The effect of maternal immunization with purified gametocyte antigens of Eimeria maxima and natural immunity induced by exposure to oocysts on weight loss caused by various species of Eimeria in offspring chickens.

Commercial broiler breeder hens were vaccinated and their offspring raised as described in the legend to Figure 2. At 34 days of age, the birds were divided into fourteen cages each containing five birds. The chickens were challenged by infecting individual birds with oocysts of one of the following species of Eimeria: E. maxima (25,000 oocysts), E. tenella (25,000 oocysts), E. acervulina (80,000 oocysts) or E. mitis (120,000 oocysts) with three replicates of five chickens per species. Two replicates of five chickens were left unchallenged (sham dosed with sterile water). The birds were weighed 2 weeks after infection. In Group A, challenge infection with every species of Eimeria caused a significant loss of weight versus unchallenged chickens (* p