Studies On Exogenous Oligosaccharides' Degradation, Conversion, Utilization And Passage In The Digestive Tract And Its Effects On Microflora, Immunity And Nutrient Digestibility In Sheep

Effects of exogenous oligosaccharides (Os) on immunity, microflora and nutrient digestibility and the exogenous Os'degradation,conversion,utilization and passage in the digestive tract was studied in this paper. The results in 5 parts were as follows:Part 1 Studies on the optimum level of Exogenous Os in vitro Three wethers with permanent ruminal canula were used for donor of rumen liquid to investigate the optimum level of exogenous Os in vitro. During the trail, the substrate ingredients in vitro were same as the wethers'basal diet. Soybean oligosaccharides (SBOs) were added into the ingredients. The results showed that the optimum level of SBOs was 1.2% DM. it was founded that the added SBOs could be degradated and translated into VFA.Part 2 Studies on exogenous Os'utilization and passage in digestive tract Nine wethers with permanent rumianl, proximal duodenum and termial ileum cannulas were divided into three groups to investigate the utilization and passage in digestive tract by continuous feeding and continuous infusion of SBOs. During the trail, the three groups were fed a basal diet with different SBOs added levels, 1.2%, 0.6%, 0.0%. The results showed that retained NDOs in the rumen (RNDOs) was 2.6g, the passage flow of RNDOs from the rumen was 12.3g/d, the passage flow of small intestine nondigestible oligosaccharides (SINDOs) in the duodenum and ileum were 17.9g/d and 19.1g/d respectively, the NDOs excreted with faeces was 5.6g/d. Rumen and caecum were the two main place where Os were been degradated and utilized. Infusion of high level exogenous Os raised the concentration of total VFA and propionic acid in the rumen.Part 3 Studies on the effects of NDOs on rumen microflora Nine wethers with permanent rumianl cannulas was divided into three groups to investigate the the change of counting of total bacterial, cellulose-decomposed bacteria, methanogen in the rumen by feeding a basal diet and infusing three levels of SBOs via rumianl cannula. The results showed that the total bacterial and protozoa countings were unchanged, and the cellulose-decomposed bacteria counting were raised, but the methanogen counting was decreased at the high infused level.Part 4 Studies on the effects of NDOs on immunity in sheep Nine wethers with permanent rumianl, proximal duodenum and termial ileum cannulas were divided into three groups to investigate the effects on immunity by feeding a basal diet and infusing three levels of SBOs via rumianl, proximal duodenum and termial ileum cannulas respectively. The results showed that infusion of SBOs via rumianl and proximal duodenum cannulas were raised the counting of CD4+, the value of CD4+/CD8+ and the contents of IgA, IgG in jugular vein.Part 5 The study of exogenous Os on whethers'gain and feed efficiency Nine wethers with permanent rumianl cannulas was diveided into three groups to investigate the the effects of exogenous Os on gain and feed efficiency by feeding a basal diet and infusing three levels of SBOs via rumianl cannula. The results showed that the the apparent digestibility of DM,CP,NDF and ADF was improved. With the levels of infusion of SBOs raised the daily gain increased by 37.9% & 25.7%, and decreases the rate of feed/gain by 18.8% &11.5%, respectively.