Influence of phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digestive tract measurements and gut morphology in broilers fed wheat-based diets containing adequate level of phosphorus

Abstract

1. The aim of the present study was to examine the influence of microbial phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digesta viscosity, digestive tract measurements and gut morphology in broilers fed on wheat-soy diets containing adequate phosphorus (P). The wheat-soy basal diet was formulated to contain 4.5 g/kg non-phytate P and the experimental diets were formulated by supplementing the basal diet with xylanase (1000 xylanase units/kg diet), phytase (500 phytase units/kg diet) or a combination of phytase and xylanase. 2. Supplemental phytase improved the weight gains and feed efficiency by 17.5 and 2.9%, respectively. Corresponding improvements due to the addition of xylanase were 16.5 and 4.9%, respectively. The combination of phytase and xylanase caused no further improvements in broiler performance. 3. Individual additions of xylanase or phytase resulted in numerical improvements in apparent metabolisable energy (AME), but the differences were not significant. The combination of the two enzymes significantly increased AME. Addition of xylanase and the combination of the two enzymes reduced the viscosity of digesta in all sections of the intestine. Phytase supplementation reduced digesta viscosity in the duodenum and ileum, but not in the jejunum. 4. Enzyme supplementation lowered the relative weight and length of the small intestine. Additions of xylanase and phytase reduced the relative weight of the small intestine by 15.5 and 11.4%, respectively, while the corresponding reductions in the relative length of the small intestine were 16.5 and 14.1%, respectively. The combination of phytase and xylanase had no further effects on the relative weight and length of the small intestine compared with the xylanase group. 5. The addition of phytase increased villus height in the duodenum and decreased the number of goblet cells in the jejunum compared with those on the unsupplemented basal diet. Xylanase supplementation tended to increase goblet cell numbers in the duodenum and decreased crypt depth in thejejunum. The combination of phytase and xylanase increased villus height in the ileum and crypt depth in thejejunum and ileum. 6. In summary, the present results showed that the addition of a microbial phytase, produced by solid state fermentation and containing significant activities of beta-glucanase and xylanase, was as effective as xylanase in improving the performance of broiler chickens fed on wheat-based diets containing adequate levels of P. Improved performance with enzyme supplementation was generally associated with reduced digesta viscosity, increased AME, and reduced relative weight and length of small intestine.

Maize replacement with sorghum and a combination of protease, xylanase and phytase on performance, nutrient utilization, litter moisture and digestive organ size in broiler chicken

“…On that account, the enzyme addition is likely to have minimized such a response in organs of the digestive tract due to less need for enzyme secretion, thus, reducing the size of the gizzard and small intestine (Wang et al 2005). Similar results were found by Wu et al (2004) and Zhu et al (2014) in diets supplemented with exogenous enzymes. Furthermore, a decrease in the relative small intestine weight is indicative of less cell proliferation and, consequently, less of a maintenance requirement for this organ (Adeola and Cowieson 2011).…”

The Effect of Thyme Extract on Growth Performance, Digestive Organ Weights and Serum Lipoproteins of Broilers Fed Wheat-Based Diets

“…In the present study, relative abdominal fat weight was reduced with ground wheat feeding compared to whole wheat. In contrast, Wu et al (2004) found no effect of whole wheat inclusion on abdominal fat weights. Other researchers have reported higher relative abdominal fat weight when whole wheat was included (Jones and Taylor, 2001;Nahas and Lefrancois, 2001).…”

Effects of xylanase and antibiotic supplementations on the nutritional utilisation of a wheat diet in growing chicks from genetic D+ and D− lines selected for divergent digestion efficiency

“…A decrease in the length of the intestine following supplementations is presumably related to more efficient and rapid digestion of nutrients (Marquardt, 1997). Accordingly, Wu et al (2004) reported that the addition of xylanase to ground wheat-based diets reduced the relative weight and length of the small intestine by 15.5% and 16.5%, respectively. In contrast, several authors (Brenes et al, 1993;Taylor and Jones, 2001) have previously indicated that xylanase supplementation did not significantly influence the relative weight and length of the intestine tract in chickens.…”