Histological Study of follicles in Thyroid Gland of Pati Ducks (Anas platyrhynchos domesticus) of Assam at Different Age Groups

The study was conducted on 42 number of Assam Pati ducks divided into 7 groups to study the histomorphological characteristics of thyroid glands from day-old to 40 weeks of age. The thyroid glands were collected from 6 birds in each group. The material was fixed and processed for histological studies. The microscopic structure of thyroid glands of Pati ducks revealed primarily the capsule enclosing the follicles that contained colloid. The capsule was made up of collagen and reticular fibers with scanty elastic fibers. The interfollicular space was narrow and consisted of fine collagen and reticular fibers that extended from the capsule. The interfollicular space was relatively devoid of elastic fibers Parenchyma of thyroid gland was composed of follicles. Follicles were lined by single layer of epithelial cells. As the age advanced, the size of the follicles increased with a mean diameter.