The induction of ovulation in starving pullets using mammalian and avian gonadotropins.

Laying pullets deprived of all nourishment, except water and oyster shell grit, showed ovarian degeneration and cessation of ovulation within 72 hours. Injections of gonadotropins prevented ovarian degeneration and, in some cases, induced regular daily ovulations for 8 or more days after removal of food. With the limited range of doses investigated, intramuscular injections of dried chicken anterior pituitary glands were more effective in causing daily ovulations than was a combination of intramuscular injections of mammalian follicle stimulating hormone with intravenous injections of mammalian luteinizing hormone. There was a progressive decline in the weight of yolks ovulated by starved, hormone-supported pullets. It is suggested that failure to lay in the starved pullet is primarily due to failure of the pituitary to secrete adequate gonadotropins. The possibility that less extreme dietary deficiencies affect egg production via pituitary function is discussed briefly.