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

几千年来，动物产品一直被人类消费，以满足维持、生长和活动所需的蛋白质和能量需求，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单位蛋白质或能量输出的温室气体(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排放本身复杂得多；例如，奶牛等反刍动物能够利用人类无法消化的材料，有效地将无法消化的生物质转化为供人类消费的高质量营养物质，同时减少人与动物之间对资源的竞争。副产品饲料是将这样的生物质纳入牛的口粮的一种方式，虽然乳制品营养学家研究了这些饲料以降低饲料成本，但相对较少的人考虑将它们用于提高可持续性和减少动物蛋白生产的足迹。这是我建议的研究计划的重点。具体地说，这项研究将量化副产品饲料在减少食品和燃料生产过程中浪费的效果，通过使用副产品饲料减少奶牛排放来减少牛奶生产的环境影响，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.