【作者】 胡建春；

【导师】 陆承平；

【作者基本信息】 南京农业大学 ， 兽医学， 2004， 硕士

【摘要】 乳腺炎是影响奶牛业发展最严重的疾病。为研究不同的环境条件与奶牛乳腺炎发生率的关系，2002年1月至2003年10月，对苏北盐城地区一大型奶牛场(A牛场)连续进行22个月的隐性乳腺炎的SMT(上海隐性乳腺炎检测法)检测，同时选择不同饲养环境条件的B、C、D、E、F、G、H等7个奶牛场进行对比检测。实验期间，共检测泌乳奶牛2550头次9666个乳区，检出阳性乳牛1425头，隐性乳腺炎个体发生率为55.9％；检出阳性乳区2677个，乳区发生率27.7％。 A牛场22个月内共检测奶牛2140头，检出阳性乳牛1209头，个体发生率56.5％，检测乳区8081个，阳性乳区2152个，乳区发生率26.6％。分春、夏、秋、冬四个季节进行统计学分析，个体发生率与季节没有明显的关系。 对检测的9666个乳区进行分析，发现左、右乳区隐性乳腺炎的发生率几乎一致，而前后乳区的区别与隐性乳腺炎的发生率有明显关系，主要表现为后乳区隐性乳腺炎的发生率明显高于前乳区。 对饲养数量不同的6个牛场的220头奶牛、挤奶方式不同的3个牛场的271头奶牛、饲料营养状况不同的2个牛场的221头奶牛进行隐性乳腺炎的检测，同时进行统计学分析，结果显示：季节、饲养数量、挤奶方式、饲料营养状况的差异与隐性乳腺炎的发生率没有明显的关系。 对同一牛场不同地面条件的208头奶牛、在上一个泌乳期是否曾发生隐性乳腺炎的64头奶牛、对环境不同消毒次数的193头奶牛、发病是否采取隔离措施的306头奶牛、是否按规定程序挤奶的3个牛场的210头奶牛进行隐性乳腺炎的检测，同时进行统计学分析，结果显示：地面条件、是否曾发生隐性乳腺炎、环境的消毒次数、发病是否隔离、是否按规定程序挤奶等条件的差异，隐性乳腺炎的发生率存在明显差异。 为了解盐城地区引发奶牛乳腺炎的主要病原菌，以便采取合理的治疗与防治措施，2003年9月在该地区4个奶牛场采集16份奶样(其中患临床型乳腺炎的7份，隐性乳腺炎的9份)进行细菌学分离与鉴定。首先在兔血琼脂平皿培养基和麦康凯培养基上培养，观察菌落形态、溶血性，再挑选单个菌落接种于THB琼脂平皿培养基，进行纯化培养，将纯化培养菌接种于肉汤，进行涂片、染色、镜检，作好记录，保存菌种。结果有3份奶样未分离出细菌，另外13份奶样共分离到16株细菌，其中有3份奶样各分离出2株细菌。根据细菌的培养特征、染色形态特征、排列等进行初步归类，应用葡萄球菌属、肠杆菌科、链球菌三种生化微量鉴定管进行鉴定。结果鉴定出葡萄球菌5株，肠杆菌5株，链球菌4株，酵母菌2株。分别占检出细菌总数的31.3％、不同饲养环境下奶牛乳腺炎的发生率与综合防治31.器、25%、12.5%.细菌分离鉴定的结果表明，本地引发奶牛乳腺炎的致病菌与其它地区报道的大致相同.更多还原

【Abstract】 Mastitis was the most serious disease to dairy farming. In order to find out the relationshipbetween the mastitis occurrence rates and the different farm conditions, the SMT analysis tothe subclinical mastitis were carried out in a big dairy farm (A farm) at Yanchen area, northof Jiangsu during Jan of 2002 to Oct of 2003 .The contrast tests were also done hi differentfarm conditions of B, C, D, E, F, G, H farms. In this experiment, 2250 dairy cows and9666 udder regions were determined. The result showed: positive were 1425, the cattlepositive incidence was 55.9%; positive udder regions were 2677,the udder region positiveincidence was 27.7%.In A farm,2140 cattle were determined during 22 months, and positive catties were 1209,_the cattle positive incidence was 56.5%; positive udder regions were 2152,the udder regionpositive incidence was 26.6%. The statistic analysis were done according as differentseasons, and the result showed that the cattle positive incidence was no obvious relationwith seasons.The analysis results to 9666 udder regions showed that the mastitis occurrence rates werealmost same in left and right udder regions. And the mastitis occurrence rates between frontand back udder regions had obvious relation with the subclinical mastitis occurrence rates,the subclinical mastitis occurrence rates were obvious high in back udder regions.The subclinical mastitis analysis and statistic analysis were carried out in 220 catties of 6different feeding scale farms, 271 catties of 3 different milking method farms and 221catties of 2 different feeding nutrition farms. The results showed that the incidence rate ofsubclinical mastitis had no relation with different seasons, feeding scale, milking method,nutrition.Statistic analysis were done in 208 catties of 1 different feeding condition farm, 64 cattiesof different original diseases, 193 catties of different times of disinfection, 306 catties ofdifferent isolation of sick dairy cow and 210 catties of 3 different milking with rationalprogram farms. The results showed that the occurrence rate of the subclinic mastitis wasobviously connected with different feeding condition, original diseases, times ofdisinfection, isolation of sick dairy cow, milking with rational program.In order to find out the main mastitis pathogens in Yanchen and to take rational preventionand cure methods, the pathogens isolated and identified in milk from 16 dairy cow in 4dairy farms (including 7 clinical mastitis milk and 9 subclinical mastitis milk) were done in Sep of 2903. The shape and hemolysis of bacterium clones were observed after cultivating on rabbit blood agar culture medium and MacConkey medium. Single bacterium clone was picked out and inoculated in THE agar medium, after culturing, single clone was selected to inoculate in broth at 37 "C for 24 hours. Isolates were identified using conventional methods: Gram-stained cell morphology, colony morphology , micro-biochemical test and then stored at -20 *C . 16 strains were isolated from 13 milk samples (including various 2 strains in 3 individual milk samples ), no bacteria were isolated in 3 milk samples. The isolated strains contained 5 Staphylococcus aureus , 5 E. coll, 4 Streptococcus and 2 Yeast fungu, and this indicated that the pathogens in this area were almost same with other area’s reports.更多还原