Abstract
Castration of photorefractory wild mallard drakes caused a significant increase in their plasma LH concentrations. Blood samples were then taken at monthly intervals for 16 months from 10 castrated drakes living outdoors in Kiel (54°N). Mean plasma LH levels remained elevated throughout the year. It is suggested that the testicular feedback is important for the maintenance of low LH levels during the refractory period, for the typical seasonal fluctuations of the plasma LH concentrations of intact birds, and probably for the induction of photorefractoriness.
Full Text 
Sign-in/Register to access full text options
Sign-in/Register to access full text options 
Published version (
Free)
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
