Screening of lactic acid bacteria and prebiotics for synbiotics and their effects on piglets

Prebiotics(inulin,fructo-oligosaccharide(FOS),xylo-oligosaccharide(XOS)and isomalt-oligosaccharide(IMO))and lactic acid bacteria(LAB)(S1,L7,L17 and L18)were selected for the screening of synbiotics.Their effects on diarrhea rate and growth performance of piglets were confirmed.Results showed that,both inulin and FOS stimulated the growth of four strains of LAB.S1 and L18 could utilize XOS,but only S1 could use IMO.With FOS+inulin(m∶m=2∶8)as substrate,mixed culture of LAB(Lm)was able to produce largest amount of lactate((23.49±0.67)mmol·L-1)after 24 h of fermentation.Both S1 and Lm inhibited the growth of K88 and mixed culture of four Escherichia coli strains(Km).Compared to LAB(S1 or Lm)and prebiotics(FOS+XOS or FOS+inulin),synbiotics especially Lm combined with FOS+inulin or FOS+XOS(m∶m=1∶1)could significantly decrease diarrhea rate both before and after weaning.Only Lm+(FOS+inulin)was observed to significantly improve daily weight gain before weaning.After weaning,daily weight gain increased and feed/gain ratio decreased in all treatment groups.This effect was greater in synbiotics groups than in LAB groups and prebiotics groups.The results suggest that combination of mixed LAB with FOS+inulin or FOS+XOS may be effective in feeds for weaning piglets.