盐酸头孢噻呋乳房注入剂对干乳期奶牛的安全性分析

为研究盐酸头孢噻呋乳房注入剂对干乳期奶牛临床使用的安全性,开展药物对健康奶牛的安全性研究,作者选择健康泌乳期奶牛12头(初产和经产各6头),四个乳区分别单次给予盐酸头孢噻呋乳房注入剂一支(规格10mL:500mg)。比较奶牛用药前后直肠温度、日产奶量、牛奶体细胞数和乳区病原菌的变化。整个试验期间对给药奶牛进行连续观察,记录是否出现红、肿、热、痛等临床症状。结果显示,与给药前相比,奶牛的直肠温度、日产奶量、牛奶体细胞数均无显著变化(P0.05),乳区病原菌数量有所减少,同时,没有增加新的病原菌。结果表明,盐酸头孢噻呋乳房注入剂对干乳期奶牛正常体温、产奶量、奶中体细胞数和乳区菌群没有不良影响,该制剂用于奶牛是安全的。     

硫酸头孢喹肟乳房注入剂对泌乳期奶牛的安全性研究

为研究硫酸头孢喹肟乳房注入剂对泌乳期奶牛的安全性,试验选用12头健康泌乳奶牛(6头初产、6头经产),间隔12 h对每头奶牛的4个乳区分别注入硫酸头孢喹肟乳房注入剂(规格:8 g:75 mg/支)1支,连续给药3次,比较观察给药前后奶牛的临床症状、体细胞数、日产奶量及乳区病原菌变化情况。结果显示,与给药前相比,给药期间及停药后奶牛的临床症状、体细胞数、日产奶量、乳区病原菌检测结果均无显著性差异(P>0.05)。表明硫酸头孢喹肟乳房注入剂对泌乳期奶牛是安全的。     

利福昔明乳房注入剂对干奶期奶牛临床型乳房炎预防效果观察

本试验旨在观察利福昔明乳房注入剂对干奶期奶牛临床性乳房炎的预防效果.选择非临床型乳房炎的泌乳末期健康奶牛共计75头,随机分为空白对照组(不给药对照组),苄星氯唑西林乳房注入剂对照组(600 mg/乳区),利福昔明高(400 mg/乳区)、中(200 mg/乳区)、低(100 mg/乳区)三个剂量组,每组15头.分别在干乳期、泌乳期进行乳房观察,并采用致病菌的分离培养和乳汁中体细胞计数检测临床型乳房炎发生情况.结果表明,利福昔明低剂量组保护率与空白对照组保护率相比差异显著(P＜0.05),苄星氯唑西林对照组、利福昔明中剂量组、高剂量组对干奶期奶牛临床型乳房炎的预防效果与空白对照组相比,差异极显著(P＜0.01);利福昔明高、中剂量组与苄星氯唑西林对照组之间的预防效果差异不显著(P＞0.05).结果提示,利福昔明乳房注入剂对临床型奶牛乳房炎有较好的预防效果,可以作为预防类药物用于奶牛生产中,降低奶牛乳房炎的发生率.     

利福昔明悬乳剂在奶牛牛乳和血液中的药代动力学研究

为探讨利福昔明悬乳剂灌注泌乳期奶牛乳房后在奶牛乳区的分布情况,进行了奶牛牛乳和血液中药物的药代动力学研究。试验选取6头荷斯坦奶牛,每头奶牛随机选择2个乳区,以每个乳区200 mg的剂量进行单次乳房灌注利福昔明悬乳剂,利用高效液相色谱法检测牛乳与血液中利福昔明的含量。结果表明:利福昔明悬乳剂采用单次乳房灌注给药后,给药乳区36 h内乳头中利福昔明的浓度都在2μg/mL以上,且血液中未检出利福昔明。说明药物主要集中在给药乳区,进入体循环的量极少,并且能在较长时间内具有抑菌作用。     

奶牛乳汁体细胞数的快速检测及其临床意义

本文用新型便携式体细胞计数仪C-Reader对奶牛乳汁体细胞数(SCC)进行快速、精确地检测,同时对乳样中的病原菌进行分离鉴定,旨在指导奶牛乳房炎的诊断、预防及治疗。选用北京及河北地区10个奶牛场的111头奶牛共428份奶样,进行SCC计数。SCC20万/mL的奶样占63.6%,SCC介于20万/mL～50万/mL的奶样占13.1%,SCC50万/mL占23.3%。检测的111头奶牛中,60头奶牛患有隐性乳房炎,头发病率54.1%,乳区发病率23.3%。隐性乳房炎SCC变化范围50.6万/mL～984.3万/mL。对隐性乳房炎乳样进行致病菌分离培养,其阳性率高达82.0%。共鉴定出100株致病菌,其中金黄色葡萄球菌64株,表皮葡萄球菌11株,大肠杆菌8株,链球菌10株,其他菌7株。结果表明,C-Reader计数仪能够快速准确地检测北京及河北地区的奶牛隐性乳房炎,其病原菌以金黄色葡萄球菌为主。     

