Influence of β-galacto-oligosaccharide on growth performance and components of intestinal barrier in broilers during heat stress

S Ashraf,S Masood,A Sikandar,S Yousaf,H F Rehman,H Zaneb,M M Usman,H Rehman

doi:10.4314/sajas.v47i5.4

Abstract

This study aimed to investigate the influence of β-galacto-oligosaccharides (β-GOS) on growth performance, organ development and intestinal microarchitecture of broilers during heat stress. Day-old chicks (n = 125) were divided into five groups. The control or thermoneutral zone group (TNZ) was raised under standard management until the 35th day. Four groups were exposed to cyclic heat stress (35 °C 8 h/d) from the 22nd to the 35th day. The TNZ and heat stress control (HSCT) groups were fed a corn-based diet and HS + 0.1% β-GOS; HS + 0.2% β-GOS; and HS + 0.5% β-GOS were fed a corn-based diet supplemented with β-GOS (0.1%, 0.2%, and 0.5%), respectively. Exposure to heat stress reduced feed consumption, feed efficiency and the relative weight of the liver, bursa of Fabricius, and small intestine, compared with the TNZ group. Morphometric evaluation of the small intestine revealed reduced villus surface area, villus height to crypt depth ratio (VH : CD) and intraepithelial lymphocytes (IELs) in all segments, and reduced acidic goblet cells (AGCs) in the ileum of the HSCT group compared with the TNZ group. Compared with the HSCT group, dietary β-GOS (0.2% and 0.5%) improved the feed efficiency and relative weight of the small intestine. Furthermore, dietary β-GOS (0.1%) increased villus surface area in the duodenum and IEL count in the small intestine compared with the HSCT group. Dietary β-GOS 0.5% increased villi surface area (VSA) in the jejunum and ileum, whereas the IEL count in the small intestine and acidic goblet cells (AGCs) in the jejunum and ileum were reduced compared with the HSCT group. In conclusion, dietary supplementation of β-GOS (0.2% and 0.5%) improved the growth performance and intestinal microarchitecture of broilers during heat exposure, along with partial immune stimulation. Keywords : Feed efficiency, goblet cell, intraepithelial lymphocytes, mucosal architecture, prebiotics, poultry, villus morphometry

Highlights

Intensive selection of broilers for growth rate and feed efficiency imposes high demands on their metabolic processes (Decuypere et al, 2000), but increases their sensitivity to thermal stress (Burkholder et al, 2008)
Heat exposure lowered (P
*TNZ: control group; HSCT: heat stress control group; HS + 0.1% β-GOS (0.1% β-GOS-supplemented heat-stressed group); HS + 0.2% β-GOS (0.2% β-GOS-supplemented HS group) and HS + 0.5%β-GOS (0.5% β-GOS-supplemented heat-stressed group) Values represent means of five replicates a,b,c,dMeans within a row lacking a common superscript differ significantly at (P

Summary

Introduction

Intensive selection of broilers for growth rate and feed efficiency imposes high demands on their metabolic processes (Decuypere et al, 2000), but increases their sensitivity to thermal stress (Burkholder et al, 2008). Apparent adaptations during heat stress include reduced feed intake and mobility, with a concomitant increase in drinking water and panting, as reviewed by Lara & Rostagno (2013). These behavioural modifications are coupled with redirection of blood flow to the periphery. The resulting hypoxia in the gut damages the villus enterocytes (Song et al, 2014) and goblet cells (Olsen et al, 2005), and induces the recruitment of intra epithelial lymphocytes (IELs) (Quinteiro-Filho et al, 2010) These perturbations of the mucosal barrier are not limited to the microarchitecture, but involve its microbial

Objectives

Methods

Results

Conclusion