【作者】 李永安；

【导师】 毕丁仁；

【作者基本信息】 华中农业大学 ， 预防兽医学， 2005， 硕士

【摘要】 奶牛乳房炎是奶牛的常见病和多发病之一,因其病因复杂,难以防制,给奶牛饲养业带来了巨大的经济损失。本试验对湖北省宜昌市几个奶牛养殖小区的隐性乳房炎发病情况及发病规律进行了调查,并对奶牛乳房炎的病原菌进行了分离、鉴定及药物敏感性测定等一系列试验,结合当地的饲养管理条件制定了奶牛乳房炎的综合性防制措施,取得了较好的结果。 在2003年4月到2004年3月为期一年的时间里,每季度到牛场抽检1次,每次随机抽检“健康”奶牛60头,计240个乳区,4次共计240头960个乳区。经上海乳房炎检验法(SMT)检验:发现该地区隐性乳房炎的发病率为31.25%,乳区发病率为22.19%;奶牛隐性乳房炎的发生率随季度变化而变化,以第二季度发病率为最高,不同季节奶牛隐性乳房炎的发病率差异显著(P<0.05);不同乳区隐性乳房炎的发病率差异显著(P<0.05),左侧乳区发病率明显高于右侧乳区(6.88%);不同胎次间的隐性乳房炎的发生率有所差异,以3胎、5胎隐性乳房炎的发病率最高,而头胎牛的发病率较低,但不同胎次之间隐性乳房炎发病率差异不显著(P>0.05)。 在对20份临床型乳房炎乳样和25份经SMT检验呈强阳性的隐性乳房炎乳样的病原菌的分离鉴定中,有32份乳样有菌生长,临床型乳房炎病原茵的检出率为80%(16/20),隐性乳房炎检出率为64%(16/25);共分离到51株细菌,其中来源于临床型乳样的有32株,来源于隐性乳房炎的有19株,隐性乳房炎一般都为单一病原感染,占81.25%(13/16);而临床型乳房炎多为混合感染,占62.5%(10/16)。经培养特性、染色镜检、生化鉴定及动物实验,结果金黄色葡萄球菌29株,占56.86%,表皮葡萄球菌15株,占29.41%;无乳链球菌2株,占3.92%;大肠杆菌3株,占5.82%;铜绿假单胞菌2株,占3.92%。在所选用的17种常用药物中,新霉素、乙酰螺旋霉素、壮观霉素、强力霉素对所分离的病原菌都有较好的杀灭作用,庆大霉素、红霉素、氯霉素、卡那霉素对革兰氏阳性菌的杀菌效果较好,而对革兰氏阴性菌不敏感。常用药物如青霉素、链霉素、磺胺类药物的抑菌效果不明显,大多已产生耐药性。更多还原

【Abstract】 Dairy mastitis happens frequently in cattle farm. Because of the complex cause and no effective therapy, it has brought the cattle farms large economic loss. To find an effective and feasible scientific method to control and cure the bovine mastitis broke out in many cattle farms in Yichang city, Hubei province, especially the subclinical bovine mastitis. A series of experiments were designed to discover the reason why the disease happen and in what circumstance mastitis easily be inflected. And combined with the local cattle farm administrant system, a systemic prevention and cure management rule is draft and work well.During the time between April 2003 to March 2004, 240 samples around the breast were gotten from 60 cattle with no clinical symptom in every quarter, 960 samples in all. All the samples were tested with the method SMT (Shanghai Mastitis Test) , the result showed that: the incidence of local subclinical bovine mastitis is 31.25%, the quarter incidence is 22.19%.The incidence of subclinical bovine mastitis fluctuates in different quarters and differentia is prominent (P < 0.05), the second quarter has the highest incidence; the quarter incidence also fluctuates in different inflected quarters and differentia is prominent (P < 0.05), the quarter incidence of the left part is 6.88% higher than the right part; the incidence changes in different fetal orders, the subclinical mastitis incidence of the 3rd and 5th is higher than the others, and the first one is the strongest one, but differentia is not prominent (P > 0.05).In the experiment for investigating the pathogenesis for bovine mastitis and analyzing its sensitivity against medicine, we collected 25 milk samples from the cattle infected by bovine subclinical mastitis and 20 milk samples from the clinically infected cattle, got 51 isolates from 32 samples, including 29 isolates of Staphylococcus aureus, 4 of Staphylococcus epidermidis, 3 of E.coli., 2 of Streptococcus agalactiae, 2 of Pseudomonas pyocyaneas. The result of sensitivity against 17 kind of common antibiotics shows that all the strains are sensitive to Neomycin Sulfate, Acetylspiramycin, Spectinomycin Doxycycline, and all gram-positive strains are sensitive to Gentamicin Sulfate, Erythromycin, Kanamycin Sulfate, Chloramphenicol, while the opposite togram-negative strains. The most popular antibiotics such as Pennicillin, Streptomycin Sulfate, sulfonamide, are not so effective because resistant against antibiotics above produced in majority of them.更多还原