1. USDA, ARS, Roman L. Hruska U.S. Meat Animal Research Center, PO Box 166, Clay Center, NE 68933
2. Department of Animal Science, South Dakota State University, Brookings 57007
3. University of Nebraska West Central Research and Extension Center, North Platte 69101
4. Department of Agricultural Sciences, Northwest Missouri State University, Maryville 64468