鹰嘴豆对小鼠的抗氧化作用研究

通过检测丙二醛(MDA)、蛋白质羰基、超氧化物歧化酶(SOD)、还原性谷胱甘肽(GSH)等指标含量,探究鹰嘴豆对D-半乳糖所致衰老模型小鼠的抗氧化作用。结果显示,鹰嘴豆中剂量组小鼠体重增长速度较快,其余各组差异不大;模型组小鼠丙二醛、蛋白质羰基含量与空白对照组相比差异显著(P0.05),SOD活力和GSH含量显著降低(P0.05);给药组小鼠MDA含量下降明显,与模型组相比差异极显著(P0.01),SOD活力升高,其中鹰嘴豆高、中剂量组差异显著(P0.05),GSH含量虽有升高的趋势,但无显著差异(P0.05)。提示鹰嘴豆对D-半乳糖所致衰老小鼠有一定的抗氧化作用。     

GPA对小鼠肝损伤血清及肝组织中GOT、GPT的影响

采用刀豆蛋白A（ConA）尾静脉注射方法建立小鼠免疫性肝损伤模型,分别用低（100mg/kg）、中（200mg/kg）、高（400mg/kg）3个不同剂量大蒜多糖（GPA）对小鼠进行灌胃,灌服7d后,小鼠尾静脉注射刀豆蛋白A,采血及取肝组织,用赖氏法测定天冬氨酸转氨酶（GOT）及丙氨酸转氨酶（GPT）变化。结果模型组和多糖组与空白组比较,除高浓度多糖组差异不显著（P〉0.05）外,其它各组均差异显著（P〈0.05）,且多糖组与模型组比较差异显著（P〈0.05）,并呈现一定的量效关系。表明不同浓度的大蒜多糖均对ConA致小鼠免疫性肝损伤具有保护作用。     

大蒜多糖对ConA致小鼠肝损伤保护作用组织学观察

探讨大蒜多糖（GPA）对刀豆蛋白A（ConA）诱导的小鼠免疫性肝损伤的保护作用和对肝糖原的影响。将40只小鼠随机分为5组,即空白对照组、模型组、不同剂量多糖组（100、200、400mg／kg）。空白对照组和模型组小鼠灌胃生理盐水,多糖组小鼠分别以相应剂量灌胃,至第7天处死前8h,除空白对照组外所有小鼠尾静脉注射ConA,以制造急性免疫性肝损伤,取肝组织,进行病理学观察。结果模型组小鼠肝组织变性、坏死、瘀血等损伤严重,细胞界线与细胞核模糊不清,肝糖原含量减少,多糖组小鼠肝组织损伤均明显较轻,肝细胞界线清晰,糖原含量减少不显著,100mg／kg多糖组接近正常水平。研究表明,大蒜多糖能够促进肝糖原合成和储存,对小鼠免疫性肝损伤有良好的保护作用。     

丹参多糖对免疫性肝损伤小鼠肝脏过氧化指标、炎症细胞因子和ICAM-1的影响

将SPF级雄性昆明小鼠随机分成正常对照组,LPS模型组,丹参多糖低、中、高剂量组和阳性药物对照组。灌胃相应药物12 d后,腹腔注射LPS和D-GalN建立小鼠免疫性肝损伤模型。检测各组小鼠肝组织中SOD、MDA、GSH-Px水平,比较造模1,3 h后各组小鼠肝组织中IL-1β、IL-6、TNF-α的含量变化以及测定肝组织ICAM-1蛋白的表达水平。结果显示,与正常对照组比较,LPS模型组小鼠肝组织中MDA含量显著升高,SOD、GSH-Px活性显著降低, IL-1β、IL-6、TNF-α含量以及ICAM-1蛋白表达水平均显著升高(P<0.01);与LPS模型组相比,丹参多糖各剂量组和阳性药物对照组小鼠肝组织中MDA含量显著降低,SOD、GSH-Px活性显著升高,IL-1β、IL-6、TNF-α含量以及ICAM-1蛋白表达水平均显著降低(P<0.05或P<0.01);各用药组之间相比较,丹参多糖中、高剂量组和阳性药物对照组调控过氧化指标、炎症细胞因子和ICAM-1效果最显著(P<0.05或P<0.01)。结果表明,丹参多糖具有明显缓解小鼠免疫性肝损伤的作用,其机制可能与拮抗肝脏脂质过氧化反应,降低肝组织中炎症细胞因子含量及ICAM-1蛋白表达有关。     

