Table 3. 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.

Challenge Species	A. Broilers from unvaccinated hens raised coccidia free (ie, in wire cages)		B. Broilers from unvaccinated hens raised with exposure to coccidia (ie, in floor litter)		C. Broilers from purified gametocyte antigen vaccinated hens, raised with exposure to coccidia (ie, on floor litter)
	Average Weight±S.D. (g)	% Weight loss vs. unchallenged, unexposed broilers	Average Weight (g)	% Weight loss vs. unchallenged, unexposed broilers	Average Weight±S.D. (g)	% Weight loss vs. unchallenged, unexposed broilers
Unchallenged	2346±157	-	1791±367	23.6	2355±279	-
E. tenella	2176±210	7.2*	1869±214	20.3	2343±172	0.5
E. acervulina	2046±206	12.8*	1861±174	20.7	2231±245	5.3
E. maxima	1910±250	18.6*	1833±316	21.9	2151±175	8.6
E. mitis	1992±188	15.1*	1795±312	23.5	2189±313	7.0

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<0.05; one-way ANOVA, Student's t-test). There was no significant weight loss in challenged birds in Group B or Group C versus unchallenged birds.