Mohsen K, Sirjani M K, Tahmasbi A M, Khoram Abadi E I and Torbaghan A E 2017: Effects of sodium and calcium bentonite on growth performance and rumen ammonia in Holstein bulls. Livestock Research for Rural Development. Volume 29, Article #144. Retrieved , from http://www.lrrd.org/lrrd29/8/phd29144.html