Comparative efficacies of Eimeria tenella Apical membrane antigen-1 (Etama-1) DNA and live attenuated oocysts vaccines against experimental infection with field isolate of Eimeria tenella in broiler chickens

Abstract

This study evaluated the efficacy of vaccination of broiler chickens against coccidiosis using Eimeria tenella (EtAMA-1) DNA vaccine in comparison to vaccination using live polyvalent oocyst vaccine (Livacox®). Forty-day-old broiler chicks were randomly assigned into 4 groups; group 1 birds were unvaccinated uninfected control, group 2 were unvaccinated infected, group 3 were vaccinated with 0.1ml containing100μg EtAMA-1 vaccine plasmid on the thigh muscle at days 14 and a booster at days 21 of age, while at 10 days old, group 4 birds were administered 0.2ml of Livacox®. At 28 days of age, all chickens except group 1 were inoculated with 1 × 10⁴ sporulated oocysts of the E. tenella and evaluated for weight gain(WG), oocysts production (OP), lesion scoring (LS) and anti coccidial index (ACI). Higher WG (116±43.89 g) were recorded in group 4 compared to group 3 (110±29.15 g), although, statistically insignificant but was significant (p <0.05) when compared with group 2 (40±12.25 g). OP was significantly (p <0.05) higher in group 2 (1.3x105±11.00) compared to groups 3 and 4 (0.58x10⁵±18.00 and  0.44x10⁵ ±42.36) respectively. Both vaccines significantly (p <0.05) reduce the effects of E. tenella on LS (1.4 ± 0.6 and 1.0 ± 0.62) for groups 3 and 4 respectively compared to the unvaccinated group 2 (4.0 ± 0.00). Higher ACI was observed in groups 3 and 4 (177 and 180) respectively compared to group 2 (170). Conclusively, EtAMA-1 DNA vaccination ameliorated the effects of E. tenella infection in broiler chickens comparable to Livacox®.