两种抗生素对长途运输肉牛的抗应激和促生长作用及对比研究

为了探讨延胡索酸泰妙菌素、泰乐菌素对经长途运输后肉牛的抗应激和促生长作用及效果,试验将经长途运输后的27头肉牛随机分为试验1组、试验2组和对照组,每组9头,试验1组和试验2组肉牛运后10 d内每天分别灌服延胡索酸泰妙菌素和肌肉注射泰乐菌素,对照组不做任何处理。结果表明:试验1组肉牛发病率比对照组低8.89%,且平均每头牛体重增长量比对照组多7.150 kg;试验2组肉牛发病率比对照组低15.01%,且平均每头牛体重增长量比对照组多8.710 kg。说明延胡索酸泰妙菌素、泰乐菌素对经长途运输后肉牛的抗应激和促生长均有一定作用,且后者的作用效果优于前者。     

2种抗应激处理对“肉牛运输应激综合征”的疗效对比研究

本试验旨在探讨肉牛启运前进行抗应激处理对降低肉牛引入后发病的效果,在运输前,对第1批的69头牛进行以肌肉注射科特壮为主的综合用药处理,对第2批的39头牛进行肌肉注射牛支原体灭活疫苗的处理,运输时间分别为32 h和36 h,途中不提供水和任何食物,牛运达后继续观察30 d,记录环境温湿度及发病情况,结果显示几乎肉牛始终都处于热应激的状态中;第1批牛和第2批牛在运达后陆续发病,2批牛分别在运后第9天和第13天前时,试验组均比对照组的累积发病数低,但之后到运后1个月,试验组又均比对照组的累积发病数高;运后第1批牛要比第2批牛的发病率和死亡率分别高1.23%和20.29%。     

抗应激处理对肉牛引入后发病的影响

[目的]旨在探讨肉牛启运前进行抗应激处理对降低肉牛引入后发病的效果。[方法]对两批共99头牛分别进行启运前注射牛支原体灭活疫苗（第一批）与盐酸氯丙嗪（第二批）,途中运输时间分别为36 h与48 h,运输途中不给食物与饮水。牛运抵后继续观察35 d,记录发病情况。[结果]两批对照牛的平均发病率为67%。小体重组（250－300 kg）牛的发病率显著高于大体重组（300－350 kg组和350－400 kg组）发病率（P〈0.05）。虽然接种疫苗诱导产生了抗体,但接种应激加重了牛引入后发病。牛运输前肌注盐酸氯丙嗪组较对照组发病率显著降低（P〈0.05）,且0.6 mg/kg比0.3 mg/kg效果更好（P〈0.05）。[结论]启运前采用肌注盐酸氯丙嗪的抗应激处理能显著降低牛引入后的发病率。     

中草药对肉牛运输应激的防治研究

长途运输肉牛容易产生应激反应,为了解中草药对肉牛运输后应激性症状是否存在改善作用,试验选取24头临床检查健康、体重相近(约300 kg)、8月龄左右的西门塔尔杂交牛,随机分为4个组(试验组Ⅰ、试验组Ⅱ、试验组Ⅲ和对照组),每组6头,试验组Ⅰ灌服参苓白术散,试验组Ⅱ灌服刺五加液,试验组Ⅲ灌服自拟方剂(黄芪多糖+参苓白术散加减)。结果表明,运输应激会导致机体严重失重,运达时4组失重率由大到小顺序为:对照组、试验组Ⅱ、试验组Ⅰ和试验组Ⅲ,运达后30 d基本都恢复到运前体重。运达后对照组的体温、呼吸和心率都显著升高(P0.05),有的指标呈现极显著升高(P0.01);试验组Ⅲ的体温、呼吸和心率相对最为稳定,其次为试验I,然后为试验组Ⅱ,运达后1 d基本都恢复到运前水平。说明自拟方剂可使肉牛运输前后的体重、体温、呼吸和心率指标变化相对缓和,有一定的抗应激作用,参苓白术散和刺五加液也有一定的抗应激作用,但不及自拟方剂效果好。     

