Effect of xylanase and xylo-oligosaccharide supplementation on growth performance and faecal bacterial community composition in growing pigs

Abstract This study was conducted to investigate the effects of xylanase (XYL) and xylo-oligosaccharide (XOS) supplementation on the growth performance and faecal bacterial community composition in growing pigs over time. In this 35-day trial, a total of 464 grower pigs with an average initial body weight (BW) of 14.5 kg (SD ±1.56 kg) were blocked into mixed sexed pens of 4 to 5 pigs balanced for BW, sex and litter origin. Pens were randomly allocated to 1 of 4 dietary treatments in a 2 × 2 factorial treatment arrangement with 2 concentrations of supplementary XYL (0 and 0.15 g/kg) and XOS (0 and 0.20 g/kg). On a weekly basis, pen feed intake and pigs were weighed to calculate pig performance. Faecal samples from 32 male pigs were collected on days 1, 14 and 35 of the trial and analysed to profile the bacterial communities through 16S ribosomal ribonucleic acid (rRNA) sequencing of the V4 region on the MiSeq platform (Illumina). There was no effect of XYL on pig performance, nor was there an interaction between XYL and XOS. Pigs supplemented with XOS had a poorer gain to feed ratio during the first week (Day 1 to 7) of the trial (P