7Menke K H,Steingass H. Estimation of the energetic feed value obtained from chemical analysis and in vitro gas production using rumen fluid [ J]. Animal Research and Development, 1988,28 ( 7 ) :47-55.
8Menke K H, Raab L, Salewski A, et al. The estimation of the digestibility and metabolizable energy content of rumi- nant feeding stuffs from the gas production when they are incubated with rumen liquor in vitro [ J ]. Journal of Agri- cultural Science, Cambridge, 1979,93 ( 1 ) :217-222.
9青海省草原总站.青海省草地资源统计册[M].西宁青海人民出版社,1982:5-10.
10NRC. Nutrient requirements of sheep [M ]. Washington D C : National Academy Press, 1985.
