1. Dep. of Dairy and Anim.Sci. The Pennsylvania State Univ. University Park PA 16802
2. USDA‐ARS, Pasture Systems and Watershed Mgt. Res. Unit, U.S. Regional Pasture Res. Lab. University Park PA 16802
3. Dep. of Dairy and Anim. Sci. The Pennsylvania State Univ. University Park PA 16802