Histological structure of the thyroid gland in the neonatal pig

The histological structure of the thyroid glands from 115 piglets that were stillborn or slaughtered at 0, 6, 12, 24, 48 or 72 h of age were examined. Thyroid follicle diameter decreased (p < 0.05) after birth and then increased (p < 0.05) through 72 h. Thyroid glands from stillborn piglets contained follicles whose diameters were similar to those oberved in 72-hour piglets. Thyroid follicles at all stages of development contained colloid and were surrounded by mainly cuboidal-columnar epithelium.