1Dahlquist S P, B. P. Chew. Effects of vitamin A and B-carotene on mastitis in dairy cows during the early dry period [J]. J. Dairy Sci., 1985,68 (suppl.1):191 .
2Oldham E R, R. J. Eberhart, L. D. Muller. Effects of supplemental vitamin A and Bcarotene during the dry period and early lactation on udder health [J]. J. Dairy Sci.,1991,74:3 775-3 781.
3LeBlanc S J, T. H. Herdt, W. M. Seymour, et al. Peripartum serum vitamin E, retinol, and beta-carotene in dairy cattle and their associations with disease [J]. J. Dairy Sci.,2004,87:609-619.
4Weiss W P, J. S. Hogan, D. A. Todhunter, et al. Effect of vitamin E supplementation in diets with a low concentration of selenium on mammary gland health of dairy cows[J]. J. Dairy Sci.,1997,80:1 728- 1 737.
5Erskine R J, R. J. Eberhart, P. J. Grasso, et al. Induction of Escherichia coli mastitis in cows fed selenium-deficient or eleniumsupplemented diets [J]. Amer J Vet Res.,1989,50:2 093.
6Erskine R J, R. J. Eberhart, R. W. Scholz. Experimentally induced Staphylococcus aureus mastitis in selenium-deficient and seleniumsupplemented dairy cows[J]. J. Amer.Vet.Med.Assoc.,1990,51:1 107- 1 111.
7Scaletti R W, D. S, Trammell, B. A. Smith, et al. Role of dietary copper in altering response to intramammary E. coli challenge, in Proc. Int. Mastitis Symp., Natl. Mastltis Counc./Am. Assoc. Bovine Practitioners, Vancouver, BC, Canada,2001:29-33.
8Tomlinson D J, M. T. Socha, C. J. Rapp, et al. Summary of twelve trials evaluating the effect of feeding eomplexed zinc methionine on lactation performance of dairy cattle[J]. J. Dairy Sci.,2002,85(suppl.1): 106.
9Whitaker D A, H. F. Eayres, K. Aitchison, et al. No effect of a dietary zinc proteinate on clinical mastitis, infection rate, recovery rate, and somatic cell count in dairy cows [J]. Vet. J.,1997,153:197- 204.
10Santos M V, F. R. Lima, P. H. M. Rodrigues, et al. daFonseca. Plasma ascorbate concentrations are not correlated with milk somatic cell count and metabolic profile in lactating and dry cows [J]. J. Dairy Sci.,2001,84:134-139.