Endocrine Abstracts

Much less information is available on the thyroid hormones at different age groups, laying, non-laying and methimazole (MMI) treated japanese quails. All birds were kept under 14:10 hour light schedule and were provided feed and water adlibitum. Fifteen japanese quailsin each age groups, laying, non-laying and MMI treated were decapitated for collection of plasma. Thyroid hormones (T3 and T4) were estimated using ELISA commercial kits. The results showed that plasma thyroid hormones concentration decreased with increasing age. The laying quails had lower thyroid hormones levels than the non-laying birds of the same age group, thus decreased T3:T4 ratio. A lower T3 and higher T4 concentration was found in the MMI treated birds as compared to normal of the same age group. Mean thyroid weight, the degree of thyroid hyperplasia and height of the secretory epithelial cells were significantly greater in MMI treated birds as compare to normal. Histological examination of thyroid revealed a loss of colloid and increased cellular invasion of follicles in thyroid of MMI treated birds.