Thyroid-ovary relationship in laying hens

This investigation included the study of thyroid honnones acti vi ty during the ovulatory cycle of H U 1 and Doki - 4 hens. The role played by the pituitary in regulatine thyroid activity of these hens was also studied.In the first experiment 40 HNL hens were used. Dlood was collected from hens With regular laying patt.ern, after slaughterir~ at ovulation( egg laying ), 5, 10, 15 atld 20 hr after ovulation.Serum was collected from each hen and equal volumes from individuals of identical experimental groups were pooled toeether. The pituitaries andthyroids of the hens Were dissected and weighed.Tho T S H contents of the pituitaries and serum were determined biologically using the thyroid weight rQsponse of one-day old male chicks. The thyroid hormones activity of the sera of hens were determined by biological and radioimmunoassay methods. Histol