宁波市奶牛乳房炎发病及综合防治试验研究

Investigation on prevalent bovine mastitis-causing bacteria in Ningbo and comprehensive control trial

为了解宁波地区奶牛乳房炎发病及主要病原菌构成,采用乳房炎诊断试剂(HMT)对宁波市8个奶牛场307头泌乳牛的1249个乳区进行了隐性乳房炎流行情况调查,采集HMT反应阳性(++)及强阳性(+++)乳区奶样进行细菌分离与鉴定;用纸片扩散法检测主要病原菌对常用抗菌药物敏感性,并选择具代表性牧场进行乳房炎综合防治试验。结果显示,宁波市奶牛隐性乳房炎的头阳性率为71.3%,乳区阳性率为33.5%。主要病原菌的检出率依次为:凝固酶阴性葡萄球菌47.1%、无乳链球菌20.4%、停乳链球菌17.3%、金黄色葡萄球菌5.1%和乳房链球菌3.9%。主要病原菌对青霉素、氨苄青霉素、庆大霉素、复方新诺明和链霉素等药物有不同程度的耐药性,对头孢类及苯唑青霉素敏感。综合防治措施的实施可以明显降低桶奶总细菌数,改善牛奶品质。

Objective：To investigate the prevalence of subclinical mastitis and drug-sensitivity of the main pathogens in dairy cows in Ningbo region. Methods： A total of 1 249 quarters from 307 lactating cattle on 8 farms were investigated for subclinical mastitis by HMT test, and bacteria were isolated from HMT positive milk. The sensitivity of bacteria to antibiotics was also measured. Based on this result, comprehensive measures were carried out on one out of the 8 farms to control subclinical mastitis. Results： 71.3 % of 307 cows with 33.5% of 1 249 quarters were detected to have subclinical mastitis. The main pathogens were coagulase negative Staphylococci （47.1%）, Streptococcus agalactiae （20.4%）, Streptococcus dysgalactiae （17.3%）, Staphylococcus aureus （5.1%） and Streptococcus uberis （3.9%）. Most of the cases were infected by one kind of bacteria. The bacteria were resistant to gentamicin, sulfamethoxazole compound and streptomycin but sensitive to penicillin and ampicillin. Conclusion： The main causes of subclinical mastitis in Ningbo region was staphylococci and streptococci. Following intergrated control trail, total bacterial counting in bulk was reduced and milk quality was also improved.