Effects Of Mannan-Oligosaccharide On The Gastro-Intestinal Bacteria Of Weaning Piglets

Weaning is a transition period for piglets that is from breast-fed to solid diet. It may cause retarded growth and high diarrhea rate due to the change in microbial population in the intestinal tract at the stressful time. The aim of study was conducted to evaluate the effects of mannan-oligosaCcharide on the growth performance, diarrhea rate and fermentation characteristics of weaning piglets in vitro and in vivo, while bacterial community and Lactobacillus composition were also investigated.1 Effect of mannan-oligosaccharide and sugar beet pulp on intestinal microbial fermentation in vitroIleal and colon digesta were collected as sources of inocula from piglets of 25d old on day 1 of weaning. 48 hour fermentation of mannan-oligosaccharide (MOS) and sugar beet pulp (SBP) as substrates were investigated in vitro to determine the effects on gastrointestinal microbiota. Gas production and volatile fatty acids (VFAs) and pH were analysed. The results showed that the production of gas and VFA linearlyly increased with the increasing concentration of MOS and SBP in culture medium. For ileum inocula, all MOS treatments resulted in acetic acid Proportion significantly lower than the control, while propionic and butyric acids proportions significantly higher than the control. In SBP treatments, acetic acid was still the major acid, but its value decreased while butyric acid increased as the substrate concentration increased. For colon inocula, all MOS and SBP treatments showed higher butyric acid proportion than the control; the proportion of acetic acid linearly decreased as MOS and SBP concentration increased. Meanwhile, high level of MOS and SBP treatment resulted in a lower pH after fermentation compared with that before fermentation and the control, pH values were lower for SBP treatment than MOS treatment at the same addition level. Furthermore, pH linearly decreased with the increasing concentration of MOS and SBP. The results suggested that MOS and SBP could promote piglet gastro-intestinal microbial fermentation, especially the production of butyric acid, and decrease pH, implying their potential as prebiotics.2 Effects of mannan-oligosaccharide on gastro-intestinal bacterial community and Lactobacillus of weaning piglets in vitro fermentationEffects of mannan-oligosaccharide (MOS) and sugar beet pulp (SBP) on gastro-intestinal bacterial community and Lactobacillus of weaning pigs were investigated. The results showed that the similarity of bacterial community of ileal and colon digesta increased to 85～97% after fermentation by M0S and SBP treatment from the 20% before fermentation. DGGE analysis revealed MOS treatment increased the bacterial diversity and band number (P<0.05) by ileal and colon fermentation. SBP treatment increased band number and bacterial diversity (P<0.05) in colon, but the diversity was not affected from ileal fermentation. By using Lactobacillus group-specific primers, the similarity of Lactobacillus between ileal and colon from the DGGE profile was 94%. The LactobaciUus diversity index was similar from ileal and colon digesta (0.83～0.94 vs 0.82～0.93) before and after fermentation. The band number was in the range of 7 to 9 for both ileal and colon before and after fermentation. The results suggest that the similarity of bacterial community from ileal and colon slightly increased, but Lactobacillus was not affected by MOS and SBP treatment. Clone and sequenceanalysis showed that species related to Prevotella and Ruminococcus were the dominant bacteria in the gut of weaning pigs. MOS and SBP may cause a shift of species in Prevotella and as well as Ruminococcus. Results also showed that Lactobacillus sobrius and Lactobacillus amylorous were the dominant Lactobacillus members in the gut of weaning piglets. But MOS and SBP had no effect on the Lactobacillus.3 Effects of mannan-oligosaccharide on the growth of Lactobacilus pure cultureThe effects of mannan-oiigosaccharide (MOS) on the growth of Lactobacillus in vitro fermentation were investigated by three swine pure culture Lactobacillus strains (strain S, L and M) already isolated by our laboratory. The results revealed that OD values of three Lactobacillus strain for the MOS treatment were higher than the control group without MOS supplementation, but the growth curves were different among the strains. A lower pH was observed for MOS treatment of the three strains than that for the control group. The changes in pH were not stable between the time points. Lactic acid concentration was higher for MOS treatment of the three stains than that for the control group. It suggested that MOS could be used by Lactobacillus strains to produce lactic acid and reduce pH in vitro. 