Effect of 17β-trenbolone on male and female reproduction in Japanese quail (Coturnix japonica)

The anabolic steroid 17β trenbolone (17β-TB), a known endocrine disrupting chemical, may influence reproductive functions in avian wildlife. We evaluated the effects of dietary exposure to 17β-TB at 5 and 20 ppm on reproductive functional endpoints in Japanese quail during and after sexual maturation. In the male, 5 and 20 ppm treatments revealed no differences in body and testes weight, testes histology, plasma testosterone concentrations, or size and weight of the foam glands. However, the onset of foam production was significantly earlier (days of age) in the 20 ppm males. In females, dietary 17β-TB at 20 ppm caused a reduction in the number of maturing yellow yolk follicles and overall egg production. Plasma testosterone concentrations were reduced compared to controls. Histology of the oviductal sperm storage tubules was normal in all treatments. The number of sperm holes, sites on the perivitelline layer (PVL) where sperm bound and hydrolyzed a path through the PVL, was significantly greater in the 10th egg laid compared to the 1st egg laid in the 20 ppm treatment. Potential effects, albeit transient, on endpoints associated with male maturation warrant further investigation into the sensitivity of these measures in the event of embryonic and/or trans-generational exposure to 17β-TB.