Abstract
An experiment was conducted using Bovans White layers to investigate the effects of 30% whole-wheat inclusion in a standard layer diet supplemented with xylanase, on laying performance, digestive organs and ileal mucosa development. Three dietary treatments were used: 1) control diet (30% ground wheat); 2) 30% whole wheat; 3) whole wheat+wheat xylanase. Xylanase was added to whole wheat at 150g/ton. Including the pre-experimental period the trial lasted for 13 weeks. Xylanase supplementation to whole wheat significantly (P<0.05) improved egg production and feed conversion rate compared to the ground wheat and whole wheat fed groups. Gizzard pH was not affected by dietary treatments, while whole wheat feeding significantly (P<0.05) reduced jejuno-ileal pH and increased gizzard and jejuno-ileal viscosity compared to the ground wheat fed and xylanase supplemented groups. Proventriculus, gizzard, duodenum, jejunum, ileum, caecum, colon and liver weights were not significantly affected by dietary treatments. Feeding whole wheat w/wo xylanase supplementation significantly (P<0.05) increased crypt depth but did not affect lamina muscularis mucosae thickness.