Determining the incidence, prevalence, and severity of ruminal acidosis in feedlot cattle

确定饲养场牛瘤胃酸中毒的发生率、患病率和严重程度

• 批准号: 436437-2012
• 负责人: Penner, Gregory
• 金额: $ 4.07万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=533515
• 关键词: Determining; incidence; prevalence; severity; ruminal

Growing and finishing beef cattle in North America are typicallyfed high grain diets (> 90 % grain, DM basis) to achieve maximum productivityin a cost-effective manner. A limitation to feeding grain-based diets is the perceived increase in the prevalence of digestive disorders, particularlysub-acute ruminal acidosis. Sub-acute acidosis is characterized bybouts of low pH in the rumen caused bythe accumulation of acids. Acidosis negativelyaffects feed (fiber) digestion, nutrient absorption from the rumen, and is an animal welfare concern. The incidence of ruminal acidosis has been measured in dairycattle using ruminocentesis as a method to collect data from numerous cows (>500) across manyherds. However, there are challenges with ruminocentesis including: high labour requirement; risk for peritonitis; and that it onlyresults in a single-data point in time for each animal to determine predicted risk. More recently, studies have evaluated the prevalenceand severityfor ruminal acidosis using indwelling pH meters. These systems provide comprehensive data regarding ruminal pH patterns over an extended duration. This data can then be used to characterize the prevalence, incidence, and severityfor ruminal acidosis based on, for example, days on feed and timing of feeding using group-fed cattle. While it is expected that feedlot cattle mayexperience ruminal acidosis, there are currentlyno known studies that document the incidence, prevalence, or severityin feedlot cattle throughout the finishing period. This research will determine critical risk periods for ruminal acidosis throughout the finishing period and will determine the incidence, prevalence, and severityfor ruminal acidosis. This will include the use of both small-pen and commercial-scale feeding operations. Furthermore, we will evaluate whether cattle experiencing more severe ruminal acidosis have altered ruminal absorptive and barrier functions.As such, the proposed research will provide the fundamental knowledge needed to quantifythe impact of ruminal acidosis on feedlot cattle as well as identifying critical risk periods so that strategies can be developed to minimize the risk, prevalence, and severityof ruminal acidosis in feedlots.

在北美，生长和肥育肉牛通常饲喂高谷物日粮（> 90%谷物，DM基础），以实现最大的生产力，在一个具有成本效益的方式。以谷物为基础的饮食的限制是消化系统疾病的患病率增加，特别是亚急性瘤胃酸中毒。亚急性酸中毒的特征是由酸积累引起的瘤胃内pH值降低。酸中毒对饲料（纤维）消化、瘤胃营养吸收有负面影响，是动物福利问题。使用瘤胃穿刺术作为一种方法，从许多牛群的许多奶牛（>500头）中收集数据，测量了奶牛瘤胃酸中毒的发生率。 然而，反刍穿刺术存在挑战，包括：劳动力需求高;腹膜炎风险;并且它仅导致每只动物的单一数据时间点以确定预测风险。 最近，研究使用留置pH计评估了瘤胃酸中毒的患病率和严重程度。 这些系统提供了有关瘤胃pH值模式在一个较长的持续时间的综合数据。 这些数据可用于描述瘤胃酸中毒的患病率、发生率和严重程度，例如，基于饲喂天数和群饲牛的饲喂时间。 虽然预期饲养场牛可能会发生瘤胃酸中毒，但目前尚无已知研究记录饲养场牛在整个育成期的发病率、患病率或严重程度。 本研究将确定整个肥育期瘤胃酸中毒的关键风险期，并确定瘤胃酸中毒的发生率、患病率和严重程度。 这将包括使用小型围栏和商业规模的喂养作业。 此外，我们将评估是否牛经历更严重的瘤胃酸中毒改变了瘤胃吸收和屏障功能，因此，拟议的研究将提供所需的基础知识，以量化瘤胃酸中毒对饲养场牛的影响，以及确定关键的风险期，以便制定战略，以尽量减少风险，患病率和严重程度的瘤胃酸中毒在饲养场。