The effects of Thymus vulgaris L., Echinacea purpurea (L.) Moench., Allium sativum L. extracts and virginiamycin antibiotic on intestinal microflora population and immune system in Broilers

The present study was designed to evaluate comparison of the effects on the intestinal microflora population and immune system of broilers of three commercial herbal extracts and virginiamycin antibiotic. A total four hundred and eighty 1-day old male broiler chicks were assigned to the basal diet (control) and basal diet supplemented with 150 ppm virginiamycin, 0.1% extract of thyme (Thymus vulgaris L.), coneflower (Echinacea purpurea (L.) Moench.), garlic (Allium sativum L.) and blend of extracts with the same dose. The colony forming units of Escherichia coli in digesta of ileo-cecum in the blend group showed a significantly lower number compared with control group. However, there was no difference in E. coli counts between blend group and others except control. The lactic acid bacteria counts in the thyme group increased compared with other groups except coneflower (p<0.05). Relative weights of immune organs (spleen and bursa of Fabricious) as two immune indexes were compared among different groups. Relative weight of bursa of Fabricious in the Garlic group showed a significantly increase compared with other groups, but relative weight of spleen was unaffected by treatments. Cutaneous basophils hypersensitivity response (to phytohemagglutinin injection) and antibody responses to sheep red blood cells were higher in coneflower group (p<0.05). Antibody responses to Newcastle vaccine (Lasota) was unaffected by treatments but coneflower group improved antibody levels (p>0.05).