Evaluation of effects of bursa Fabricius extracts on development of immunocompetence in neonatally bursectomized cockerels.

Abstract

SummaryThis experiment was designed to serve as a careful test of the hypothesis that the bursa of Fabricius produces a hormone responsible for the development of immunocompetence. Cell- and bacterium-free extracts of the bursa or pancreas were administered subcutaneously for 23 days to neonatally bursectomized cockerels. Immune responses were tested at 30 and 77 days of age. The bursal extracts produced no significant repair of the immuno-deficient state. The responses to BSA and B. abortus antigens did not differ in bursectomized birds receiving bursal or pancreas extract. However, all bursectomized birds showed significantly lower primary and secondary responses than did sham operated birds. No significant differences were measured in the number of splenic bursal dependent centers between bursectomized birds receiving bursal extract and their controls. On the basis of our findings, we conclude that prior evidence for a humoral function of the bursa should be challenged.