7Van Soest P J,Robertson J B,Lewis B A.Methods for dietary fiber,neutral detergent fiber,and nonstarch Polysaccharides in relation to animal nutrition[J].Journal of Dairy Science,1991,(74):3583-3597.
8Falkner L K,Casler M D.Preference for smooth bromegrass clones is affected by divergent selection for nutritive value[J].Crop Science,1998,38:690-695.
