Effect of TASCO, a seaweed extract on rumen functions of ruminants: microbial diversity and activities in sheep

提高畜牧业的产量和健康水平对提高加拿大畜牧业的可持续性至关重要。瘤胃是一个宽敞的胃前厌氧发酵室，维持着丰富的微生物群落，迅速定植和消化饲料颗粒。瘤胃及其复杂的微生物群落在以挥发性脂肪酸和微生物蛋白的形式为宿主的代谢功能提供能量方面发挥着重要作用。因此，改善瘤胃功能对显著提高反刍动物的生产效率可能起到至关重要的作用。此外，最近在艾伯塔省一家饲养场肉牛加工厂爆发的O157：H7大肠杆菌揭示了这种病原菌在动物下巴中的定植，以及处理受污染动物的下巴部分可能是污染该工厂的过程之一。因此，减少这种致病菌在牛的胃肠道中的定植可以显著降低这种细菌在植物中的污染发生率。 Tasco®-AOS是一种天然产品，含有天然提取的多糖和低聚糖的混合物，由加拿大新斯科舍省的阿卡迪亚海洋植物有限公司从海藻中提取。尽管Tasco®-AOS已被证明具有改善动物胃肠道健康的生物活性功能，但其对反刍动物微生物生态的影响尚未得到很好的表征。最近的研究表明，Tasco®-AOS可以影响分离的瘤胃细菌的活性，以及不同饲料的体外瘤胃消化，并可能减少大肠杆菌O157：H7在反刍动物中的脱落。这些表明，Tasco®-AOS可能会影响瘤胃功能，并可能通过排除大肠杆菌O157：H7等病原体而改变微生物种群。因此，本项目旨在研究1)Tasco®-AOS能否改善瘤胃微生物活性和瘤胃上皮功能；2)该产品是否能减少O157：H7大肠杆菌在羔羊GIT中的定植。

Improvement of animal's production and health is vital to enhance the sustainability of Canadian livestock industry. The rumen is a capacious pre-gastric anaerobic fermentation chamber sustaining a rich community of microorganisms that rapidly colonize and digest feed particles. The rumen and its complex microbial community play a major role in providing energy in the form of volatile fatty acids and microbial protein for the metabolic function of the host. Therefore, improve the rumen function may play an essential role to significantly enhance the production efficiency of ruminants. In addition, recent outbreak of E. coli O157:H7 in a feedlot beef cattle processing plant in Alberta reveals the colonization of this pathogenic bacteria in GIT of animals and handling of the GIT parts of contaminated animals may be one of the courses to contaminate the plant. Therefore, reducing the colonization of this pathogenic bacterium in the GIT of cattle can significantly reduce the incidence of the contamination of this bacterium in the plant. Tasco®- AOS, is a natural product containing a mixture of naturally derived polysaccrides and oligosaccharides extracted from seaweed Ascophyllum nodosum by Acadian Seaplants Ltd., a Nova Scotia based Canadian company. Although Tasco®- AOS has been shown to have bioactive functions which improve the health of an animal's GI tract, its effects on the microbial ecology in ruminants has not been well characterized. Recent studies have revealed Tasco®- AOS can affect the activities of isolated rumen bacteria, as well as the in vitro ruminal digestion of different feeds and may reduce the shedding of E. coli O157:H7 in ruminants. These suggest that Tasco®- AOS may impact rumen function and potentially alter microbial populations through the exclusion of pathogens such as E. coli O157:H7. Therefore, the proposed project aims to investigate 1) whether Tasco®- AOS can improve ruminal microbial activity and rumen epithelial function, and 2) if this product can reduce the E. coli O157:H7 colonization of GIT of lambs.