1 The John M. Airy Symposium: Visions for Animal Agriculture and the Environment January 2006 Kansas City, Missouri Using a nutrition model to implement the NRCS Feed Management Standard to reduce the environmental impact of a concentrated cattle feeding operation D. G. Fox 1 , T. P. Tylutki 2 , L. O. Tedeschi 3 and P.E. Cerosaletti 4 1 Cornell University, Dept. of Animal Science, 2 Agriculture Modeling and Training Systems LLC, 3 Texas A&M University, Dept. of Animal Science, and 4 Cornell University Cooperative Extension of Delaware Co. Abstract Environmental hurdles to sustainable livestock production Livestock farms are under increasing pressure to reduce manure nutrient excretions and nutrient accumulation on agricultural land in order to meet environmental regulations. To date, nutrient management regulations in New York (NY) and other states in the US have addressed the Clean Water Act through implementation of the National Resource Conservation Service (NRCS) 590 standard for nutrient management on farms with concentrated animal feeding operations (CAFO). The NRCS 590 standard focuses on reducing risk to water quality as the result of over-application of fertilizer and manure, and prevention of direct manure losses to our streams and lakes; this is accomplished through the use of the phosphorus (P) runoff index, the nitrate leaching index, and land grant university crop nutrient guidelines. Unfortunately, current nutrient management planning efforts do little to reduce importation and subsequent loading of nutrients onto farms and watersheds. Recently, the USDA-NRCS has identified the need to reduce manure nutrients through improved feed management on farms with animal feeding operations, and have developed a national standard (NRCS 592) to be used as part of the nutrient management planning process (NRCS USDA, 2003). The purpose of a feed management plan as described in the national NRCS 592 standard is: 1) to supply the quantity of available nutrients required by livestock while reducing the quantity of nutrients excreted, and 2) improve net farm income by feeding nutrients more efficiently. Livestock feeding and management systems and environmental issues vary from state to state. In some states, the predominant livestock enterprises are commercial swine or poultry operations; in others it is commercial beef and/or dairy operations. In some regions, cattle are kept primarily in dirt lots; in others, they are completely confined to barns. Feed source ranges from all home grown with adequate land to re-cycle the nutrients to all purchased with the manure being spread on land in crop farms in the area. Environmental priorities range from protecting public drinking water sources to emission control. Therefore each state NRCS modifies the national 592 standard to address the specific issues in their state. The NY NRCS 592 Standard (NY NRCS USDA, 2005) was developed through