8Barrett P C, Miler G Y, A ndezson C R, et al. Milk production and somatic cell count in milking dairy herds [J]. Dairy Sci, 1990, 73:27816- 28000.
9Barkema H W, Van Der Ploeg J D , Schukken Y H, et al. Management style and its association with bulk milk somatic cell count and incidence rate of clinical mastitis[J]. J dairy Sci, 1999, 82:1655-1663
10Eberhart R J, Hutchinson L J and Spencer S B. Relationships of bulk tank somatic cell count to prevalence of intramammary infection and to indices of herd production[J]. J. Food Prot, 1982, 45:1125-1128
