Effect of temperature as a stresser on white blood cells, adrenals and bursae of Fabricius of chicks

¹ Mississippi State University, State College, Mississippi

The effects of extreme environmental temperatures on white blood cell counts and weights of the bursa of Fabricius—a lymphoepithelial gland—and adrenal glands of young birds was studied. Birds bled immediately after 15–30-minute exposures to temperatures between 112° and 118°F revealed a marked decrease in total white blood cells and percentage of heterophils and an increase in percentage of lymphocytes. When the birds were bled 2 hours after 30 minutes of heat exposure, there was a marked increase in percentage of heterophils and decrease in percentage of lymphocytes. Exposures of 30 minutes to 41°– 44°F temperatures did not have a consistent effect on white blood cells. Neither temperature affected the weights of the bursa of Fabricius or adrenal glands.