Efficiency of a prebiotic and a plant extract alone or in combination on broiler performance and intestinal physiology
A 36-d trial was conducted to evaluate two potential alternatives to antibiotic growth promoters in broilers. The products tested were a prebiotic (PROFEED®) and a plant extract (XTRACT™). Ross male broiler performance and digestive tract function responses were studied. To evaluate the effect of these potential alternatives alone or in combination, seven diets were tested: positive control avilamycin 10 ppm (PC); negative control antibiotic-free (NC); NC + PROFEED® 600 ppm (P); NC + XTRACT™ 100 ppm (X); NC + PROFEED®/XTRACT™ 600/100 ppm (XPH); NC + PROFEED® /XTRACT™ 450/75 ppm (XPM); NC + PROFEED®/XTRACT™ 300/50 ppm (XPL). From 22 to 36 d of age, body weight gain (BWG) was improved by P, X, and XPM compared with NC (P < 0.05). Throughout the trial, broilers fed PC, P, X and XPL had a better feed conversion ratio (FCR) than those fed NC (P < 0.1). No relevant negative effect was observed for the parameters relative to the digestive tract function: ileal histomorphometry, anaerobic sulphite-reducing bacteria count (ASR), intestinal and caecal pH, caecal volatile fatty acids production (VFA) and litter score (LS). With the higher mixture dose (XPH), no improvement in broiler performance was observed, suggesting no synergistic effect of the two additives. Key words: Broiler, antibiotic growth promoter, plant extract, prebiotic