Performance and morphometry of the intestinal mucosa of laying hens fed diets containing xylanase

KMR de Souza,C de G Kikuchi,VC Caetano,DE de Faria,TT dos Santos,RB Araújo,DT Nakashima,MI Sakamoto

doi:10.1590/1516-635x1603241-248

KMR de Souza, C de G Kikuchi + Show 6 more

Open Access

https://doi.org/10.1590/1516-635x1603241-248

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Abstract

The objective of this study was to evaluate the effect of dietary energy level reduction and xylanase inclusion on the performance and on intestinal mucosa morphometry of two- to six-week-old laying hens. In total, 400 Hy-line W36 laying hens were distributed according to a completely randomized design in 2 x 2 factorial arrangement (energy level x inclusion of xylanase), totaling four treatments with 10 replicates of 10 birds per experimental unit. The following treatments were evaluated: positive control (balanced diet); positive control + xylanase; negative control (diet with of 100 kcal ME reduction /kg); negative control + xylanase. Body weight, weight gain, feed conversion ratio, uniformity and livability were not influenced by diets with metabolizable energy reduction and xylanase inclusion; however, the addition of xylanase to the diets resulted in shallower crypts depth and greater villus:crypt ratio in the ileum. The energy reduction of the diet associated with the supplementation of xylanase did not influence performance, but increased the feed intake of 2- to 6-week-old laying hens and increased villus height in the ileum of 6-wk-old hens. Xylanase reduces crypt depth in the ileum of 6-week-old hens.

Highlights

IntroductionLayers have become more productive birds, presenting lower body weight and lower feed intake
Due to genetic improvement, layers have become more productive birds, presenting lower body weight and lower feed intake
The mash diets were based on corn and soybean meal and were formulated to meet the requirements recommended by Rostagno et al (2005), except for the energy level of the negative control diets (Table 1)

Summary

Introduction

Layers have become more productive birds, presenting lower body weight and lower feed intake. The greatest challenge today is to supply the higher nutritional requirements of modern layers. The rearing phase is considered the most sensitive. Adequate nutritional management during growth determines subsequent layer performance. In this context, alternatives have been sought for the formulation of more effective and economical feeds, considering that the diet accounts for the highest cost in poultry production. Improvements in energy efficiency should be directed for maximum nutrient utilization when traditional and alternative feedstuffs are included in the feed (Jaroni et al, 1999)

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