The effect of infection with mixed Eimeria species on hematology and immune responses following Newcastle disease and infectious bursal disease booster vaccination in broilers

摘要

Background: Coccidiosis is an important parasitic disease of chickens, causing high mortality and morbidity. This morbidity is believed to be correlated with altered population dynamics of blood cells and immunocompromisation. Objectives: This study investigated the effects of mixed Eimeria species (viz., tenella , maxima , acervulina and necatrix ) infection on hematology and immune responses following Newcastle disease (ND) and infectious bursal disease (IBD) booster vaccination in broilers. Animals and methods: One-day-old broiler chicks (Hubbard; n = 200) were divided into two equal groups A and B. On day 16, group A was infected orally with Eimeria species (7 × 10~(4) sporulated oocysts), whereas group B served as control. Both groups were analyzed for hematological parameters on post-infection days 6–8. Sera from both groups were analyzed for antibody titers against ND and IBD vaccines. On day 8 post-infection, lymphoid organs were also examined. Results: Significantly lower ( P 0.05) levels of plasma proteins, globular volume, hemoglobin concentration, packed cell volume, total erythrocytes, mean corpuscular volume and mean corpuscular hemoglobin concentration were found in infected chickens compared with non-infected control chickens. In addition, the infected group exhibited significantly increased ( P 0.05) numbers of different leukocytes. Infected chickens also showed significantly lower antibody titers against ND and IBD with decreased relative organ weights of all lymphoid organs except spleen. Conclusion and recommendations: Mixed species of Eimeria adversely affected the hematology and immune efficiency of broilers. Thus, inexpensive immune potentiators and hemotonics along with appropriate anti-coccidial medications are suggested to avoid the complications and subsequent economic losses.