Published online by Cambridge University Press: 06 April 2009
Chicks were treated with cyclophosphamide during the first 3 days of life in order to effect chemical bursectomy. They subsequently showed a reduced capacity for the production of serum agglutinins to Brucella abortus and immunolysins to sporozoites of Eimeria tenella. They also developed a reduced immunity to E. tenella or E. maxima compared with that produced in normal birds. The evidence provided by these experiments for the role of circulating antibodies in immunity to coccidiosis is discussed.