The Role of the Bursa of Fabricius in Adrenal Response and Mortality Due to Eimeria tenella Infections in the Chicken

The adrenal ascorbic acid and adrenal corticosterone concentrations were found to be elevated in chicks infected with cecal coccidiosis. This change took place during the acute hemorrhagic phase of the infection. The response of bursectomized chicks was compared to that of intact chicks and was found to be similar with respect to changes in adrenal constituents and adrenal size. A markedly greater mortality due to infection was observed among the bursectomized birds and it was tentatively proposed that this was due to impairment of the host's immune response.