Nguyen Thi Hong Nhan, Nguyen Van Hon, Nguyen Trong Ngu, Nguyen Thi Thu Hong, Preston T R and Leng R A 2003: Effect of drenching with cooking oil on performance of local “Yellow” cattle fed rice straw and cassava foliage. Livestock Research for Rural Development. Volume 15, Article #49. Retrieved , from http://www.lrrd.org/lrrd15/7/nhan157.htm