黄芪多糖缓解肉牛短途运输应激的效果研究

为了研究黄芪多糖缓解肉牛短途运输应激的效果,选择15头（12月龄、体重250 kg左右）健康西门塔尔杂交肉牛,随机分至对照组、运输应激组和黄芪多糖处理组中,每组5头牛,黄芪多糖处理组牛给予10 g/（d·头）的黄芪多糖,运输应激组和黄芪多糖处理组进行3 h的60 km/h模拟公路运输。运输前1 d及运输后1、7 d采集所有试验牛的血样,测定相关生化指标,同时统计肉牛日增重和发病率。结果表明,运输应激组肉牛血清Na⁺在运输后1 d显著升高（P<0.05）,对照组和黄芪多糖处理组在试验期间各时间点血清Na⁺、K⁺、Ca²⁺和Cl^-无显著差异（P>0.05）;运输应激组在运输后1、7 d的Na⁺/K⁺-ATP酶活性均极显著低于运输前1 d（P<0.01）,血清SOD活性、GSH-Px活性均显著低于运输前1 d（P<0.05）,运输后1、7 d血清MDA含量均显著高于运输前1 d（P<0.05）,对照组和黄芪多糖处理组上述指标在试验期间均无显著变化（P>0.05）;对照组和黄芪多糖处理组运输后7 d平均日增重均极显著高于运输应激组（P<0.01）,黄芪多糖处理组的呼吸道和消化道发病率均低于运输应激组。综上,黄芪多糖对肉牛短途运输应激防治具有一定的应用价值。     

高效、低毒、无残留的动物专用抗生素——泰乐菌素及其应用

泰乐菌素是由弗氏链霉菌产生的一种大环内酯类动物专用抗生素，主要有酒石酸泰乐菌素和磷酸泰乐菌素，具有抗菌谱广、临床应用范围广、促生长作用明显、毒副作用小、残留量低等特点。在兽医临床上，泰乐菌素对支原体有特效，是治疗畜禽支原体疾病的首选药物。在畜禽饲养业，泰乐菌素广泛应用于鸡、猪、牛的饲料中，能明显促进畜禽生长，提高生长速率，缩短饲养周期，提高饲料利用率和经济效益。1． 泰乐菌素的使用方法（图1） 2． 使用泰乐菌素的注意事项 1．配伍禁忌 泰乐菌素一般不与杆菌肽锌、北里霉素、维吉尼亚霉素、黄霉素、喹乙醇、…     

生物活性制剂抗牛运输应激试验研究

为了探讨以褪黑素为主要成分的生物活性制剂抗牛运输应激的效果,试验选择健康西门塔尔杂交牛36头,随机分为试验组和对照组,试验组在运输前1小时和途中分别肌肉注射生物活性制剂10 mL,对照组同时肌肉注射生理盐水10 mL,于运输前1天和运输后1天采集试验牛的血样,测定相关生理生化指标,统计发病率、死亡率,计算发病损失。结果表明:两组牛运输前与运输后体温未见明显差异(P0.05);运输后两组牛体重极显著降低(P0.01),但对照组牛体重损失较试验组牛大,两组间体重差异显著(P0.05)。运输前两组牛血液中中性粒细胞比率(NEUT)、淋巴细胞比率(LYMPH)差异不显著(P0.05);运输后两组牛血液中中性粒细胞比率极显著降低(P0.01),淋巴细胞比率极显著升高(P0.01);运输后试验组牛血液中中性粒细胞百分比、淋巴细胞百分比差异显著高于或低于对照组牛(P0.05)。试验组牛血清生化指标中的超氧化物歧化酶(SOD)活性和皮质醇(COR)、三碘甲状腺原氨酸(T3)、四碘甲状腺原氨酸(T4)含量得到显著改善(P0.05),有利于提高机体的抗氧化能力和维持氧化-抗氧化状态的平衡。试验组牛发病率、死亡率明显低于对照组;对照组牛治疗成本为试验组的10.19倍。说明生物活性制剂能改善运输应激牛免疫功能,有利于降低牛运输应激反应。     

抗体滴度可作为鸡毒支原体药物疗效的评价指标

以泰乐菌素、硫氰酸红霉素、克拉霉素、强力霉素作为供试药物,通过鸡毒支原体人工感染鸡群的治疗试验,对其药效评价方法进行比较。结果显示,对鸡毒支原体敏感性高的泰乐菌素治疗组鸡群的抗体阳性率,特别是抗体滴度明显比低敏的强力霉素组低,且抗体滴度的高低与鸡群炎症变化率呈正相关。数据表明,抗体滴度可作为鸡毒支原体药物疗效的又一种评价指标。     

桔梗等中草药合剂治疗仔猪气喘病的疗效试验

仔猪气喘病是由猪肺炎支原体引起的慢性呼吸道疾病。在畜牧业生产中,常使用抗生素类药物进行对症治疗,但效果不理想,且易产生耐药性。试验使用自行研制的中草药合剂治疗仔猪气喘病。将50头临床发病仔猪随机分为5组,每组10头,用高、中、低中草药剂量给药组、泰乐菌素组及空白对照组作对比治疗试验。结果:高剂量中草药组治愈率为60.00%,死亡率为40.00%;中剂量中草药组治愈率为70.00%,死亡率为30.00%;低剂量中草药组治愈率为40.00%,死亡率为60.00%;泰乐菌素组治愈率为50.00%,死亡率为50.00%;空白对照组治愈率为10.00%,死亡率为90.00%。综上可得,将5.5 g/kg体质量拌入饲料中饲喂的中剂量中草药合剂组在临床上对仔猪气喘病有明显的治疗效果,并且效果优于西药泰乐菌素组。     