地锦粗提物对脾虚小鼠抗氧化能力影响的试验

为了探讨地锦粗提物对脾虚小鼠脏器抗氧化能力的影响.采用泻下加劳倦过度的方法建立脾虚模型,造模时间为60d,期间测定谷胱甘肽过氧化物酶(GSH-PX)和血浆淀粉酶活性,二者活性显著降低后为脾虚模型建立.建立脾虚模型前和脾虚模型建立后相比较:脾虚组和地锦组小鼠的血浆淀粉酶活力均降低,均差异显著(P＜0.05);脾虚组和地锦组的血浆GSH-PX活力均降低,差异显著(P＜0.05)或极显著(P＜0.01).将脾虚模型小鼠随机分为脾虚组和地锦组,同时设对照组.地锦组每天给予地锦水煎剂30 g/(kg·bw),脾虚组和对照组给予相同剂量的生理盐水,试验期为60d.试验结束后,剖杀各组小鼠,取内脏,测超氧化物歧化酶(SOD)的活性和丙二醛(MDA)的含量.结果表明,脾虚组和地锦组小鼠各脏器SOD的活力均低于对照组,差异显著(P＜0.05)或极显著(P＜0.01),且随地锦粗提物试验期的增加,地锦组小鼠SOD的活力较脾虚组高,差异显著(P＜0.05);脾虚组和地锦组MDA的含量较对照组高,且差异显著(P＜0.05)或极显著(P＜0.01),随地锦粗提物试验期的增加,脾虚组MDA的含量较地锦组高,差异显著(P＜0.05).表明地锦水煎剂粗提物可明显提高脾虚症状小鼠抗氧化能力.     

三种栓剂治疗奶牛子宫内膜炎的疗效比较

为了比较中药栓、复方碘栓、生物栓对奶牛子宫内膜炎的治疗效果,对30头患子宫内膜炎的奶牛分别子宫投放3种栓剂,观察用药前后的临床症状,并于第0,2,4,6,8天测定血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力和丙二醛(MDA)含量。结果表明:给药后患病奶牛阴门分泌物明显减少。第6天复方碘栓治疗组血清SOD活力极显著升高(P0.01),GSH-Px活力显著升高(P0.05),MDA含量极显著降低(P0.01)。第8天生物栓治疗组血清SOD活力显著升高(P0.05),GSH-Px活力极显著升高(P0.01),MDA含量极显著降低(P0.01);而中药栓治疗组血清GSH-Px活力显著升高(P0.05),MDA含量极显著降低(P0.01)。     

核转录因子NF-E2相关因子基因缺失对高脂饲粮诱导非酒精性脂肪肝模型小鼠肝脏的影响

本试验旨在研究敲除核转录因子NF-E2相关因子(Nrf2)对高脂饲粮诱导小鼠肝脏氧化应激的影响。选择雄性野生型(WT)和Nrf2基因敲除(KO)ICR小鼠各20只,分别随机分成2组,每组各10只。1组WT和1组KO小鼠饲喂普通饲粮,为对照组,另2组饲喂高脂饲粮,为高脂组。试验期8周。结果显示,1)与对照组相比,WT和KO高脂组小鼠血清总胆固醇(TC)、低密度脂蛋白(LDL)含量和谷丙转氨酶(ALT)、谷草转氨酶(AST)活性极显著升高(P0.01),碱性磷酸酶(ALP)活性显著或极显著升高(P0.05或P0.01),总蛋白(TP)含量极显著降低(P0.01),但甘油三酯(TG)和高密度脂蛋白(HDL)含量变化不显著(P0.05)。2)WT高脂组小鼠肝脏表现出小泡性脂肪变性,KO高脂组小鼠肝脏表现出严重的大泡性脂肪变性和温和的小泡性脂肪变性。3)与对照组相比,WT和KO高脂组小鼠肝脏中谷胱甘肽(GSH)含量和超氧化物歧化酶(SOD)活性显著或极显著降低(P0.05或P0.01),而过氧化物酶(POD)活性和丙二醛(MDA)含量显著或极显著升高(P0.05或P0.01)。与WT小鼠相比,KO高脂组小鼠肝脏中MDA含量增加49%,但GSH含量及SOD、POD活性变化不显著(P0.05)。与WT对照组小鼠相比,KO高脂组小鼠肝脏中SOD、POD活性和MDA含量显著或极显著升高(P0.05或P0.01),而GSH含量极显著降低(P0.01)。由此可见,高脂诱导Nrf2基因缺失小鼠发生较严重的脂肪变性,同时高脂饲粮诱导的非酒精性脂肪肝模型小鼠肝脏发生氧化应激。     

