Figure 2.
Serum T and E2 concentrations in drakes and hens, respectively. (A) Serum T concentrations in drakes are at minimal concentrations from hatch through 10 weeks of age. T concentrations were significantly greater by 14 weeks of age, and again significantly increased 19 weeks and maintained into adulthood. Letters indicate statistically significant groups, a = p < 0.05, b = p < 0.01. (B) Serum E2 concentrations were also at baseline from hatch through week 10 and were significantly increased to adult-like concentrations by week 19. a = p < 0.001. Data suggest that gonadal development is occurring by week 14 and may be more advanced in hens compared to drakes.