Effect of sage (Salvia officinalis L.) aqueous leaf extract on performance, blood constituents, immunity response and ileal microflora of broiler chickens

This study was aimed to evaluate the effect of different levels of sage (Salvia officinalis L.) aqueous leaf extract on performance, blood parameters, immunity response and ileal microflora in broiler chickens. A total of 300 male Ross-308 chicks were used until 42 days of age. Birds were randomly divided into five groups (three replicates with 20 birds per replicate) The treatments consisted of a control diet without feed additive and experimental diets supplemented with four levels of sage extract in drinking water (0, 100, 200, 300 and 400 ppm, respectively). Based on results, with the exception of significant differences between groups I and II regarding growth performance, in overall no differences among treatments were observed on body weight gain, feed intake and feed conversion ratio. Blood analysis showed that broilers fed different levels of sage extracts decreased (P < 0.05) plasma total cholesterol, triglycerides and low-density lipoprotein and increased high-density lipoprotein. A significant (P < 0.05) enhancement of the immunity response of broilers was observed when the dietary concentration of sage extract increased. Further, a significant (P < 0.05) bactericidal effect of sage extract was detected for Escherichia coli, whereas it was moderate for Lactobacillus. In conclusion, the positive effects sage extract on broilers immunity parameters and antibacterial activity were found to be strictly related with the dietary inclusion level.