1. Agronomy Dep. Univ. of Florida Gainesville FL 32611‐0500 USA
2. Range Cattle Research and Education Center Univ. of Florida 3401 Experiment Station Ona FL 33865 USA
3. Animal and Vet. Sciences Dep. Clemson Univ. Blackville SC 29817 USA
4. North Florida Research and Education Center Univ. of Florida Marianna FL 32446 USA