1. F. A. Atuo (atuo@wisc.edu), C. Wyatt, B. Determan and T. J. O'Connell, Dept of Natural Resource Ecol
2. P. Saud, Dept of Extension Animal Sciences and Natural Resources, New Mexico State Univ., Las Cruces
3. J. A. Crose, Dept of Plant and Soil Sciences, Oklahoma State Univ., Stillwater, OK, USA.