铅对蛋鸡肾脏的氧化损伤及酵母硒的保护效应研究

试验采用90只40周龄海兰褐蛋鸡进行饮水铅(Pb)染毒(100 mg Pb/L)和酵母硒保护(100 mg Pb/L+3％酵母硒)试验,为期8周,通过检测蛋鸡肾脏组织中抗氧化指标和微量元素含量变化及超微结构来探讨铅对蛋鸡肾脏的毒性损伤及酵母硒的保护效应.结果表明,与对照组相比,Pb组和酵母硒组超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和谷胱甘肽(GSH)含量均显著或极显著降低(P＜0.05或P＜0.01),丙二醛(MDA)含量显著或极显著升高(P＜0.05或P＜0.01);Pb组和酵母硒组肾组织中Cu、Zn含量显著降低(P＜0.05),Pb组Fe含量极显著升高(P＜0.01),硒含量显著降低(P＜0.05);酵母硒组铁含量无显著差异(P＞0.05) 与Pb组相比,酵母硒组SOD活性、GSH含量显著升高(P＜0.05),MDA含量显著降低(P＜0.05),肾组织中铜、锌、硒含量显著或极显著升高(P＜0.05或P＜0.01) 超微结构观察发现,铅染毒使蛋鸡肾组织中细胞核染色质边集,有大量畸形核,线粒体肿胀变形,部分嵴断裂,溶解;保护组损伤变化轻微.综上所述,酵母硒对铅暴露所致蛋鸡肾毒性损伤具有一定的保护效应.     

樗白皮提取物对腹泻模型小鼠抗氧化能力的影响

为研究腹泻病理状态下樗白皮提取物对机体氧化还原状态的调节功能,采用番泻叶提取物建立小鼠药物性腹泻模型,经不同剂量樗白皮提取物治疗,对小鼠血清中MDA、SOD、GSH、GSSG、GSH-Px等抗氧化指标进行测定。结果显示,模型组MDA含量较正常组显著升高(P0.05),樗白皮提取物不同剂量治疗组均低于模型组,与治疗对照组无显著差异;模型组SOD酶活性显著低于其他各组(P0.01),正常对照组与其他实验组之间无显著差异;模型组GSH含量显著低于正常对照组和治疗对照组(P0.05),高剂量组和中剂量组高于模型组(P0.05),低剂量组与模型组无显著差异;正常对照组GSSG含量显著低于其他各组(P0.01),模型组显著高于治疗对照组和高剂量组(P0.01),高于中剂量组和低剂量组(P0.05);GSH-Px模型组均低于其他各组,除与低剂量组无显著差异外,与其他各组差异均极显著(P0.01)。结果表明,樗白皮提取物能够降低腹泻模型小鼠体内氧化性物质含量,提高还原酶活性及促进还原性物质生成,对机体的氧化还原稳态具有一定的调节作用,并且与给药剂量之间存在一定的量效关系。     

槲皮素对镉致大鼠肝脏损伤的研究

为了研究镉致大鼠肝脏损伤及槲皮素对损伤的作用,试验以SD大鼠为研究对象,将20只大鼠随机分为4组,即空白对照组、镉处理组、槲皮素组和镉+槲皮素组。6周后,采集血清并处死大鼠,取肝脏组织并制成匀浆液,检测血清中天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)活性,肝脏中丙二醛(MDA)、还原型谷胱甘肽(GSH)含量及过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSHPx)、超氧化物歧化酶(SOD)活性。结果表明:与空白对照组比较,镉处理组AST、ALT活性极显著升高(P0.01),MDA含量显著升高(P0.05),GSH含量极显著降低(P0.01),GSH-Px、CAT、SOD活性显著或极显著降低(P0.05或P0.01);与镉处理组比较,镉+槲皮素组AST、ALT活性显著或极显著降低(P0.05或P0.01),MDA和GSH含量分别显著降低和升高(P0.05),GSH-Px、CAT、SOD活性显著或极显著升高(P0.05或P0.01)。说明槲皮素能保护由镉导致的肝脏损伤。     

