Leukocytic response and composition of enteral microbiota in chickens fed a sage extract supplemented diet and infected with Salmonella Enteritidis PT4

The effects of sage on the enteral microbiota and leukocytic response of chickens challenged with Salmonella Enteritidis (SE) PT4 were studied. Chickens were divided into four groups: control, sage (S), SE and sage+S. Enteritidis (SSE). Groups S and SSE were fed sage extract (8.2 g kg^?1) for 21 days. Groups SE and SSE were challenged with SE (10⁸ CFU) on day 4. The administration of the sage extract to the SSE group confirmed the selective antibacterial activity on SE, and resulted in an increased number of leukocytes, lymphocytes, heterophils and phagocytic activity index at day 3 post-infection. In the early phase of the infection, there was a tendency to increase the numbers of CD3+, CD8+ and IgM+ cells in the SSE group. The later phase led to a decrease of IgM+, CD3+ and CD4+ cells, but an increase in influx of macrophages, which suggested their movement into inflammatory regions.