8Duffield T F,Kelton D F,et al. Use of test day milk fat and milk protein to detect subclinical ketosis in dairy cattle in Ontario. Can Vet J,1997,38(11) :713-718.
9Escobsa. Effect of varying dietary ratio of sodium and chloride on the response of lactating dairy cows in hot weathcr[J]. J Dairy Sci, 1982,65 : 552- 565.
10Hwang S Y, M J Lee, et al. Monitoring nutritional status of dairy cow in Taiwan using milk protein and milk urea nitrogen[J]. Asian-Aus J Anim Sei,2000,13(12) :1667-1673.