When measuring the sustainability of a dairy farm, one should take into account its technical and economic performance, its stewardship of natural resources, and the norms and policies of the society in which the farm operates. This means that managing dairy herd nutrition depends not only on meeting the nutrient requirements of the animals for full expression of their genetic potential, but also on the relationships between cattle nutrition, other components of the farm, the local economy and the aims of the dairy farm. In this chapter we discuss the importance of phosphorus and nitrogen in cow nutrition, the associated environmental concerns and a range of sustainable solutions to these concerns. We also address the carbon footprint associated with dairy farming by examining a case study of intensive dairy production systems in California and Wisconsin.