3EANI I J.Prevntson and treament of ketosis in cows[J].Vet Bulletin,1992,62 (1):1-14.
4DANN H M,VARGA G A,PUTNAM D E.ImProving energy supply to late gestation and early postpartum dairye cows[J].DairySci,1999,82:1765-1778.
5GREENFIELD R B,CECAVA M J,JOHNSON T R,et al.Impact of dietary protein amount and rumen undegradability on intake,peripartum liver triglyceride,plasma metabolites,and milk production in transition dairy cattle[J].Dairy Sci,2000,83:703-710.
6INGVARTSEN K L,ANDERSEN J B.SYMPOSIUM:day matter intake of lactating dairy cattle integration of metabolism and intake regulation:a review focusing on periparturient animals[J].Dairy Sci,2000,83:1573-1597.