1Charls N, Dobbins J R. Mastitis losses[J]. J Am Vet Med Assoc,1997 (170) : 1129-1132.
2Riekefink RGbtO,Barkema HW,Veenstra Set al. Prevalence of contagious mastitispathogen sinbulk tank milk in Prince Edward Is-land[J] .Can Vet J, 2006, 47 ( 6 ) : 567-572.