The use of xylanase enzyme and inulin prebiotic supplementation to support broiler chicken production performance

Two isoenergetic (12.05 MJ/kg ME) and isonitrogenic (approximately 200 g/kg CP) basal diets were prepared using 670 g/kg of wheat with low fibre and/or high fibre contents. Each basal diet was divided into four portions: one remained as is and fed as control (C); the second was the C supplemented with 100 FXU/kg of a commercial xylanase (XYL); the third was the C plus 20 g/kg of inulin (IN) powder; and the fourth was the C supplemented with both XYL and IN at the same inclusion rates, resulting in a total of eight experimental diets. A study was conducted from 10 to 21 days of age involving 320 female Ross 308 broiler chickens. Each diet, in meal form, was fed <i>ad libitum</i> to eight pens, five birds each, following randomisation. Supplementary XYL increased dietary nitrogen corrected apparent metabolisable energy (AMEn) (<i>p</i> < 0.001), dry matter retention (DMR), daily feed intake (FI), weight gain (WG) and reduced feed conversion ratio (FCR) (<i>p</i> < 0.05). Dietary IN tended (<i>p</i> < 0.01) to increase WG and reduce FCR and dietary wheat did not have an impact on growth performance variables (<i>p</i> > 0.05). Birds fed XYL had reduced relative weight of the pancreas (<i>p</i> < 0.050) and there was XYL by IN interaction (<i>p</i> < 0.05) on relative weight of the caeca as it was greater for those fed XYL and IN. No other changes in relative weight of the gastrointestinal tract organs were observed (<i>p</i> > 0.05). Bird fed XYL or IN had greater (<i>p</i> < 0.05) butyric acid (BA) concentration in caecal content. Feeding XYL led to reduced acetic (AA) and propionic acid (PA) concentrations in caecal excreta (<i>p</i> < 0.05) and to a greater BA:AA ratio (<i>p</i> < 0.001). Dietary IN increased blood serum glutathione peroxidase (GSH-Px) (<i>p</i> < 0.05) and XYL increased concentration of hepatic coenzyme Q₁₀ (<i>p</i> < 0.05). The type of dietary wheat did not have an impact on any of the studied variables, suggesting that birds were able to tolerate the fibre contents in this study. It seems that both IN and XYL, can serve as feed enhancers that potentially may promote antioxidant status of birds and help poultry to cope with various stress factors during production. The study further confirms that supplementing wheat-based diets with XYL may be a strategy to mitigate the reduction in available energy and to increase nutrient availability in broiler diets.