Evaluating whole flaxseed and flaxseed meals as energy and protein sources for high-producing dairy cows

加拿大的亚麻籽产量约占世界亚麻籽产量的40%，其中萨斯喀彻温省占60%。加拿大生产的亚麻籽约有80%出口，其余的在当地加工。亚麻籽传统上是用溶剂萃取法提取油，副产品是亚麻籽粉。一小部分亚麻籽通过使用压榨机加工（也称为冷压）进行加工，冷压亚麻籽粉作为副产品生产。处理这些副产品的主要市场将是加拿大西部的奶牛群。通常，整个亚麻籽含有42-46%的油和21%的蛋白质，由于其高含量的能量（油）和蛋白质，使其成为奶牛的良好补充剂。亚麻籽粉比整个亚麻籽含有更高水平的蛋白质（31-33%），使其成为奶牛必需氨基酸的丰富来源。冷榨亚麻籽粉比溶剂提取的亚麻籽粉（<1%）含有更大量的残余油（7-14%），因此当将冷榨亚麻籽粉包括在饮食中时，较高的残余油将增加能量密度。亚麻籽油富含多不饱和脂肪酸（PUFA），如亚油酸和亚麻酸。这些PUFA在瘤胃生物氢化过程中产生理想的中间产物，称为共轭亚油酸（CLA）。这些CLA对人类有许多健康益处，包括减少炎症反应，改善免疫功能，预防心血管疾病和癌症。用亚麻籽或亚麻籽粉喂养的奶牛的奶制品可以富含CLA，从而使这些增值奶制品对注重健康的消费者更具吸引力。此外，亚麻籽是木酚素的丰富来源，木酚素在消化道中转化为生物活性化合物（主要是肠内酯），吸收后可以转移到牛奶中。当在牛奶中食用时，这些生物活性化合物可以降低心血管疾病的风险。拟议的研究将调查如何纳入整个亚麻籽，溶剂提取和冷压亚麻籽粉奶牛饮食影响牛奶产量，牛奶脂肪酸和肠内酯谱。

Canada produces about 40% of world flaxseed production, with Saskatchewan accounting for 60% of this production. About 80% of flaxseed that is produced in Canada is exported, with the remainder being processed locally. Flaxseed is traditionally processed using solvent extraction to extract the oil, with flaxseed meal being produced as a byproduct. A small proportion of flaxseed is processed by using expeller processing (also termed cold-pressing), with cold-pressed flaxseed meal being produced as a byproduct. The primary market for disposal of these byproducts will be dairy herds in western Canada. Typically, whole flaxseed contains 42-46% oil and 21% protein, making it a good supplement for dairy cows because of its high contents of energy (oil) and protein. Flaxseed meal contains greater levels of protein (31-33%) than whole flaxseed, making it a rich source of essential amino acids for dairy cows. Cold-pressed flaxseed meal contains greater amounts of residual oil (7-14%) than solvent-extracted flaxseed meal (<1%), so the higher residual oil would increase energy density when cold-pressed flaxseed meal is included in the diet. Flaxseed oil is high in polyunsaturated fatty acids (PUFA) such as linoleic and linolenic acids. These PUFA yield desirable intermediates during rumen biohydrogenation, known as conjugated linoleic acids (CLA). These CLA have numerous health benefits in humans, including reduced inflammatory response, improved immune function, and prevention of cardiovascular diseases and cancer. Milk products from dairy cows that are fed flaxseed or flaxseed meals can be enriched in CLA, thus making these value-added milk products more appealing to health-conscious consumers. Also, flaxseed is a rich source of lignans, which are converted to bioactive compounds (primarily enterolactone) in the digestive tract that can be transferred into milk after absorption. When consumed in milk, these bioactive compounds can reduce the risk of cardiovascular disease. The proposed research will investigate how inclusion of whole flaxseed, and solvent-extracted and cold-pressed flaxseed meals in dairy cow diets influence milk production, and milk fatty acid and enterolactone profiles.