Effects of feeding finisher pigs with chicory or lupine feed for one or two weeks prior to slaughter with respect to levels of Bifidobacteria and Campylobacter

Summary

Prebiotics are non-digestible oligosaccharides acting by stimulating the growth of bacteria being beneficial for the gastrointestinal health of the host and may serve as a means to prevent pathogens. This study aimed to assess if inclusion of chicory or lupines (prebiotics) in the diet of pre-slaughter pigs for just 1 or 2 weeks could change the composition of their intestinal microbiota, stimulate the growth of bifidobacteria and help to lower the level of the important foodborne pathogen Campylobacter spp.
A total of 48 pigs of initial 90 kg live weight were fed with either a lupine (organic concentrate with 25% blue lupine seed), chicory (organic concentrate with 10% dried chicory roots) or control (100% organic concentrate) diet for 1 week (24 pigs) or 2 weeks (24 pigs) before slaughter. The campylobacter level in rectal faecal samples after 0, 1 and 2 weeks of feeding and in the luminal content from ileum, caecum and colon at slaughter was determined by direct plating. DNA extracted from the luminal content of distal ileum and caecum, was used for terminal restriction fragment length polymorphism (T-RFLP) analysis of the composition of intestinal microbiota and for measuring the amount of Bifidobacterium spp. and total bacterial DNA by quantitative real-time PCR (qPCR). Campylobacter spp. were excreted by all pigs and present in the luminal content from distal ileum to midway colon with particular high numbers in caecum, but the excretion was reduced by 10-fold in pigs fed lupines for 1 week as compared to control and chicory fed pigs (mean Log10 2.9 vs. 4.1 CFU/g) (P<0.05). The qPCR analysis showed that feeding with lupines for 1 week resulted in higher levels of bifidobacteria in caecum as compared to the other diets (P<0.05), whereas the level of bifidobacteria in distal ileum was generally higher and independent of feed treatment (P>0.05). T-RFLP analysis showed that four of the most abundant bacteria with terminal restriction fragments (T-RFs) values >5% relative intensity of total abundance differed between the feed treatments (P<0.05). Then, this study showed that even a short-term alternative feeding strategy with prebiotics in the diet of pre-slaughter pigs elicited changes in the composition of the intestinal microbiota, where lupine increased the level of bifidobacteria in caceum and reduced the campylobacter excretion level after 1 week.