Effects of xylanase and phytase on digestion site of low-density diets fed to weaned pigs

Abstract

The effects of xylanase and phytase supplementation on energy digestibility, site of nutrient digestion, and pH content in the gastrointestinal tract (GIT) and on growth performance were studied in diets with reduced nutrient specifications fed to weaned pigs. The experiment was designed as a 2 x 2 factorial plus a positive control diet containing14.65 MJ digestible energy (DE)/kg, 0.65% total phosphorous (P), and 0.80% calcium (Ca). Phosphorous and Ca contents were reduced by 10% and the DE content by 0.62 MJ/kg in the other 4 diets. Weaned pigs (8.6 ± 0.5 kg initial body weight)were fed 1 of 5 diets for 21 d. Feeding a nutrient reduced diet lowered total tract energy digestibility. Xylanase and phytase improved the total tract DE content of the negative control diet (NC). Xylanase improved energy digestibility of NC in the mid jejunum and over the total tract by 63.0 and 4.6% respectively. Phytase improved the DE content of NC by 0.64 MJ/kg. Feeding a nutrient reduced diet tended to reduce the pH content of the upper small intestine (SI), and phytase raised the pH content of the upper mid SI. Overall phytase improved body weight (BW) and the average daily gain (ADG) of NC. Xylanase and phytase improved total tract DE content and growth performance of weaned pigs fed nutrient reduced diets. Phytase inclusion led to a faster return to alkaline conditions in the upper SI. Exogenous enzymes can be used to improve digestibility of nutrient-reduced diets based on wheat and millrun for weaned pigs. © 2015 Fundacion CIPAV. All rights reserved.