Enhancing the sustainability of dairy farm rations through the use of byproduct feeds

数千年来，人类一直食用动物产品来满足维持、生长和活动所需的蛋白质和能量，但这种营养来源伴随着碳足迹成本。反刍动物营养学家为减少动物生产的环境足迹所做的大部分努力都集中在减少每单位蛋白质或能量产出的温室气体（GHG）排放上，并取得了巨大成功。然而，作为一个系统，粮食生产对环境的影响远比单纯的排放复杂得多;例如，奶牛等反刍动物能够利用人类消化不了的材料，有效地将难以消化的生物质转化为人类消费的高质量营养素，同时减少人类和动物之间对资源的竞争。副产品饲料是一种将这样的生物质纳入牛口粮的方法，虽然乳制品营养学家已经研究了这些饲料作为降低饲料成本的方法，但相对较少的人认为它们可以提高可持续性并减少动物蛋白生产的足迹。具体而言，本研究将量化副产品饲料在减少食品和燃料生产过程中的浪费方面的效果，通过使用副产品饲料减少奶牛排放来减少牛奶生产对环境的影响，并利用副产品饲料改善动物健康和生产力。

Animal products have been consumed by humans for millennia to meet protein and energy requirements for maintenance, growth, and activity, but this source of nutrients comes with a carbon footprint cost. Much of the effort made by ruminant nutritionists to reduce the environmental footprint of animal production has been focused on reducing greenhouse gas (GHG) emissions per unit of protein or energy output, with great success. Nevertheless, the environmental effects of food production as a system are far more complex than emissions alone; for example, ruminants such as dairy cattle are able to utilize materials that are unavailable for human digestion, effectively converting undigestible biomass into high-quality nutrients for human consumption while decreasing competition between humans and animals for resources. Byproduct feeds are a way to incorporate biomass like this into cattle rations, and while dairy nutritionists have studied these feeds as ways to reduce feed costs, relatively few have considered them to improve sustainability and decrease the footprint of animal protein production. This is the focus of my proposed research program.Specifically, this research will quantify the effect of byproduct feeds in reducing waste in food and fuel production processes, reduce the environmental impact of milk production by using byproduct feeds to reduce emissions from dairy cattle, and utilize byproduct feeds to improve animal health and productivity.