Immunomodulatory Effects of Probiotic and Anticoccidial Treatments in Broiler Chickens

Four experiments evaluated the impact of probiotic administration on the immune response of broilers vaccinated with a live coccidiosis vaccine. Experiment one showed that probiotic administration increased heterophil and monocyte oxidative burst, and lymphocyte proliferation at multiple time points. In experiment two, probiotic + vaccine increased heterophil and monocyte oxidative burst on d 15 when compared with the negative controls. Overall, vaccine administration alone showed the highest response when compared to all other treatments. In the second trial, all birds were exposed to Eimeria oocysts in the litter and oral gavaged. The results showed that probiotic + vaccine resulted in greater heterophil and monocyte oxidative burst levels on d 14 and 28 when compared to the negative controls. Increases in lymphocyte proliferation were also seen in the probiotic + vaccine and probiotic alone broilers on d 14 among other treatments.

In experiment three, heterophil oxidative burst was increased (p <= 0.05) in the vaccine alone group, vaccine with probiotic group, and the ionophore with probiotic group, when compared to the negative control. Monocyte oxidative burst was increased (p <= 0.05) in the vaccine with probiotic group on d 36 and 43, compared to the negative control. Lymphocyte proliferation was greater (p <= 0.05) on d 22 and 36 in the ionophore with probiotic group, when compared to the negative control.

Experiment four showed that liver AVBD 2 gene expression elevated (p <= 0.05) in the probiotic + vaccine group relative to the probiotic alone group. Ileum AVBD 2 gene expression was not affected among any of the treatments was evaluated. Liver AVBD 9 was demonstrated to have higher (p <= 0.05) gene expression in the vaccine group when compared to controls. When AVBD 9 gene expression was evaluated in the ileum, a decrease (p <= 0.05) was observed in all treatments compared to the control group. These data suggest that simultaneous administration of probiotics during coccidiosis vaccination or ionophore treatment has the ability to modulate the immune response at varying time points.