The effect of olive leaf and oregano powder on performance, blood parameters and ileal microflora of broiler chickens

Olive is an evergreen tree with antibacterial properties and showed beneficial effects on the microbial flora of the digestive tract. Also, oregano plant with antioxidant properties can improve the feed conversion ratio. This experiment was conducted to investigate the effects of olive leaf and oregano powder on performance, blood parameters and ileal bacteria population of broiler chickens. A total number of 400 male and female Cobb 500 broiler chicks in a completely randomized design with 5 treatments, 4 replicates and 20 chicks per each were used. Birds were kept under same condition during the first week of rearing period. From 8 days of age until the end of rearing period, each of experimental groups was fed with one of the following diets: 1- basal diet without additive (control) 2- diet containing 50 g/ton erythromycin 3- diet containing 0. 5% olive leaf 4- diet containing 0. 5% oregano 5- diet containing 0. 5% mixture of olive leaf and oregano. The management conditions of all groups were the same throughout the breeding period. At the end of the experiment (42 days), two chicks of each replicates were selected and slaughtered. Statistical evaluation was performed using SAS program. The results indicated that although supplementation with olive leaf, mixture of olive leaf and oregano as well as antibiotic significantly improved feed conversion ratio during 8-21 days of age compared to control group, but performance parameters (feed intake, body weight gain and feed conversion ratio) of broilers during 8 to 42 days of age were significantly not influenced by experimental treatments. The highest and the lowest levels of blood HDL were observed in olive leaf and mixture of olive leaf and oregano and oregano groups, respectively (p<0. 05). All additives significantly increased ileum lactobacillus and decreased E. coli count compared to the control group (p<0. 05). In conclusion, the results showed that dietary addition of oregano and olive leaf can beneficially influence some blood parameters and also ileal bacteria of broilers.