Amino Acid Nutrition and Metabolism in Chickens
Amino Acid Nutrition and Metabolism in Chickens
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DOI：
10.1007/978-3-030-54462-1_7
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发表时间：
2021-01-01
期刊：
影响因子：
--
通讯作者：
Wu, Guoyao
中科院分区：
文献类型：
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作者：
He, Wenliang;Li, Peng;Wu, Guoyao
禽肉和蛋类为人类消费提供高质量的动物蛋白[含有足够数量和适当比例的氨基酸（AAs）]，因此，对所有个体的生长，发育和健康起着重要作用。由于人们越来越关注家禽生产的次优效率及其对环境可持续性的影响，因此人们非常关注通过添加低成本的晶体AA或动物蛋白饲料的替代来源来配制低蛋白饮食和精确营养。这需要更好地了解AA的营养和代谢鸡。虽然历史上的营养研究主要集中在体内不能合成或合成不足的营养必需氨基酸（EAA）上，但越来越多的证据表明，传统分类的营养非必需氨基酸（NEAA），如谷氨酰胺和谷氨酸，在鸡的生长和产蛋中具有蛋白质合成以外的生理和调节作用。此外，与其他鸟类物种一样，鸡不能充分合成相对于其营养和生理需求的甘氨酸或脯氨酸（体内最丰富的AA，但以低含量存在于植物源饲料中）。因此，这两种AA在家禽日粮中必须足够。动物蛋白（包括反刍动物肉骨粉和水解羽毛粉）是鸡营养中甘氨酸和脯氨酸的丰富来源。显然，鸡（包括肉鸡和产蛋鸡）对所有蛋白原性AA都有饮食需求，以实现其最大生产力并保持最佳健康，特别是在不利条件下，如热应激和疾病。这是家禽营养的一个范式转变，从70年前的“理想蛋白质”概念，只关注EAA，到关注功能性AA，包括EAA和NEAA。
Both poultry meat and eggs provide high-quality animal protein [containing sufficient amounts and proper ratios of amino acids (AAs)] for human consumption and, therefore, play an important role in the growth, development, and health of all individuals. Because there are growing concerns about the suboptimal efficiencies of poultry production and its impact on environmental sustainability, much attention has been paid to the formulation of low-protein diets and precision nutrition through the addition of low-cost crystalline AAs or alternative sources of animal-protein feedstuffs. This necessitates a better understanding of AA nutrition and metabolism in chickens. Although historic nutrition research has focused on nutritionally essential amino acids (EAAs) that are not synthesized or are inadequately synthesized in the body, increasing evidence shows that the traditionally classified nutritionally nonessential amino acids (NEAAs), such as glutamine and glutamate, have physiological and regulatory roles other than protein synthesis in chicken growth and egg production. In addition, like other avian species, chickens do not synthesize adequately glycine or proline (the most abundant AAs in the body but present in plant-source feedstuffs at low content) relative to their nutritional and physiological needs. Therefore, these two AAs must be sufficient in poultry diets. Animal proteins (including ruminant meat & bone meal and hydrolyzed feather meal) are abundant sources of both glycine and proline in chicken nutrition. Clearly, chickens (including broilers and laying hens) have dietary requirements for all proteinogenic AAs to achieve their maximum productivity and maintain optimum health particularly under adverse conditions such as heat stress and disease. This is a paradigm shift in poultry nutrition from the 70-year-old "ideal protein" concept that concerned only about EAAs to the focus of functional AAs that include both EAAs and NEAAs.