Efficacy of Acacia nilotica bark extract as an alternative to antibiotics in broilers challenged with Escherishia coli from 15 to 28 days

Abstract

The present experiment was conducted to compare the effect of Acacia nilotica bark extract and antibiotic on different biological parameters in broilers challenged with E. coli. Five hundred 2-week-old broiler chicks were divided into five treatments (Cont, NC, PC, AN-BE3, and AN-BE5) with ten replicates per treatment (10 chicks per replicate), and the experiment was extended over 2 weeks. All chicks, except that of Cont were challenged with E. coli (107 CFU/bird). Cont: basal diet only; NC: challenged with E. coli; PC: NC + Zinc Bacitracin 50 mg/kg diet; AN-BE3: NC + A. nilotica bark extract supplementation 0.3%; AN-BE5: NC + A. nilotica bark extract supplementation 0.5%. At the end of the experiment, one bird per replicate was selected randomly and slaughtered for sampling regarding blood biochemistry, intestinal morphology and cecal digesta. Weight gains in Cont, PC, and AN-BE5 were statistically similar but higher than that of NC. Similarly, feed conversion ratios in Cont, PC, and AN-BE5 were statistically similar but better than that of NC. The highest (p < 0.05) levels of blood glucose was observed in Cont (278.06 mg/dL) and the lowest in AN-BE5 (225.70 mg/dL). Concentrations of ALT and AST were significantly (p < 0.05) reduced in PC and A. nilotica bark extract supplemented groups than the other groups. Antioxidant status of birds in PC and A. nilotica bark extract supplemented groups was comparable and better than those of NC and Cont treatments. Villus heights in PC (1063.25 µm) and AN-BE5 (1061.63 µm) were similar but higher than those of Cont (1026.50 µm) and NC (1014.75 µm). In addition, counts of Coliform and C. perfringens were significantly reduced in PC and A. nilotica bark extract supplemented groups. A. nilotica bark extract could be an alternative to antibiotics in boilers challenged with E. coli.