Comparative efficacies of <i>Eimeria tenella</i> Apical membrane antigen-1 (<i>Et</i>ama-1) DNA and live attenuated oocysts vaccines against experimental infection with field isolate of <i>Eimeria tenella</i> 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®.