Growth and food intake of intact and pinealectomised chickens treated with melatonin and triiodothyronine.
Male chickens of an egg-laying strain were used in an investigation of the effects of pinealectomy at 1 d after hatching. Pinealectomised birds killed at 28 d of age were significantly heavier than sham-operated chickens; intraperitoneal treatment of intact birds during the same period with 10 mg melatonin/kg d depressed weight gain, while 200 micrograms triiodothyronine (T3)/kg d given intramuscularly had no effect. Pinealectomized birds aged 11 weeks ate some food during the night, in contrast to intact birds, and ate significantly more food per 24 h; their short-term food intake responded to melatonin and T3 in a manner similar to that of intact birds. The electroencephalogram (EEG) of pinealectomised birds was affected to a slight degree of darkness, while in intact chickens there is a rapid and marked change in the EEG.
D000818:Animals; D001835:Body Weight / Q000187:drug effects*; D002645:Chickens / Q000502:physiology*; D003624:Darkness; D004435:Eating / Q000187:drug effects*; D004569:Electroencephalography / Q000662:veterinary; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D010870:Pineal Gland / Q000502:physiology*; D014284:Triiodothyronine / Q000494:pharmacology*
D014284:Triiodothyronine; D008550:Melatonin