Effect of Thyme and Ziziphora essence on performance, microbial population and immune response of broiler chickens

This experiment was conducted to evaluate effects of different levels of Thyme or Ziziphora essence on performance,microbial population and immune response of broiler chickens. Four hundred and twenty day-old male chicks (Ross 308) were randomly distributed in seven dietary treatments of four replicates with 15 chicks/pen in a completely randomized design. Treatments were 50, 100 and 150 mg/kg diet of Thyme or Ziziphora essence and a non-essence diet as a control group. Based on the results, inclusion of 50 mg/kg of Ziziphora resulted in higher weight gain than control treatment at the end of experiment (P<0.05). On the other hand, feed intake was significantly increased with 50 mg/kg of Thyme and Ziziphora essence (P<0.05).At the end of experiment, no significant differences were shown between treatments in FCR.Thyme in 150 mg/kg and Ziziphora in 50 mg/kg indicated the highest EPI (P<0.05). Thyme at 100 and 150 mg/kg levels increased the proportion of lactobacilli and reduced intestinal colibacilles (P<0.05). Based on the results, different levels of Thyme compared to Ziziphora essence showed stronger effects on the humeral and cellular immune responses of broilers.