Bartlett P C, Miller G Y, Lance S E, Heider L E
Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824.
J Dairy Sci. 1992 May;75(5):1241-52. doi: 10.3168/jds.S0022-0302(92)77873-4.
Forty-eight dairy herds in Ohio were selected as a stratified random sample for participation in a disease monitoring study to relate the prevalence of IMI with coliform and environmental streptococci to herd management and environmental conditions. Management and environmental conditions were assessed by farm inspection and by an interview with the dairy producers. A separate analysis for each independent variable identified many potential disease determinants. A multivariable analysis of a covariance model to predict the prevalence of coliforms had 6 model df (R2 = .47). Increased prevalence of coliform infection was associated with an increased amount of milk remaining in the udder after milking, use of free stalls, regular use of a running water wash, increased person hours per cow spent milking, and poor sanitation. The multivariable model for environmental streptococci used 5 model df (R2 = .51). Increased prevalence of environmental streptococci was associated with poor sanitation, increased number of days dry, use of tie stalls, no use of a shared wash cloth, and no use of an individual dry cloth.
俄亥俄州的48个奶牛群被选为分层随机样本，参与一项疾病监测研究，以探究乳房内感染（IMI）与大肠菌群及环境链球菌的流行率与牛群管理和环境条件之间的关系。通过农场检查和与奶农的访谈来评估管理和环境条件。对每个自变量进行单独分析，确定了许多潜在的疾病决定因素。用于预测大肠菌群流行率的协方差模型的多变量分析有6个模型自由度（R2 = 0.47）。大肠菌群感染流行率的增加与挤奶后乳房内残留的牛奶量增加、使用自由牛栏、定期使用流水冲洗、每头牛挤奶花费的人工小时数增加以及卫生条件差有关。环境链球菌的多变量模型使用了5个模型自由度（R2 = 0.51）。环境链球菌流行率的增加与卫生条件差、干奶天数增加、使用系栏、不使用共用毛巾以及不使用个体干布有关。
