1. Animal Metabolism-Agricultural Chemicals Research Unit, USDA ARS, 1605 Albrecht Blvd. Fargo, North Dakota, 58105-5674, Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, 97331, and Environmental Management and By-Product Utilization Laboratory, 10300 Baltimore Ave, BARC-West, Beltsville, Maryland, 20705-2350