Effects of a Commercial Beta-Mannanase Product on the Performance, Intestinal pH, and Digesta Viscosity of Pekin Ducks

Abstract

SUMMARY An experiment was performed to investigate the effects of a commercial β-mannanase product in duck diets containing 10% guar hull fraction. The experiment consisted of a factorial arrangement of 2 levels of β-mannanase (0% and 0.1%) and 2 levels of guar hull (0% and 10%). Addition of guar to the diets significantly reduced body weight, weight gain, feed consumption, and productive index at day 21. Addition of guar significantly increased feed:gain 0–7 d and 0–14 d. There were no significant effects of guar level on digesta pH except in the gizzard where pH was significantly reduced. Enzyme addition significantly increased body weight, weight gain, feed consumption, and productivity index. Inclusion of β-mannanase resulted in a significant reduction in feed:gain 0–7 d, 7–14 d, and 0–14 d. Digesta pH was significantly increased in ducks fed diets with β-mannanase. A significant interaction between guar and enzyme treatments existed for digesta viscosity of the jejunum and ileum. In diets without guar, the addition of β-mannanase did not significantly impact digesta viscosity in either intestinal segment. In diets containing guar, enzyme supplementation significantly decreased digesta viscosity. The addition of β-mannanase provided for improvements in performance, digesta pH, and viscosity regardless of guar inclusion rate; however, the improvements in digesta viscosity were of greater scale in diets containing guar.