野外鶏の腸組織におけるコクシジウム寄生の諸相

抄録

This investigation was carried out in order to know the morphological features ofcoccidia in the intestinal tissue of field chickens. The materials used for it consisted of96 birds of various breeds ranging from 20 days to more than one year of age. Of them, 56 birds were affected concurrently with so-called avian leukosis and 1 bird with Gumborodisease. In principle, the duodenum, jejunum, ileum, cecum and rectum were examinedhistologically in each bird.In consequence, 17 birds were infected mainly with Eimeria acervulina (Table 1), 32 mainly with E. tenella (Tables l -3), 29 mainly with E. necatrix (Tables 2, 4), and 18mainly with E. maxima (Table 5). Twenty-three of all the birds harbored one or two ofthe species of Eimeria mentior?ed above in addition.Parasites in various sexual phases of development were observed within the epi-thelial cells of the intestine (duodenum, jejunum, ileum and cecum), and those invarious asexual phases of development in the lamina propria of the intestine, which maybe a matter of course. As to the morphology of the life cycle of Eimeria, no discrepancieswere found out between the findings obtained by the present authors and those fromexperimental studies by TYZZER6) and TYZZER et aI.7).The identification of coccidial species parasitizing the intestinal tissue will not alwaysbe difficult, if the morphology of the parasites in various stages of development and thelocalization of them in the intestinal tissue and within infected cells are understoodthoroughly.Furthermore, the following findings were pointed out in this study. Birds whichwere accompanied by another species of Eimeria in addition were comparatively numer-ous. A large number of birds had a small number of developing parasites. Retrogres-sive schizonts were fairly frequently found out. These results must be taken into con-sideration in the investigation of coccidial infection in field chickens.