3AFRC,Energy and Protein Requirements of Ruminants[M].1993,An advisory manual prepared by the AFRC Technical Commitree on Responses to Nutrients.Compiled by G.Alderman,in collaboration with B.R.cottrill.
4Canas R;R.Quiroz,C.Leon-Velarde;A Posada (2002) Estimation of the Metabolizable Energy for Grazing.Production svstems and natural Resouree Management Department[A].Working Paper # 5 September 2002.International Potato Center(CIP).
