Xylo-oligosaccharides display a prebiotic activity when used to supplement wheat or corn-based diets for broilers

Area of Science:

• Animal Science
• Microbiology
• Nutritional Biochemistry

Background:

• Exogenous β-1,4-xylanases enhance poultry diet nutritive value, potentially via microbial routes producing prebiotic xylo-oligosaccharides (XOS).
• Understanding the precise mechanism of enzyme action and the role of XOS in poultry gastro-intestinal tracts is crucial for optimizing feed formulations.

Purpose of the Study:

• To investigate the effects of xylo-oligosaccharides (XOS) on broiler performance fed wheat or corn-based diets.
• To explore the microbial mechanisms underlying XOS action in the avian gastro-intestinal tract.
• To compare the efficacy of XOS with exogenous β-1,4-xylanase in improving diet nutritive value.

Main Methods:

• Three experiments were conducted to assess broiler performance (weight gain, overall performance) with diets supplemented with XOS or β-1,4-xylanase.
• Dietary inclusion rates of XOS were varied (0.1, 1, and 10 g/kg) across experiments.
• Microbial populations in the upper gastro-intestinal tract were analyzed to identify shifts associated with XOS supplementation.

Main Results:

• XOS supplementation significantly increased weight gain in broilers fed wheat-based diets (P = 0.08).
• Dietary XOS and β-1,4-xylanase improved the nutritive value of wheat-based diets over a 42-day trial.
• Performance improvements were associated with shifts in upper gastro-intestinal microbial populations; XOS also improved corn-based diet performance, though less effectively at higher inclusion rates.

Conclusions:

• The performance-enhancing effects of β-1,4-xylanases in poultry may be attributed to their production of prebiotic XOS rather than solely arabinoxylan degradation.
• XOS demonstrate prebiotic potential at very low inclusion rates, challenging the notion of substantial substrate fermentation for prebiotic effects.
• XOS can improve broiler performance independently of endosperm cell wall integrity, suggesting alternative mechanisms of action beyond direct enzymatic degradation.