不同配比关系的丙酮酸乙酯复方混悬剂在细菌感染模型中的比较研究

利用青岛农业大学动物医学实验室研制的4种不同配比关系的丙酮酸乙酯（EP）复方混悬剂,对大肠杆菌感染小鼠进行治疗试验,以得到EP与头孢噻呋（CE）的最佳配比量,选出一个最佳组方,并比较不同的EP剂量、给药时间对治疗结果的影响。试验将340只昆明小鼠随机分17组,每组20只,注射大肠杆菌ATCC 25922菌液后,分别于1、4、8 h注射4种EP复方混悬剂（EP分别为40、80、120、160 mg/kg）和1种CE单方混悬剂（CE为5 mg/kg）。观察各组小鼠7 d内的死亡情况并做统计学分析。结果显示,攻毒后1和4 h进行治疗,EP为40、80 mg/kg的复方混悬剂治疗效果显著优于CE单方混悬剂（P<0.05）,但2种EP复方混悬剂间无显著差异（P>0.05）。攻毒后8 h进行治疗,注射4种EP复方混悬剂和1种CE单方混悬剂均无显著治疗效果（P>0.05）,且与阳性对照组相比差异不显著（P>0.05）。结果表明,在小鼠大肠杆菌攻毒试验中,EP 40和80 mg/kg的复方混悬剂治疗效果明显优于CE单方混悬剂,能显著提高小鼠治愈率,2种复方混悬剂间无明显差别,但从更安全、更经济的角度考虑选择低剂量的EP 40 mg/kg复方混悬剂更为合适。     

山豆根多糖对感染PRRSV小鼠脾脏细胞因子水平的影响

探讨山豆根多糖对PRRSV感染小鼠脾淋巴细胞分泌细胞因子水平的影响。将70只昆明种小鼠随机分为7组(A组、B组、C组、D组、E组、F组、G组),每组10只,雌雄各半,依据前期已经建立氧化应激模型的感染条件,D组、E组、F组、G组小鼠于试验第1、2、3天分别采用口服、滴鼻和腹腔注射3种途径联合感染PRRSV病毒原液1.0mL/只,A组、B组、C组给予生理盐水1.0mL/只。第4、5、6天,A、D组小鼠分别腹腔注射生理盐水,0.2mL/10g。B组小鼠腹腔注射5.0mg/kg的脂多糖(LPS)溶液,C组、E组、F组、G组小鼠分别腹腔注射不同剂量的山豆根多糖(200、50、100、200mg/kg)。供试小鼠均于第14天处死,并取其脾脏制备匀浆。采用ELISA检测脾匀浆中TNF-α、IL-1β、IL-6、IL-8、IL-10和MCP-1等细胞因子的水平。结果显示,PRRSV感染小鼠后能升高小鼠脾脏匀浆内TNF-α、IL-1β、IL-6、IL-8、IL-10和MCP-1水平,50mg/kg~100mg/kg剂量的山豆根多糖能降低上述细胞因子的水平。结果表明,山豆根多糖能有效降低PRRSV感染小鼠脾脏细胞因子的水平。     

The effect of tiletamine/zolazepam (Zoletile) combination with xylazine or medetomidine on electroencephalograms in dogs

The effects of xylazine or medetomidine on tiletamine/zolazepam (Zoletile) anesthesia were evaluated by changes in the canine electroencephalogram (EEG). Experimental groups were three: the group treated with 10 mg/kg of Zoletile intravenously (TZ), the group treated with 1.1 mg/kg of xylazine intramuscularly and 10 mg/kg of Zoletile intravenously (XTZ), and the group treated with 30 microg/kg of medetomidine intramuscularly and 10 mg/kg of Zoletile intravenously (MTZ). EEG recording electrode was positioned at Cz, which was applied to International 10-20 system. For all recording times, the powers of each band (band 1: 1-2.5 Hz, band 2: 2.5-4.5 Hz, band 3: 4.5-8 Hz, band 4: 8-13 Hz, band 5: 13-20 Hz, band 6: 20-30 Hz, band 7: 30-50 Hz, band 8: 1-50 Hz) were calculated. In TZ, at 10 min after Zoletile injection, the powers of bands 3, 4, 5 and 8 significantly decreased. At 20 min after Zoletile injection, the powers of band 1 and 8 were significantly decreased. After Zoletile injection, there were significant decreases in bands 1, 4, 5, 6, 7 and 8 in XTZ, and in bands 1, 3, 4, 5, 6, 7 and 8 in MTZ. These significant changes disappeared in all band powers in TZ and MTZ in the last 1 min just prior to the dogs showing head-up movement. But, in XTZ, all band powers, except band 2, were significantly reduced. EEG power spectral analysis revealed the differences in band powers on awakening, even though the same kind of drugs were used. We thought that was a useful method to compare the effect of xylazine and medetomidine on Zoletile-induced anesthesia in dogs.     

