The Effects of Rosemary (Rosemarinus afficinalis) and peppermint (Mentha piperita) on Performance, Hematological, Biochemical and Immunological parameters of Broiler Chickens

Objectives: The concerns about antibiotic residues and antibiotic resistance have aroused greatcaution in the usage of antibiotics. The barnning of the use of antibiotics as feed additives hasled toinvestigations of alternative feed additives in animal production. As one of the alternatives, herbal extracts such as peppermint and rosemary are already being used as feed supplement for improving growth performance and their varying degrees of antimicrobial activity.Materials Methods: The objective of this study was to investigate the effects of peppermint and rosemary on performance, hematological, biochemical and immunological parameters of broiler chickens. Five groups of broiler chickens were used (10 birds in each groups).The control group received the basal diet.In addition to the basal diet, the four experimental diets included rosemary oil 100mg/kg (R1) and200mg/kg (R2), peppermint oil100mg/kg (p1) and200mg/kg (p2).Body weights were measured at days of 1, 14,28 and 42, feed intake was measured for different periods and FCR was calculated accordingly. At 18 and 28 blood samples were taken for measuring antibody titers and at 42 for biochemical and hematological analysis.Results Conclusion: The data of growth performance indicated that R1 and R2 had no growth-promoting effects. Peppermint oil at 100 mg/kg exhibited the best performance. Hematological parameters implied a significant increase in packed cell volume in rosemary-treated groups. The mean values of hemoglobin and leukocyticlymphocytic count demonstrated a significant increase in all treated groups. The main changes in blood biochemistry included significant decreased in serum activity of AST in peppermint treated groups. Rosemary and peppermint oils supplementation also led to increased serum levels of triglycerides, total cholesterol,(LDL) and (HDL).Immunologically, there was a significant increase in phagocytic activity and phagocytic index in all treated groups. Based on the results, it could be concluded that 100 mg/kg peppermint is recommended to be the best dietary treatment throughout improvement of performance of broilers and stimulation of innate immunity.