Studies on Coccidia in Experimental Infection with Eimeria spp in Rose-Cobb Broiler Chicken

The experimental completely randomized design was conducted on poultry coccidiosis of Rose-Cobb breed of one hundred broiler chicken from November 2015 to April 2016 in the Faculty of Veterinary Medicine, University of Gondar. The experimental animals (n=100) were randomly allocated into four equal groups, group one (G-I), group two (G-II), group three (G-III) and group four (G-IV) with 25 chickens in each group. The G-I, G-II, and G-III were treatments groups challenged by different Eimeria sporulated oocysts, while G-IV served as the control group. In this study, the infective dose of E. tenella (G-I), E. acervulina (G-II) and mixed Eimeria spp (G-III) was 2x104 sporulated Eimeria oocyst inoculated orally at three weeks of age in broiler chicken and subsequent alterations in different haematological constituents were evaluated at interval of 5, 7 and 9 day of post inoculation. The Eimeria species identified from the natural infected chickens were E.tenella, E. acervulina, E. maxima and E. necatrix. E.tenella was more pathogenic than E.acervulina and mixed Eimeria spp. Oocyst counts per gram of faeces in pure (E. tenella and E. acervulina) and mixed Eimeria spp. infection showed marked increase from the 5 to 8DPI. Pure single infection of E. acervulina and E. tenella showed highest oocyst excretion on 6 DPI (62, 395 oocyst/g of faeces) and 7 DPI (86, 535 oocyst/g of faeces) respectively. Whereas mixed Eimeria spp. infection reached a maximum oocyst count of 51, 270 oocyst/gm of faeces on 7 DPI.