Combined endo-β-1,4-xylanase and α-l-arabinofuranosidase increases butyrate concentration during broiler cecal fermentation of maize glucurono-arabinoxylan

Abstract

Solubilisation of prebiotic arabinoxylooligosaccharides from complex arabinoxylans in e.g. maize by xylanases may be increased by addition of auxiliary debranching enzymes. In this study, the hydrolysis and fermentation of maize fibre was investigated in vitro using a xylanase and an α-l-arabinofuranosidase. Combining the enzymes induced a higher (P < .001) xylose solubilisation and higher (P < .05) butyrate production during in vitro fermentation of maize fibre with cecal broiler inoculum compared to applying enzymes separately after 48 h. Subsequently, fibre degradation and fermentation was investigated in ROSS 308 broiler chickens supplemented with the enzyme combination to test the effects on gut morphology and microbiota composition along with performance. However, to address the relevance of combining the enzymes in vivo, further full factorial studies using individual enzymes at lower dosages are needed. Birds were fed a maize/soy based diet with 100 g/kg maize DDGS and 50 g/kg rapeseed meal. Enzymes supplementation increased (P < .001) body weight (+5.4%) and improved (P < .001) feed conversion ratio (−5.8%) after 29 days compared to control birds. Non-starch polysaccharide analysis and confocal microscopy of jejunum digesta visualised and confirmed solubilisation of the insoluble maize (glucurono)arabinoxylan. Birds receiving enzyme supplementation had increased (P < .001) duodenum villi length (+120 μm) and reduced (P < .002) CD3 T-cell infiltration (−22.1%) after 29 days. Cecal butyrate levels were increased (P < .05) compared to controls. Although the microbiota composition was not significantly altered, numerical increases in cecal Ruminococcaceae and Lachnospiraceae genera were observed in birds supplemented with enzymes.