Prebiotics in weaner and grower pigs

Alongside increased pressure to reduce antimicrobial usage, the UK pig industry is facing an imminent ban on therapeutic levels of Zinc oxide. Hence, seeking suitable feeding concepts that promote health and prevent disease is of utmost importance for the industry’s sustainability and profitability. Prebiotics positively influence gut bacterial community composition, thus improve host health and the nutritive value of feedstuffs. New-generation prebiotics like xylo-oligosaccharides (XOS) are gaining attention for monogastric nutrition. The research in this thesis aimed to determine the effect of XOS, with or without alternative additives, on weaner and grower pig growth, bacteria modulation and fibre digestibility. In addition, faecal L-lactate concentration and inert markers for fibre digestibility analysis were investigated. Results showed XOS had limited effects on pig performance but altered ileal bacterial community composition of weaner pigs, including beneficial Lactobacillus stimulation. XOS increased ileal fermentative activity and non-starch polysaccharide (NSP) digestibility, indicating a stimulatory effect on increasing the bacteria’s fibre-degrading capacity. The effects of XOS were lost when combined with long-chain inulin, demonstrating incompatibility of the products. XOS and fructans increased the faecal digestibility of cellulose and NSPs. Furthermore, L-lactate was detected in piglet faeces at low levels, faecal bacteria metabolism of L-lactate was rapid, and a handheld device was found to be a suitable real-time method for L-lactate analysis. Due to ileal fractionation, titanium dioxide (TiO2) was shown to be an unsuitable inert marker for NSP digestibility whilst cellulose showed realistic initial results, yet further validation is required. TiO2 fractionation was rectified at the faecal level, whilst post-ileal degradation rendered cellulose infeasible as a marker for total tract NSP digestibility. In conclusion, XOS affected bacterial community composition and increased NSP digestibility but did not translate into improved growth, with a relatively short feeding period being the likely explanation. Further work is required to expand on these findings.