泰乐菌素畜禽专用抗生素

泰乐菌素,别名亦称泰农、太乐霉素。泰乐菌素是１９５９年自弗氏链霉菌的培养液中获得的。其理化物性是,泰乐菌素为一种白色板状结晶,微溶呈水,呈碱性。产品为酒石酸盐、磷酸盐、盐酸盐、硫酸盐及乳酸盐等,易溶于水。水溶液在２５℃,ｐＨ５．５－７．５时可保存３个月,但是若水溶液中含有铁、铅等金属离子时,会使本品失效。对革兰氏阳性菌、泰乐菌素是一种大环内酯类抗生素,革兰氏阴性菌都具有很高的杀灭作用。同时,还有明显的抗支原体作用,对畜禽支原体疾病有很好的治疗作用,特别坚支原体疾病治疗有特效,成为治疗支原体疾病的…     

A field study of Mycoplasma bovis infection in cattle

After an outbreak of mastitis in cattle caused by Mycoplasma bovis a study was made in 5 herds with recent cases (principal herds) and in 4 control herds. In the principal herds, M. bovis was isolated from milk samples, nasal swabs, and from one vaginal swab. M. bovis was also isolated from nasal swabs of calves in 2 of the 4 control herds, whereas all milk samples and vaginal swabs from the control herds were negative. Evaluation of serum antibody titres to M. bovis among non-mastitic animals of 3 principal herds and 1 control herd showed no difference in distribution of the titre values, which generally were low. However, cows excreting M. bovis in the milk had high antibody titres. The way of introduction to the herds and the spread of the infection within the herds could not be established by the study, which was supplemented by a DNA restriction fragment analysis of a number of M. bovis isolates.     

Effect of Astragalus Polysaccharides on Short-distance Transport Stress in Beef Cattle

To study the effect of Astragalus polysaccharide on short-distance transport stress in beef cattle,15 healthy and 12-month-old Simmental crossbred beef cattle were selected and randomly divided into control group,transport stress group and Astragalus polysaccharide test group with 5 cattles in each group.The cattles in Astragalus polysaccharide test group were fed with 10 g/d per head Astragalus polysaccharide during the experimental period.The cattles both in transport stress group and Astragalus polysaccharide test group were transported for 3 h at the speed of 60 km/h, and blood samples were collected and used for measuring some biochemical parameters. The daily gain and morbidity were measured simultaneously. The results showed that,in transport stress group,serum Na⁺ increased significantly in 1 d after transportation comparing to before transportation (P<0.05). serum Na⁺, K⁺, Ca²⁺ and Cl^- showed no significant difference during the experimental period in control group and Astragalus polysaccharide test group (P>0.05).After transport (1 and 7 d),blood Na⁺/K⁺-ATP activities were extremely significantly decreased (P<0.01), SOD and GSH-Px activities were significantly decreased (P<0.05), while serum MDA contentswere significantly increased (P<0.05) in transport stress group comparing with that at 1 d before transport.These indicators of the control and Astragalus polysaccharide test group showed no significantly difference during the experimental period (P>0.05); 7 d average daily gain after transportation of control group and Astragalus polysaccharide test group were extremely significantly higher than transport stress group (P<0.01), incidence rates of respiratory and gastrointestinal of Astragalus polysaccharide test group was lower than transport stress group. The results demonstrated that Astragalus polysaccharide could be applied to the transport stress for prevention and treatment in beef cattle.     

Laboratory diagnosis of Mycoplasma infection in young cattle

The aim of this study was to detect Mycoplasma species in the respiratory tract of 110, 310 and 510 day-old groups of cattle by serological, bacteriological and histopathological investigations. Antibodies against M. bovis were found in 75% of the 110 day-old, in 50%--of the 310 day-old and in 55%--of the 510 day-old groups of cattle. Bacteriological examination of the samples from nasal cavities revealed that Mycoplasma carriers were found in 60% of the 110 day-old group of cattle, 40% of the 310 day-old and 40% of the 510 day-old group of cattle. Using the PCR method Mycoplasma was isolated from 25% of lung samples of the 510 day-old group of cattle. Mycoplasma bovis and Mycoplasma dispar were confirmed by serological investigations. Foci of bronchointerstitial pneumonia were determined by histopathological examination in 27.5% of lung samples. Mycoplasma bovis was isolated in 72.7% of bronchointerstitial pneumonia cases. Data processing with an SPSS 13.0 statistical package led to the conclusion that Mycoplasma bovis was found more frequently in the 110 day-old group of cattle (the youngest age group in this study) rather than in the 310 and 510 day-old groups of cattle (chi2 = 6.531; p = 0.038). The results obtained led to the conclusion that serological, bacteriological and histopathological examinations are important in detecting particular animal--carriers of Mycoplasma.     