Effects of four anaesthetic protocols on the neurological and cardiorespiratory variables of puppies born by caesarean section

Twenty-four bitches which had been in labour for less than 12 hours were randomly divided into four groups of six. They all received 0.5 mg/kg of chlorpromazine intravenously as premedication, followed 15 minutes later by either 8 mg/kg of thiopentone intravenously (group 1), 2 mg/kg of ketamine and 0.5 mg/kg of midazolam intravenously (group 2), 5 mg/kg of propofol intravenously (group 3), or 2.5 mg/kg of 2 per cent lidocaine with adrenaline and 0.625 mg/kg of 0.5 per cent bupivacaine with adrenaline epidurally (group 4). Except for group 4, the bitches were intubated and anaesthesia was maintained with enflurane. The puppies' heart and respiratory rates and their pain, sucking, anogenital, magnum and flexion reflexes were measured as they were removed from the uterus. The puppies' respiratory rate was higher after epidural anaesthesia. In general the puppies' neurological reflexes were most depressed after midazolam/ketamine, followed by thiopentone, propofol and epidural anaesthesia.     

A toxicity study of eltenac, a nonsteroidal anti-inflammatory drug, in horses

A double-blind study was performed, in horses, to determine the potential toxic effects of the nonsteroidal anti-inflammatory drug, eltenac(4-[(2,6-dichlorophenyl) amino]-3-thiopheneacetic acid). Four treatment groups of six horses were formed. The drug was injected intravenously, once daily, at a dose level of 0.5 mg/kg, 1.5 mg/kg or 2.5 mg/kg for 15 days. A control group was injected with sterile saline solution. Horses were monitored for changes in appetite, physical examinations, biochemical evaluations and gastroscopic examinations. Complete post-mortem examinations were also performed. A few glandular gastric ulcers, mild in severity, developed in seven animals during the treatment period. This occurred more often in horses treated with high doses of eltenac ( P = 0.02). A dose-dependent change of white blood cell (WBC) count and neutrophil count was noted. Total protein, albumin and globulin levels had dose-dependent decreases. One horse in the high dose group (2.5 mg/kg) developed ventral ooedema as well as hypoproteinaemia. Gross post-mortem and histological examination did not reveal any signs of drug related gastrointestinal, renal or hepatic abnormalities. Toxic effects of eltenac given intravenously were greatest in horses treated with 2.5 mg/kg of the compound for 15 days compared to other groups.     

微囊化与非微囊化胆囊收缩素卵黄抗体对小鼠促生长免疫效果的比较研究

试验选用70只健康小鼠随机分为7组,每组10只。试验1~7组分别为口服0 mg/kg胆囊收缩素（cholecystokinin,CCK）对照组、口服0 mg/kg空囊组、口服1 mg/kg CCK-卵黄抗体（yolk immunoglobulin,IgY）-低剂量微囊组、口服5 mg/kg CCK-IgY-高剂量微囊组、注射0 mg/kg CCK对照组、注射1 mg/kg CCK-IgY-低剂量非微囊组、注射3 mg/kg CCK-IgY-高剂量非微囊组。单笼饲养,试验期40 d。以小鼠体重、日采食量及血液中CCK抗体D值为评价指标,对CCK-IgY及其微胶囊进行促生长及免疫效果比较研究。结果表明,从试验全期来看,试验3组平均体重和平均日采食量均极显著高于试验4组（P<0.01）,但与试验1组相比差异不显著（P>0.05）;随着注射CCK-IgY剂量的增加,D值也随之升高,试验7组D值极显著高于试验5组（P<0.01）,而CCK-IgY微囊组均未达到与注射一致的效果。口服微囊化CCK-IgY和腹腔注射非微囊化CCK-IgY均可刺激机体产生相应的免疫应答反应,腹腔注射非微囊化CCK-IgY具有较明显的促生长效果,但CCK-IgY微囊饲喂效果不够明显,需进一步研究。     

