Effect of High Environmental Temperature on Internal Organs of Chickens

White Leghorn females were subjected to 18° C. constant temperature or 21–38° C. variable temperature for a period of 16 weeks. Changes in internal organs observed as a result of the elevated temperature included increased adrenal size and decreased thyroid and liver size. Focal necrosis of the cortical mass and, in some cases, slight granulation of the cortical tissue were observed in the adrenals. The epithelial lining of the thyroid follicles was lower. The pituitary gland showed slight hyperplasia and hypertrophy of the basophil cells. Hepatic changes were characterized by degeneration of parenchyma cells, fatty degeneration, congestion of hepatic vessels, nuclear degeneration of various types, leucocytic infiltration, and some focal necrosis.