Outhen P, Preston T R and Leng R A 2011: Effect of supplementation with urea or calcium nitrate and cassava leaf meal or fresh cassava leaf in an in vitro incubation using a basal substrate of sugar cane stalk. Livestock Research for Rural Development. Volume 23, Article #23. Retrieved , from http://www.lrrd.org/lrrd23/2/outh23023.htm