weight and chick quality. Proportional liver weight of chicks receiving the highest steviol dose was significantly higher, while the proportional bursa weight of the steviol injected groups was significantly lower compared to that of the control. Moreover, plasma lactate dehydrogenase activity of chicks from the highest steviol injected group was significantly higher compared to control values. At 1 days of age, proportional liver weight of chicks of the - mg steviol injected group was significantly lower compared to that of the control treatment. It is concluded that injection of a high dose of steviol has no effect on plasma thyroid hormones and has only slight and temporary metabolic effects on the chicken embryo.