Investigation into the potential of using UV-treated sporulated oocysts of Eimeria tenella as a local solution to immunization of chickens against caecal coccidiosis

Djemai, S; Mekroud, A; Hide, G; Khelifi, D; Bellil, I

Abstract

In this study, we aim to evaluate the immune response of chickens to UV-treated sporulated oocysts as a means of protection against caecal coccidiosis caused by field strains of Eimeria tenella. Two groups of chicks were immunized using prepared UV-treated oocysts of E. tenella and challenged at day 20 post hatching. The first group was immunized only once at day 1 post hatching, the second group was immunized twice (day 1 and day 8 post hatching). Two non-immunized control groups were used: the first group was challenged with E. tenella, while the second group remained uninfected. The effectiveness of immunization on production and animal health was evaluated by the following criteria: body weight, feed conversion ratio, blood in faeces, mortality, lesion scores and oocyst output. The two immunized groups showed a significantly better performance in body weight, weight gain and lesion scores than the non-immunized group. However, all three groups performed significantly worse than the unchallenged group. The mortality of the non-immunized infected group was high (70%) while mortality in both immunized and unchallenged groups of chickens was significantly lower (range 2.2 to 4.4%) than the infected group (p < 0.05). The production of oocysts in faeces, post-infection, was significantly higher in the non-immunized group compared to the immunized group (p < 0.05) and both were significantly higher than the uninfected group (p < 0.05). In conclusion, immunization by prepared UV-irradiated oocysts is effective in stimulating at least a partial protective immunity in immunized chickens against caecal coccidiosis.

• Journal Article Type: Article
• Acceptance Date: Dec 24, 2022
• Online Publication Date: Jan 7, 2023
• Publicly Available Date: Jan 7, 2024
• Journal: Journal of Parasitic Diseases
• Print ISSN: 0971-7196
• Electronic ISSN: 0975-0703
• Publisher: Springer Verlag
• DOI: https://doi.org/10.1007/s12639-022-01562-7
• Keywords: UV-treated; Oocysts; Eimeria tenella; Coccidiosis; Immunity
• Publisher URL: https://doi.org/10.1007/s12639-022-01562-7