1. Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL.
2. Corresponding author, Phone: 217-333-9510. Fax: 217-244-0323. E-mail: vsingh@ uiuc.edu
3. Department of Animal Science, University of Missouri, Columbia, MO.
4. Crop Conversion Science and Engineering Research Unit, Eastern Regional Research Center, ARS, USDA, Wyndmoor, PA.