Biological basis for variation in feed intake and nutrient utilization

我们代谢研究项目的总体目标是为加拿大的牛肉和乳制品生产系统做出重大贡献，以满足消费者对可持续和对社会负责的动物农业行业日益增长的需求。有足够的证据表明，动物和人类相对于维持和增重需求以及营养物质运输和代谢效率的采食量变化具有遗传基础。这些采食量、维持和增重需求的差异，根据体型和生长情况，低于或高于预期值，现在作为剩余采食量报告。然而，这些反应的生理和代谢基础尚不清楚。我们利用ISc技术获得的甲烷产量、营养吸收和Km差异的初步数据表明，这些差异是由胃肠道（GIT）水平上可测量的生理和代谢过程支撑的。本实验室的长期目标是阐明饲喂相似日粮的动物采食量和养分利用效率变化的生理机制。特别是，将研究一组特定的胃肠运动指数（收缩的频率、幅度和持续时间）和特定活性（钠+/葡萄糖共转运蛋白，SGLTs 1、2和3）营养转运蛋白在调节动物对胃肠道营养供应改变的不同反应中的作用。此外，还将研究胃肠道中涉及关键营养物质葡萄糖和谷氨酰胺代谢的代谢过程及其与不同营养/饮食诱导反应的关系。详细了解胃肠道中的这些生理和代谢过程以及运动和营养转运体所起的作用，将为未来改进饲料/食物评估铺平道路，不仅考虑瘤胃和瘤胃后消化，还考虑胃肠道中营养物质的命运

The overall goal of our metabolic research program is to make significant contributions to the beef and dairy production systems in Canada that addresses the increasing consumer demands for a sustainable and socially responsible animal agricultural industry.There is enough evidence to indicate a genetic basis for the variation in feed intake relative to maintenance and gain requirements and the efficiency of nutrient transport and metabolism in animals and humans. These differences in feed intake, maintenance and gain requirements measured as below or above the expected value on the basis of size and growth are now reported as residual feed intake. However, the physiological and metabolic bases for these responses remain unclear. Our preliminary data of differences in methane production, nutrient absorption and Km using ISc technology lead to believe that these differences are underpinned by measurable physiological and metabolic processes at the level of the gastrointestinal track (GIT).The long term goal of this laboratory is to elucidate the physiological mechanisms regulating the variation in feed intake and efficiency of nutrient utilization between animals fed similar diets.  In particular, the roles of a specific group of gastrointestinal motility indices (frequency, amplitude and duration) of contractions and specific active (Sodium+/glucose co-transporter, SGLTs 1, 2 and 3) nutrient transporters in mediating differential animal responses to altered nutrient supply to the GIT will be studied. In addition, the metabolic processes involved in the metabolism of key nutrients, glucose and glutamine and their relationships to differential nutrient/dietary induced responses in the GIT will be studied. A detailed understanding of these physiological and metabolic processes in the GIT and the roles played by motility and nutrient transporters should pave the way for future improvements in feed/food evaluations that considers not only ruminal and post-ruminal digestion but the fates of nutrients in the GIT