A novel approach to determining true amino acid availability and requirements based on sulphur amino acid metabolism

猪肉业是加拿大农业经济的主要贡献者，估计每年的农场收入约为35亿加元。加拿大肉类加工业年销售额近150亿美元，其中约40%是猪肉。显然，一个成功的猪肉产业对加拿大整体经济至关重要。此外，加拿大50%的猪肉出口到全球90多个国家，因此我们的行业必须保持经济竞争力，生产高质量的产品并保持环境的可持续性。本项目的目标是开发一种创新的和简单的方法来确定真正的含硫氨基酸的需求和生物利用度。我们的方法是基于对含硫氨基酸代谢的广泛接受的理解，即由饮食提供的含硫氨基酸和超过生长所需量的吸收将以硫酸盐或相关化合物的形式在尿液中排泄。本课题的最后，将提供一种新的测定含硫氨基酸真需要量和生物利用度的方法，以及一种可能用于以尿硫酸盐为指标测定其他氨基酸真需要量和生物利用度的方法。这种方法背后的概念在人类和大鼠中已经很好地建立起来，成功的可能性非常大。确定真正氨基酸生物利用度的改进方法有可能使加拿大受益，为制定最佳饲养计划提供了一个改进的平台;这反过来又将有助于猪肉行业通过最佳膳食氨基酸含量以尽可能低的成本获得最高质量的猪肉。避免氨基酸的过度配制也将通过减少氮排泄而有助于环境的可持续性，氮排泄是饮食配制不当的常见结果。这项建议将支持培训两名研究生和动物营养方面的暑期学生，这一领域一直缺乏训练有素的人员

The pork industry is a major contributor to the Canadian agriculture economy, with an estimated farm gate income of about $3.5 billion per year. The Canadian meat processing industry has annual sales of almost $15 billion, about 40% of which is pork. Clearly, a successful pork industry is important to the overall Canadian economy. In addition, 50% of Canada's pork is exported to more than 90 nations worldwide, so it is essential that our industry remains financially competitive, produces a high quality product and maintains environment sustainability. The objective of this project is to develop an innovative and simple method for the determination of true sulphur amino acid requirements and bioavailability. Our approach is based on the broadly accepted understanding of sulphur amino acid metabolism, namely that sulphur amino acids supplied by the diet and absorbed in amounts that exceed the requirement for growth will be excreted in the urine as fre sulphate or related compounds. At the end of this project, we will provide a new approach for the determination of true sulphur amino acid requirement and bioavailability, and a method that probably could be used to determine the true amino acid requirements and availability of other amino acids by using urinary sulphate as an indicator. The concepts behind this proposed method are well established in humans and rats, s the likelihood of success is very good. Improved methods for the determination of true amino acid bioavailability has the potential to benefit Canada by providing an improved platform for the formulation of optimum feeding programs; this, in turn, will assist the pork industry in achieving the highest quality pork at the lowest possible cost, through optimum dietary amino acid content. Avoiding over formulation of amino acids will also contribute to environmental sustainability by reducing nitrogen excretion, a common outcome when diets are improperly formulated. This proposal will support the training of two graduate students plus summer students in animal nutrition, a field that continually experiences an inadequate supply of trained personnel