Comparison Of The Ability Of Degrading Fiber By Fecal Microbiota Between Meishan And Landrace Sows

Dietary fiber palys an extremely important role in sow practical application. As an important enegy source for sows, fiber can also impove the reproductive performance of sows and host welfare. Thus, it is important to study intestinal fiber-degrading microflora and the relationship between fiber-degrading microflora and host for theoretical and practical significance.The dietary fiber is mainly degraded by microbiata in the intestinal tract of pigs. At present, studies on fiber-degrading bacteria have been focused by many researchers in the intestinal nutrition field. However, information on comparison of fiber-degrading ability of gut bacteria between different genetical pigs is still limited. The aim of this thesis is to compare fiber-degrading bacteria in the feces, and their ability of degrading different fibers between Meishan and Landrace sows.1Comparison of fiber degrading microbiota in faeces between Meishan and Landrace sowsThe aim of this section was to compare fiber-degrading baceria microbiota in faeces between the Meishan and Landrace sows. Fecal samples of Meishan and Landrace sows were collected, and used for analysis of microbiota composition. DGGE anlysis of total bacterial community showed that no significant difference in faeses of Meishan and Landrace sows. Similarity analysis of DGGE profiles revealed that the faecal samples of Meishan and Landrace sows showed no significant difference. Results of Real-time PCR showed that as compared to Landrace sows, the16S rRNA gene copies of total baceria in feces of Meishan sows was significantly higer (P<0.05), while there was no significant difference in the16S rRNA gene copies of Bacteroides, Clostridium Leptum group, Fibrobacter succinogenes, Ruminococcus flavefaciens, Ruminococcus albus as well as their percentages relative to total bacteria (P>0.05).2In vitro fermentation characteristics of eight different fiber substrates by fecal microbiota of Meishan and Landrace sows In vitro fermentation characteristics of eight different fiber substrates was investigated by uing feces from pure-breed Meishan and Landrce sows as sources of inocula. Eeight different substrates included:pectin, cellulose, xylan, inilin, wheat hul, wheat bran, maize pulp and Alfalfa. After96hours fermentation, gas production was recorded, samples were collected and used for the determination of the concentration of volatile fatty acids (VFAs). Results showed that the cumulative gas production, the concentration of acetate and total VFAs were significantly higer (P<0.05) when feces from Landrace sows was used as inocula as compared with Meishan sows. There was no significant difference in the concentration of propionate and butyrate between these two breeds (P>0.05). T1/2and Tmax was significantly lower (P<0.05) in Landrace sows than Meishan sows. The order of the degradability of these eight substrates was:inulin> wheat bran> pectin> alfafa> wheat hull> maize pulp> xylan> cellulose. The results suggest that Landrace may have a stronger ability of degrading fiber.3Comparison of the ability of degading four different fiber substrates between Meishan and Landrace sows in vitro and their fiber degrading microbiota during fermentationThe aim of this section was to compare fiber-degrading capability and baceria microbiota difference between Meishan and Landrace sows. Fecal were collected as sources of inocula from pure-breed Meishan and Landrce.72hour fermentation of Pectin、 Inilin、Wheat bran and Alfalfa.These four different substrates were investigated in vitro to determine the effects on Gas production and volatile fatty acids (VFAs).24、48、72h Fermentation fluid samples of Meishan and Landrace sows were collected, and used for analysis of microbiota composition. DGGE results showed that Meishan and Landrace sows share the same bacteria band when different substrates were fermented while also have substrates-special and breed special band. The mincrobial population is increased sharply from Oh to48h since the fermentation, and then decresed since48h to72h. when pectin as substrate, The final gas production、OMCV、16S rRNA gene copies of Bacteroides are significantly higher in Meishan sows than Landrace sows but the acetate and total VFA concentration did not show significant difference. The final gas production、 OMCV、acetate concentration、total VFA concentration、16S rRNA gene copies of Ruminococcus flavefacien and Ruminococcus albu are significantly higer (P<0.05) in Landrace sows than Meishan sows during inulin fermentation,while no significantly difference during wheat bran and alfalfa fermentation. Landrace sows show stronger ability to degrade inulin than Meishan sows, but there is no significant difference in degrading pectin, wheat bran and alfafa.