Effects of dietary enteric-released or pure benzoic acid on Ross 708 male broilers

An experiment was conducted to evaluate the effects of pure benzoic acid (PBA) or enteric-released benzoic acid (EBA) on performance, intestinal histology, apparent ileal digestibility (AID), cecal coliform and enterococci abundance, and litter moisture of broilers raised on used litter. Day-old male broiler chicks were assigned to control (Con), nontreated diet; positive control (BMD), Con + 50 ppm bacitracin methylene disalicylate; PBA, Con +1,000 ppm of PBA; EBA, Con +330 ppm of EBA. From 0 to 28 and 0 to 42 d, BMD outperformed the Con in either BW gain (BWG) or mortality corrected FCR (FCRm) (P ≤ 0.05). Over 0 to 28 d, EBA and PBA improved BWG and FCRm compared to the Con (P ≤ 0.05). When the entire 0 to 42 d period was considered, EBA improved both BWG and FCRm in comparison to Con (P ≤ 0.05). Supplementation with EBA and PBA resulted in inconsistent responses in duodenum and jejunum morphology; specifically, PBA decreased 28 d duodenal crypt depth and increased villus height to crypt depth ratio, while EBA decreased 28 d jejunum crypt depth (P ≤ 0.05). There were no differences in AID or cecal coliform counts (P > 0.05) due to treatment. However, PBA significantly reduced enterococcus counts at 42 d by 0.48 Log₁₀ CFU/g compared to CON. These results suggest that EBA can increase BWG and decrease FCRm, while PBA performance was similar to CON. Additionally, benzoic acid decreased crypt depth, with the response being tissue-specific depending on the form of benzoic used.