纳米氧化铜对小白鼠血浆抗氧化机能的影响

选144只20g左右的健康昆明种小白鼠,随机分为6组,每组设4个重复。1组饲喂基础日粮;2组在基础日粮中以硫酸铜的形式添加铜10mg/kg;3组在基础日粮中以氧化铜的形式添加铜10mg/kg;4～6组在基础日粮中以纳米氧化铜的形式分别添加铜5、10、20mg/kg。研究不同剂量纳米氧化铜对小白鼠血浆抗氧化能力的影响,试验期30d。结果表明,添加纳米氧化铜显著提高小白鼠血浆铜蓝蛋白活力(P<0.05),显著提高小白鼠血浆细胞色素C氧化酶活性(P<0.05),显著降低30d小白鼠血浆丙二醛含量(P<0.05)。     

Evaluation of the influence of meloxicam and flunixin meglumine on the apoptosis of peripheral blood CD4+ and CD8+ T cells in calves

The aim of the study was to determine whether treatment with recommended doses of meloxicam or flunixin had an effect on the apoptosis of peripheral blood T lymphocytes in calves. The study was carried out on 4-5 months old calves (n = 24, 8 per group). Experimental animals were injected subcutaneously with a single dose of 0.5 mg x kg(-1) of meloxicam or intravenously with 3 doses of 2.2 mg x kg(-1) day(-1) of flunixin. The non-treatment animals served as control. Blood samples were taken at day 0 and at days 1, 2, 3, 5, 7 and 14 after the first NSAIDs injection. Apoptosis was determined by flow cytometry using Annexin V-PE/7-AAD staining. The kinetic analysis of apoptosis in the total lymphocyte population, as well as in the CD4+ and CD8+ subsets did not reveal significant differences in the frequency of early apoptotic cells between control and experimental groups throughout the period studied. Although, 24 h after administration of the first dose of NSAIDs, late-stage apoptosis/necrosis was significantly increased in the total lymphocyte population (the meloxicam group), as well as in the CD4+ (the meloxicam group and the flunixin group) and CD8+ (the flunixin group) subsets of T cells. However, this disturbance was transient, relatively poorly expressed and, thus, unlikely to be of clinical significance. Our results indicate that the use of meloxicam or flunixin in accordance with the recommended dosage regimen in cattle do not have a clinically significant influence on apoptosis of peripheral blood T cells.     

A field comparison of the efficacy and tolerance of marbofloxacin in the treatment of bovine respiratory disease

A multicentre, controlled, randomized and blinded trial was carried out in 180 ruminating calves with pyrexia and respiratory sign(s) on nine Belgian, British and French farms. All animals were sampled for pathogenic bacteria before treatment and at failure/relapse. Calves were injected with either marbofloxacin (M) solution [Marbocyl (Laboratoire Vétoquinol, Lure, France) 10%] at 2 mg/kg/24 h for 4 days intravenously on the first day then subcutaneously, or tilmicosin (T) solution (Micotil, Elanco Products Ltd, Basingstoke, Hants, UK) at 10 mg/kg as a single subcutaneous (s.c.) injection. The animals were examined clinically eight times up to day 28. The bacterial pathogens were found to be sensitive to marbofloxacin: for Pasteurella haemolytica the minimum inhibitory concentration (MIC)90 was 0.08 microg/mL and for P. multocida the MIC90 was 0.04 microg/mL. Cure rates at day 4 for group M and group T were 84 vs. 82%, respectively (P > or = 0.05). However, overall clinical score was significantly lower after 1 day in group M (P < 0.05). There was no difference in either relapse rate or average daily weight gain between groups. Marbofloxacin was found to be better tolerated than tilmicosin at the s.c. injection site (77.5 vs. 42.2% calves without local swelling, P=0.001) and was well tolerated when injected intravenously. Marbofloxacin was shown to have comparable but faster efficacy and better local tolerance than tilmicosin in the treatment of bovine respiratory disease (BRD).