1. West Central Research and Outreach Center, University of Minnesota, Morris 56267
2. Haskell Agricultural Laboratory, University of Nebraska, Concord 68728
3. Department of Animal Sciences, The Ohio State University, Columbus 43210
4. Department of Agricultural and Biosystems Engineering, South Dakota State University, Brookings 57007
5. Department of Animal Sciences, University of Missouri, Columbia 65211
6. Department of Animal and Range Sciences, South Dakota State University, Brookings 57007