From left: James Ringler, Glenn Stoltzfus, Agriculture Secretary Tom Vilsack, Duane Stoltzfus and Dwight Stoltzfus. The Stoltzfus brothers explain how the compost solids are produced from their anaerobic digester. An anaerobic digester is a component of a waste management system that captures biogas for energy production a byproduct of this system are compost solids that are used for bedding for the dairy’s cattle. The anaerobic digester practice is part of a planned conservation management system that manages manure and/or comprehensive nutrient management system. Secretary Vilsack visited the Stoltzfus’ Pennwood Dairy Farms in Berlin, PA on Tuesday, July 17, 2012 to announce the U.S. Department of Agriculture’s (USDA) energy efficiency programs and announced a new effort to help rural consumers make affordable, energy-efficient improvements to their homes and businesses. USDA photo by Bob Nichols.