Folate and regulation of immune and anti-oxidant defense mechanisms in the laying hen

2006年，加拿大家禽和蛋类产业占加拿大农业总收入的7.0%，相当于26亿加元。在过去的五十年里，家禽业在营养、遗传学、工程和管理等多个领域取得了巨大进步，从而最大限度地提高了生产效率，包括生长和产蛋。营养素的供应有明确的目标：1）满足蛋鸡的维持和生产需求; 2）确保足够的营养储备，以有效应对压力（环境，微生物，病毒，毒理学等）。和3）相对于消费者偏好优化或增强蛋的营养概况。一般来说，该行业侧重于实现第一个目标，因为这是生产者传统经济回报的基础。因此，对于某些关键营养素，公布的值可能会低估那些需要满足额外的目标，确保最佳的母鸡健康或提高鸡蛋营养浓度。水溶性维生素叶酸反映了这样一种营养素，目前的需求可能被低估。在以前的研究中，申请人提供了强有力的证据，证明鸡蛋叶酸含量可以通过超过产蛋母鸡需求估计的叶酸摄入量而富集2-3倍，并且鸡蛋中发现的天然叶酸是高度可用的。此外，这项研究提供的证据表明，叶酸补充剂高于目前在工业中使用的叶酸补充剂，可以显著减少含硫氨基酸同型半胱氨酸，这是一种有记录的可能引起细胞损伤的代谢物。目前的建议将推进我们的初步观察，通过调查机制，调节叶酸的吸收和代谢的蛋鸡，和叶酸的状态对母鸡健康指数的影响，在面对免疫挑战。该研究计划将通过推进与特种鸡蛋市场未来发展有关的知识，并通过确定新的方法来提高鸟类健康，对鸡蛋行业产生直接影响。

In 2006, the poultry and egg industries in Canada accounted for 7.0% of total Canadian agricultural receipts, an amount equivalent to $2.6 Billion. During the past five decades, the poultry industry has made great steps in several areas including nutrition, genetics, engineering, and management, thereby maximizing the efficiency of performance, including growth and egg production. Nutrients are supplied with distinct goals in mind: 1) meeting the maintenance and production needs of the laying hen; 2) ensuring adequate nutritional reserves to mount an effective response to a stressor (environmental, microbial, viral, toxicological, etc...) ; and 3) optimizing or enhancing the nutritional profile of the egg relative to consumer preferences. In general, the industry has focused on achieving the first goal, as this has formed the basis of the traditional economic returns to the producer. Therefore, for certain key nutrients, the published values may underestimate those needed to meet the additional goals of ensuring optimal hen health or enhanced egg nutrient concentrations. The water soluble vitamin folate reflects one such nutrient where current requirements are likely underestimated. In previous research, the applicants have provided strong evidence that egg folate contents can be enriched by 2-3 fold with folic acid intakes in excess of laying hen requirement estimates, and that the natural folate found in the egg is highly available. Furthermore, this research has provided evidence that folic acid supplementation above that currently employed in the industry yields significant reductions in the sulphur amino acid homocysteine, a metabolite with documented potential to invoke cellular damage. The current proposal will advance our initial observations by investigating the mechanisms regulating folate uptake and metabolism in the laying hen, and the impact of folate status on indices of hen health in the face of an immune challenge. The research program will have direct implications for the egg industry by advancing knowledge pertaining to the future development of the specialty egg market, and through the identification of novel methods to enhance bird health.