4 Effects of mannan-oligosaccharide on the growth of LactobaciUus and swine pathogen E.coli (F4) during co-cultureEffects of mannan-oligosaccharide (MOS) as substrate on the growth of Lactobacillus and swine pathogen E.coli (F4) was investigated by co-culture technique. The results showed that MOS were utilized by both Lactobacillus and swine pathogen E.coli (F4). But Lactobacillus grew faster than the pathogen strain during culture. A significant increase in lactic acid concentration (P<0.05) and a significant decrease in pH (P<0.05) were observed from co-culture with MOS treatment compared with that from the co-culture without MOS or pathogen E.coli (F4) pure culture. Moreover, the changes in numbers of Lactobacillus and E.coli, lactic acid concentration and the reduction of pH were observed during the first 12h fermentation. The results suggested that Lactobacillus was selectively used by MOS to grow and produce lactic acid and reduce pH which may effectively inhibit pathogen E.coli (F4) growth.5 Effects of mannan-oligosaccharide on the growth performance and fecal VFAs in weaning pigletsA total of 34 weaning piglets from six litters were randomly assigned into two groups and offered basal diet (control) and basal diet plus mannan-oligosaccharide (MOS) for 4 weeks to evaluate the effects of MOS on growth and feed efficiency after weaning. Fecal VFAs concentrations were observed on day 7 and 28. Results showed that during the 1^st week, there were no observed effects of MOS on ADG, feed/gain (F: G), the diarrhea rate and VFAs concentration. But from the 2nd week onwards, MOS supplemented diet significantly increased ADG, F: G and reduced the diarrhea rate (P<0.05). At the 4th week, VFAs concentrations were higher for MOS treatment compared with that for the control group(P>0.05). It indicates that MOS seems to improve the growth performance and reduce diarrhea rate of weaning piglets after one week adaptation for MOS.6 Effect of mannan-oligosaccharide on bacterial community and Lactobacillus from piglet feces after weaningA total of 34 weaning piglets from six litters were randomly assigned into two groups and offered basal diet (control) and basal diet plus manno-oligosaccharide (MOS), respectively. Faecal samples were collected on day 1 (before first feeding), 7, 14, 21 and 28 after weaning. PCR/DGGE was used to investigate the diversity of the bacterial communities and Lactobacillus of weaning piglets. Results showed that piglets from the same litter had a higher similarity (81%～88%) of the bacterial community on day 1 (before weaning) compared with that after weaning (61%～70%) from the DGGE profile. The similarity of microbial community for MOS treatment gradually increased to 70% from the reduction during the first week, but the value in the control remained around 61%. Diversity analysis showed on day 28 the diversity index of the bacterial community from the MOS treatment was 1.52 and the control group was 1.38. The difference in the diversity index between the two groups increased from 0.09 on day 1 to 1.14 on day 28. DGGE band enumeration revealed that band number of for piglets supplemented with MOS was larger than that for the control. Analysis of Lactobacillus DGGE profiles revealed that on day 14 the diversity index of Lactobacillus community for MOS treatment decreased to the lowest which is 0.71, and then went back to 0.75 on day 28, while the values for the control group decreased to 0.61 on day 21 and then back to 0.74 on day 28. The Lactobacillus diversity index for MOS treatment was higher than that for the basal diet during the whole period. Meanwhile, MOS treatment resulted in the reduction of band numbers which is 9 on day 7, while the values for the control group decreased to 7 on day 14. At the other time point, band numbers from MOS treatment were higher than that from the basal diet. The results demonstrated that weaning had caused rapid changes of the bacterial community and Lactobacillus of piglets and that MOS supplemented in the diet could result in a rapid development and consequently early establishment of a high diverse bacterial community and Lactobacillus after weaning.