Study On Biology Of Eimeria Anseris

Coccidiosis in domestic goslings is an important protozoan disease caused by several coccidia worldwide. Currently, 16 species of the family Eimeriidae belonging to 3 genera have been described in the world, and 11 species belonging to 2 genera in China. The pathogenicity of Eimeria truncata and Eimeria anseris is highest among the 16 species. Study on coccidiosis in domestic goslings mostly were focused on surveys of coccidian species, and the life cycles and pathogenicity of many species have rarely been reported. So in the present study, the life cycle, pathogenicity, histopathology and therapy of E anseris in domestic goslings were studied.1 Isolation and Biological Characterization of Eimeria anserisA pure species was isolated and found to be Eimeria anseris (Kotlan, 1932). The oocysts are shaped like a sphere surmounted by a truncate cone; with a smooth, colorless, 1-layered wall; with a residuum and a micropyle; without a polar granule. Oocysts mean 19.37μm×16.06μm., and the shape index is 1.20. The sporocysts are ovoid, with a stieda body, and mean 9.09um×6.83μm. The prepatent period is 168 h～173 h, the patent period is 107 h～118 h, and the minimum sporulation time is 55 h. The difference of reproducibility infected with different dose oocysts was significant(P < 0.05).2 Study on the Pathogenicities of Eimeria anserisTo study the pathogenicities and pathogology, eighteen-day-old Tianshan domestic goslings were infected with 3×10~4 or 0.5×10~4 the oocysts of E.anseris per bird, assessed by clinical symptom, gross pathology, and pathological histology, average weight gain, lesion score and mortality. The results showed that: the clinical symptom and gross pathology were similar in birds infected with different dose oocysts. In all infected groups, the weight gains were significantly different from that of the control group(P < 0.05)and the lesion score were terribly different from that of the control group(P < 0.01). The infections with 3×10~4 and 0.5×10~4 sporulated oocysts per bird caused a mortality of 10 %～30 % and 60 %～90 %, respectively. It showed that E.anseris is markedly pathogenic in domestic goslings.3 Studies on Endogenous Development and Histopathology of E.anseris...