2006 Annual Report 4d.Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and West Texas A&M University, Canyon, Texas. Additional details of the research can be found in the report for the parent CRIS 6209-31630-002-00D, Minimizing the Environmental Impact of Livestock Manures Using Integrated Management Regimens. Nonpregnant yearling heifers for Experiment 1 (growing study) were procured and were allowed 4 weeks to acclimate to the facility, after which 259 animals were selected for the study. Corn and sorghum distiller's grains were stored in airtight ensiling bags measuring 10 feet in diameter to prevent mold formation. As a consequence of rising forage prices during the current drought, the study was ended after 61 days. Fresh feces and air-dried pen manure samples were collected from the pens and blood samples (via jugular venipuncture) and individual cattle weights were obtained. For the initial phase of Experiment 2 (finishing study) two hundred nonpregnant yearling heifers were processed on arrival, and were adapted to a finishing diet. The first block of heifers was harvested after 74 days on feed. Fresh feces and air-dried pen manure samples were obtained at harvest. Two hundred cattle from Experiment 1 were enrolled in the second phase of Experiment 2. Cattle will be fed until they have an estimated backfat thickness of 0.5 inches.