title: Persistent rhythms of pineal and serum melatonin in cockerels in continuous darkness.
mesh_terms: D000818:Animals; D002645:Chickens; D002940:Circadian Rhythm; D003624:Darkness; D008029:Lighting; D008297:Male; D008550:Melatonin / Q000032:analysis* / Q000097:blood; D009043:Motor Activity; D010870:Pineal Gland / Q000032:analysis*
chemical_list: D008550:Melatonin