Exogenous dietary xylanase ameliorates viscosity-induced anti-nutritional effects in wheat-based diets for White Pekin ducks (Anas platyrinchos domesticus)
British Journal of Nutrition
Nutrient utilisation and growth performance responses of White Pekin ducks (Anas platyrinchos domesticus) offered diets containing lowor high-viscosity wheat supplemented with xylanase were investigated in two studies. In Expt 1, six diets consisting of low-viscosity wheat or high-viscosity wheat supplemented with 0·0, 1·5 or 3·0 g xylanase (2590 units/g)/kg diet were used in a true metabolisable energy (TME) bioassay with eight 8-week-old ducks per diet group. In Expt 2, eight pens of ten
... ld ducks per pen for each of six wheatbased diets arranged in a 2 £ 3 factorial of low-viscosity or high-viscosity wheat and 0·0, 1·5 or 3·0 g xylanase/kg were used in a 42 d growth study. High-viscosity wheat depressed (P, 0·001) TME and xylanase supplementation improved (P,0·001) TME, more so for high-viscosity than low-viscosity wheat. Xylanase supplementation of the high-viscosity wheat-based diet improved (P, 0·05) weight gain and gain:feed ratio by 13 and 12 % respectively. There was no weight gain or gain:feed ratio response to xylanase supplementation of the low-viscosity wheat-based diet. Xylanase supplementation reduced (P, 0·001) the viscosity of duodenal and ileal digesta for highviscosity but not low-viscosity wheat-based diets. Ileal digestibilities of nutrients and energy were higher (P, 0·001) for low-viscosity than high-viscosity wheat-based diets; xylanase supplementation improved (P, 0·05) energy, fat, N and starch digestibilities. Given that xylanase supplementation of high-viscosity wheat assuaged its anti-nutritional effect, it is surmised that digesta viscosity plays a role in antinutritional effects in wheat-based diets for ducks. White Pekin ducks: Wheat: Xylanase: Viscosity: Nutrient digestibility * Corresponding author: Professor Olayiwola Adeola, fax þ 765 464 9346, email email@example.com Abbreviations: TME, true metabolisable energy; TMEn, true metabolisable energy corrected for nitrogen.