Effect of diets with different fibrous contents on broiler gut microflora and short-chain fatty acid (SCFA) production

Fibers are dietary indigestible carbohydrates supplements which play an important role in avian digestive physiology and thus in production performances. In this study, we examined effects of diets on intestinal and cecal microflora and on production of SCFA in 21-day-old broilers. Diets differed in fibrous content (3, 4.5 or 6% of crude fiber, e.g. T1, T3, and T5, respectively) or in nature of fiber (T6 and T7). Five birds per diet were sacrificed at day 21 and microflora of their intestinal and cecal contents were analyzed using PCR-DGGE method with universal eubacterial 16S rDNA primers. In intestines, lactobacilli were the major bacterial population. However, several supplementary high intensity bands were found in the T5 diet. In ceca, profiles were rather constant, but some new bands appeared in the three experimental group diets T5, T6 and T7. Variations in SCFA were more significant in ceca samples. A significant increase in butyrate was observed in broilers from diets T5, T6 and T7. In contrast, acetate and lactate were the major SCFA observed for broilers on diet T1 and T3. In conclusion, these results provide insights into effect of fiber on the modulation of the broiler gut microbiota and on the SCFA production.