Effects of different doses of Eimeria tenella inoculated on microstructure of small intestine in chickens
To study the effects of different doses of E.tenella inoculated by mouth on microstructure of small intestine in chickens,a total of 60 20-day-old chickens were selected and divided into control group and experiment group Ⅰ,Ⅱ,Ⅲ,Ⅳ and Ⅴ.The chickens in each experiment group were inoculated with 0.5×104,1.0×104,2.0×104,4.0×104 and 8.0×104 E.tenella oocysts by mouth,respectively,for 7 days,while the chickens in control group were inoculated with saline.At the end of the experiment,the chickens in each treatment were slaughtered and dissected immediately,the duodenum,jejunum and ileum were obtained and fixed in Bouin fixative solution for 24 h,then these tissue samples were made paraffin section(6 μm),stained with HE,observed and photographed with micro-photography system.The results were as follows.Compared with control group,the histopathological changes in each segment of small intestine appeared in each experiment group,and they became remarkable with the inoculation dosage of E.tenella oocysts.The accumulative E.tenella schizont in lamina propria and submucosa of jejunum and duodenum could be seen in chickens of experiment group Ⅴ.In each experiment group,the pathological lesions of jejunum were most obvious,secondly for duodenum,while the pathological changes of ileum were most slight.The results showed that the main parasitic sites and damage location of E.tenella were jejunum,next were duodenum and the end were ileum.The damage degree of small intestine caused by E.tenella were significantly correlated with the inoculation dosage of E.tenella oocysts.