A Study on the Efficacy of Dietary Supplementation of Organic Acid Mixture in Broiler Chicks

This experiment was conducted to investigate the effects of dietary supplementation of organic acid mixture on growth performance, cecal microflora, blood characteristics and immune response in broiler chicks and to prove the possibility of organic acid mixture as an alternative to antibiotics growth promotor. A total of four hundred eighty, 1-day-old male broiler chicks (Ross×Ross 308) were randomly divided into 4 groups with 4 replicates of 30 birds each. The treatments were NC (free antibiotics), PC (basal diet with virginiamycin 10 ppm and salinomycin 60 ppm), 0.3% organic acid, and 0.5% organic acid. The final body weight and body weight gain were significantly higher in organic acid 0.5% than NC (P less than 0.05). The feed conversion ratio in all treated groups were significantly improved as compared to that of NC (P less than 0.05). The carcass rate and relative organs weight were not significantly difference among the groups. The relative weight and length of small intestine in PC were significantly decreased than the other groups. The numbers of cecal coliform bacteria and Salmonella in all treated groups were significantly lower than NC (P less than 0.05). The number of cecal lactic acid bacteria was not different among the groups. No significant differences among the groups were observed in the contents of total cholesterol, triglyceride, blood urea nitrogen (BUN), albumin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in blood serum. The contents of total protein and globulin in blood serum of PC and organic acid treated groups were significantly increased as compared to those of NC (P less than 0.05). Therefore, albumin:globulin ratio of PC and organic acid treated groups was significantly lower than NC (P less than 0.05). The total white blood cell (WBC), heterophil, lymphocyte, and stress indicator (heterophil:lymphocyte ratio) were not significantly different among the groups. No significant difference was observed on the expression rate of splenic cytokines mRNA in organic acid treated groups compared to the control. Consequently, supplemental organic acid mixture improved the growth performance, and influenced positive effects on the intestinal microflora by inhibiting the growth of harmful bacteria without any adverse effects on relative weights of organs and blood biochemical parameters in broiler chicks.