The Effects of Rosemary (Rosemarinus afficinalis) and Garlic (Allium sativum) Essential Oils on Performance, Hematological, Biochemical and Immunological parameters of Broiler Chickens

Abstract

This study was conducted to investigate the effects of dietary inclusion of different levels of rosemary and garlic essential oils on performance, hematological, biochemical and immunological parameters of broilers. Seventy five one day-old commercial Ross 208 broiler chicks were assigned to one of five dietary groups (15 birds each). The control group received the basal diet. In addition to the basal diet, the four experimental diets included 100 mg rosemary oil /kg (R ), 200 mg rosemary oil /kg (R ), 100 mg garlic oil /kg 100 200 (G ) or 200 mg garlic oil /kg (G ). The data of growth performance indicated that supplementation of broiler 100 200 diets with rosemary oil had no growth-promoting effects. Garlic oil at 100 mg/kg exhibited the best performance. The data of hematological parameters implied a significant increase in packed cell volume in rosemary-treated groupswhile the mean values of hemoglobin demonstrated a significant increase in all treated groups. Significant increase in total leukocytic count was detected in all treated-groups with a marked increase in lymphocytic percent was seen in groups R and G. The main changes in blood biochemistry included a 200 200 significant decreased in serum activity of AST in garlic treated groups. Rosemary and garlic oils supplementation also led to increased serum levels of triglycerides, total cholesterol, low density- lipoprotein (LDL) and high-density lipoprotein (HDL) in broilers. Immunologically, there was a significant increase in phagocytic activity and phagocytic index in all treated groups but all dietary treatments failed to induce any significant effect on antibody titers at any age. Based on the results of this study, it could be concluded that garlic at a level of 100 mg/kg is recommended to be the best dietary treatment throughout improvement of performance of broilers and stimulation of innate immunity by increasing phagocytic capacity of heterophils.