Regulation of nitrogen salvage in non-ruminants

非反刍动物氮回收的调控

• 批准号: RGPIN-2017-05275
• 负责人: Columbus, Daniel
• 金额: $ 3.79万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743520
• 关键词: Regulation; nitrogen; salvage; non; ruminants

Pigs and other non-ruminant animals are capable of salvaging nitrogen through the process of urea recycling and subsequent microbial amino acid production in the gastrointestinal tract. However, the regulatory mechanisms for urea recycling into the gut and the factors (e.g., dietary, physiological) influencing the extent of urea recycling and subsequent nitrogen utilization are not well understood. In the ruminant, it has been shown that urea transport into the rumen is due, in part, to facilitative urea transporters (UT-B and aquaporins) in addition to non-specific paracellular movement. Dietary factors, such as fibre and protein intake, may influence nitrogen salvage through altering the gut environment and changes in nutrient supply to the animal and resident microbes. The hypothesis is that urea recycling and nitrogen salvage is a regulated process that can be manipulated through changes in dietary protein and fibre intake. The objectives are to determine (i) the effect of diet composition (e.g., protein and fibre content) on extent of urea recycling and fate of recycled urea, (ii) the mechanism and regulation of urea transport across the gut wall, (iii) effect of diet composition on nitrogen utilization in the non-ruminant, and (iv) the effect of oscillating dietary protein on nitrogen utilization and retention. To address these objectives, a PhD student, 4 MSc students, and a BSc Honours thesis student will be recruited to complete a series of animal experiments in pigs, an agricultural important animal species. A combination of isotope infusion, growth performance, nitrogen-balance, and in vitro (e.g., Ussing chamber) techniques will be used. The proposed research program will provide novel information on the mechanisms regulating urea recycling and nitrogen salvage in the non-ruminant animal which will lead to the development of novel feeding programs to improve nitrogen retention and sustainability of pork production. The objectives of this research program will benefit my long-term research objective to characterize the interaction of feed components and animal physiology in order to better understand the impact of these factors on nutrient utilization for animal growth and health.

猪和其他非反刍动物能够通过尿素再循环过程和随后在胃肠道中的微生物氨基酸生产来回收氮。 然而，尿素再循环进入肠道的调节机制和因素（例如，饮食的、生理的）影响尿素再循环和随后的氮利用的程度还没有很好地理解。 在反刍动物中，已经表明，除了非特异性细胞旁运动之外，尿素转运到瘤胃中部分是由于促进尿素转运蛋白（UT-B和水通道蛋白）。 膳食因素，如纤维和蛋白质摄入量，可能会影响氮补救通过改变肠道环境和营养供应的变化，以动物和居民微生物。假设尿素再循环和氮回收是一个受调节的过程，可以通过改变膳食蛋白质和纤维摄入量来操纵。 目的是确定（i）饮食组成（例如，蛋白质和纤维含量）对尿素再循环程度和再循环尿素的命运的影响，（ii）尿素跨肠壁运输的机制和调节，（iii）非反刍动物中饮食组成对氮利用的影响，以及（iv）振荡饮食蛋白质对氮利用和保留的影响。 为了实现这些目标，将招募一名博士生，4名硕士生和一名荣誉学士学位论文学生，以完成一系列猪的动物实验，猪是农业重要的动物物种。 同位素输注、生长性能、氮平衡和体外（例如，将使用Ussing室）技术。 拟议的研究计划将提供有关非反刍动物尿素再循环和氮回收调节机制的新信息，这将导致开发新的饲养计划，以提高猪肉生产的氮保留和可持续性。 这项研究计划的目标将有利于我的长期研究目标，以表征饲料成分和动物生理学的相互作用，以更好地了解这些因素对动物生长和健康的营养利用的影响。