Efficacy of a Synergistic Blend of Organic Acids and ß-1,4 Mannobiose on Cecal Salmonella Counts and Growth Performance in Salmonella Challenged Broiler Chickens: A Meta-Analysis

SIMPLE SUMMARY: Salmonella may cause serious diarrhea in consumers of poultry products. Control of Salmonella in poultry with antibiotics has caused antimicrobial resistance issues. Salmonella can colonize the gut of chickens, meaning that an in-feed solution may prevent infection. A synergistic blend containing organic acids and ß-1,4 mannobiose as main ingredients were developed to reach different parts of the gut. It was hypothesized that this synergistic blend decreases Salmonella contamination of chickens. Several, non-published, studies have been performed to test the effect of this synergistic blend in chickens infected with Salmonella. The results of these studies were combined into a large meta-analysis to draw conclusions regardless of study design and geographical location. This state-of-the-art statistical method did show that feeding the synergistic blend to chickens could decrease Salmonella in comparison to a control diet. This decrease was most clear during the first 14 days after initiation of the Salmonella infection. In addition, the birds did grow more efficiently when the synergistic blend was fed. ABSTRACT: This study aimed at investigating the effect of a functional synergistic feed additive blend, containing organic acids and ß-1,4 mannobiose, on cecal Salmonella counts and growth performance of broiler chickens. A meta-analysis combining 13 individual studies, executed in Salmonella-challenged broilers comparing a control diet with and without the synergistic blend, was performed. Cecal Salmonella colonies and overall growth performance were measured. Raw data from all studies were combined and analyzed using PROC MIXED in SAS, taking the within and between-study variation into account. In the first 14 days post-inoculation (DPI), cecal Salmonella was reduced by 0.429 log CFU/g (p = 0.011, n = 10 comparisons from five studies) when feeding the synergistic blend compared to the control group. During 15–34 DPI, the overall means were not different between treatments (0.069 log CFU/g; p = 0.519, n = 12 comparisons from eight studies). The feed conversion ratio was improved when feeding the synergistic blend compared to the control diet (1.474 vs. 1.482, respectively; p = 0.002). In conclusion, feeding a synergistic blend, containing organic acids and ß-1,4 mannobiose amongst other ingredients, reduced cecal Salmonella counts during the first 14 DPI and improved growth performance of Salmonella challenged broilers compared to a control diet.