Antibiotic susceptibilities of recent isolates of Mycoplasma bovis in Belgium

The susceptibilities of 40 recent Belgian field isolates of Mycoplasma bovis to 10 antimicrobial agents were assessed. Tiamulin was the most active antimicrobial agent against M bovis, with an initial inhibitory concentration (IIC50) of 0.06 microg/ml, but it is not licensed for the treatment of cattle. All three fluoroquinolones tested (danofloxacin, enrofloxacin and marbofloxacin) were effective against strains of M bovis, and had a minimum mycoplasmacidal concentration (MMC50) less than or equal to 1 microg/ml. Gentamicin was poorly effective, having an IIC50 of 8 microg/ml. Many strains of M bovis were resistant to tylosin, spectinomycin, lincomycin, tetracycline and oxytetracycline.     

牛支原体新疆分离株P48基因的克隆、原核表达及重组蛋白免疫原性研究

试验旨在确定牛支原体P48基因的免疫原性，为进一步筛选牛支原体免疫保护性基因奠定基础。本研究以牛支原体新疆分离株为研究对象，运用Overlap PCR方法扩增得到点突变后的牛支原体新疆分离株P48基因，构建原核表达载体pET-32a （+）-P48，转化大肠杆菌BL21（DE3）感受态细胞，在诱导剂ITPG的诱导下获得重组蛋白P48，纯化后的重组P48蛋白免疫BALB/c小鼠制备多克隆抗体，运用Western blotting和ELISA方法验证其反应原性和免疫原性。结果表明，试验成功构建原核表达载体pET-32a （+）-P48，重组蛋白P48大小约为66 ku，纯化后的牛支原体P48重组蛋白免疫小鼠后可产生良好的免疫反应，血清抗体滴度达到较高水平（D_{450 nm}值为1.126）。Western blotting结果显示，抗牛支原体P48重组蛋白的鼠血清与牛支原体P48重组蛋白及牛支原体全菌蛋白抗原均能产生明显的抗原抗体反应，表明P48重组蛋白具有良好的免疫原性与反应原性，可作为牛支原体新型疫苗的候选基因，且牛支原体新疆分离株P48基因与国内外5株牛支原体P48基因的同源性很高，亲缘关系较近。     

Development of a monoclonal blocking ELISA for the detection of antibody to Mycoplasma bovis in dairy cattle and comparison to detection by PCR

A monoclonal antibody blocking enzyme-linked immunosorbent assay (B-ELISA) was developed to detect antibodies to Mycoplasma bovis in cattle sera. The assay was highly specific and sensitive and there was no cross-reaction detected. This method revealed a high prevalence of antibodies (60%) to M. bovis in dairy cattle in North Queensland. The diagnostic potential of this B-ELISA for the detection of antibody to M. bovis was compared with its detection by PCR. There was a strong positive correlation between PCR and B-ELISA titers. Thus, the B-ELISA appears to be a valuable and reproducible tool in the serodiagnosis of M. bovis infection in cattle.     

Mycoplasma species and related organisms isolated from ruminants in Britain between 1990 and 2000

Between 1990 and 2000, more than 1600 mycoplasmas and the related acholeplasmas were identified from ruminant animals by the Mycoplasma Group at the Veterinary Laboratories Agency--Weybridge. Mycoplasma bovis was the most commonly identified pathogen, mostly from pneumonic calves but occasionally from cattle with mastitis and arthritis. Mycoplasma canis was first isolated in Britain in 1995 from pneumonic calves and the number of isolates increased to 18 per cent of the total mycoplasmas isolated from cattle in 1999. The ELISA for antibodies to M. bovis detected 1971 positive samples (22 per cent) among 8959 serum samples, mainly from pneumonic cattle. Other mycoplasmas identified included Mycoplasma dispar from the lungs of cattle with respiratory disease, and Mycoplasma bovigenitalium from the reproductive tract of cows with vulvovaginitis and infertility. Mycoplasma bovirhinis and Acholeplasma species were found commonly but are thought to be more opportunistic than pathogenic. In sheep and goats, the majority of Mycoplasma species isolated were identified as Mycoplasma ovipneumoniae from pneumonic sheep, Mycoplasma conjunctivae from sheep with keratoconjunctivitis, and the ubiquitous Mycoplasma arginini.