9Webster A J F, R.J.Dewhurst, C.J.Waters. Ahemative Approaches to the Characterization of Fcedstuffs for Ruminants in Recent Ad- vances in Animal Nutrition, 1988:167.
6NRC.Nutrient Requirements of beef cattle(M). . 1984
7Moore J E,Kunkle W E.Evaluation of equations for estimating voluntary intake of forages and forage-based diets. Animal Science . 1999
8Mertens D R.Predicting intake and digestibility using mathematical models of ruminal function. Journal of Animal Sciences . 1987
9Johne Moore,Daniel J,Undersander.Relative Forage Quality:An Aiternative to Relative Feed Value and Quality Index. Proceddings 13~(th) Annual Florida Nutrition Symposium . 2002
10Oba M,Allen M S.Evaluation of the importance of the digestibility of neutral detergent fiber from forage : effects on dry matter intake and milk yield of dairy cows. Journal of Dairy Science . 1999