Beauchemin K A,Farr B I,Rode L M.Effects of alfalfa silage chop length and supplementary long hay on chewing and milk production of dairy cows[J].J.Dairy Sci.,1994,77(5):1 326～1 339.
[4]
Heinrichs J.Evaluating forages and TMRs using the penn state particle size separator[R].Penn State Cooperative Extension Service,1996.DAS 96～20.
[5]
Grant R J,Colenbrander V F,Mertens D R.Milk fat depression in dairy cows:Role of particle size of alfalfa hay[J].J.Dairy Sci.,1990,73(7):1 823～1 833.
[6]
Lammers B,Heinrichs J,Buckmaster D.Method helps in determination of forage,TMR particle size requirements for cattle[J].Feedstuffs,1996,68(41):14～20.
[7]
Rippel C M,Jordan E R,Stokes S R.Evaluation of particle size distribution and ration uniformity in total mixed rations fed in Northcentral Texas[J].Prof.Anim.Sci.,1998,14(1):44～50.
[8]
Woodford S T and Murphy M R.Effect of forage physical form on chewing activity,dry matter intake,and rumen function of dairy cows in early lactation[J].J.Dairy Sci.,1988,71(3):674～684.