乳房炎对中国荷斯坦牛测定日泌乳性能及体细胞数变化的影响

旨在研究乳房炎及病原菌组成对中国荷斯坦牛测定日泌乳性能及体细胞数变化的影响.本研究于2009年9月对江苏某奶牛场140头成年中国荷斯坦泌乳牛进行乳房炎检测和DHI测定,同时对隐性乳房炎阳性乳区进行病原菌分离鉴定,并分析了不同乳房炎类型和隐性乳房炎病原菌组成对测定日泌乳性能和乳中SCC变化的影响.结果表明,该牛场临床乳房炎、隐性乳房炎和正常奶牛比例分别为10.00％、51.10％和37.90％,其中隐性乳房炎以大肠杆菌和链球菌混合感染最多(19头,占26.00％),其次为链球菌单独感染(17头,占23.30％).由1种细菌单独感染的比例为26头(占36.11％),2种或2种以上细菌混合感染为44头(占61.11％).乳房炎类型对测定日产奶量、乳糖含量、体细胞数和体细胞评分4个指标影响达到极显著水平(P＜0.01),临床乳房炎和隐性乳房炎奶牛日产奶量和乳糖含量极显著低于正常奶,同时体细胞数和体细胞评分极显著高于正常奶,而临床乳房炎奶和隐性乳房炎奶在所有检测指标上均无显著差异,但临床乳房炎奶比隐性乳房炎奶体细胞数高出约100万·mL-1.不同病原菌组成类型对乳中体细胞数和体细胞评分有极显著影响(P＜0.01),而对其它性状无显著影响(P＞0.05).混合感染奶牛测定日产奶量极显著低于单独感染奶牛(P＜0.01),同时乳中体细胞数显著高于单独感染奶牛(P＜0.01).乳房炎类型对乳中SCC的变化趋势有显著影响(P＜0.01),正常奶牛维持较低SCC的能力较强,隐性乳房炎奶牛在下一泌乳月体细胞增加的可能性较大.不同隐性乳房炎病原菌组成类型对乳中SCC的变化无显著影响.奶牛生产中隐性乳房炎发病率高,危害性也最大,不同病原菌混合感染引起的隐性乳房炎对测定日产奶量和乳中体细胞数影响最大.该结果为奶牛场采取合理措施,降低隐性乳房炎发生率提供了参考.     

硫酸头孢喹肟乳房（干乳期）注入剂在奶牛乳汁中的残留消除研究

建立了牛奶中硫酸头孢喹肟残留超高效液相色谱-串联质谱检测方法(UPLC-MS/MS)。选取18头刚进入干乳期的健康奶牛,随机分为6个组,分别于预产期前的42、35、28、21、14和7 d进行乳房注入硫酸头孢喹肟乳房注入剂(3 g∶150 mg/支),只用药一次,产犊后采集奶样。结果表明:预产期前7 d给药,奶牛产犊72 h后采集的奶样中头孢喹肟残留量降至MRL(20μg/kg)附近;预产期前14 d和21 d给药,奶牛产犊12 h后采集的奶样中头孢喹肟残留量降至MRL以下,均低于检测限;预产期前28、35和42 d给药,所有采集奶样的头孢喹肟残留量均低于检测限。建议在预产期前7、14和21 d给药硫酸头孢喹肟乳房注入剂的弃奶期分别为产犊后5、1和0 d。     

酶菌复合制剂对奶牛生产性能和体细胞数的影响

本试验旨在研究酶菌复合制剂对奶牛生产性能和体细胞数的影响。选取年龄、胎次、泌乳天数及生理性状相近的荷斯坦奶牛240头,随机为成4组,每组6个重复,每个重复10头牛。对照组饲喂基础日粮,试验Ⅰ、Ⅱ和Ⅲ组分别在基础日粮中添加0.5、1.0和1.5 kg/t的酶菌复合制剂,预试期10 d,正试期40 d,分别于试验第10、20、30、40天采集牛粪便,利用粪便分析筛对牛粪便组成进行分析。分别在试验第1、20、40天采集乳样,采用乳汁分析仪测定各组乳样中乳脂率、乳蛋白率、非脂固形物和奶中体细胞数（SCC）,试验期间记录每头牛平均日产奶量（ADMY）及平均日采食量（ADFI）。试验结果表明,添加酶菌复合制剂能够显著增加奶牛平均日产奶量（P<0.05）,提高牛乳中乳蛋白和乳脂肪含量（P<0.05）,降低体细胞数（P<0.05）,改善粪便结构。综合试验结果,酶菌复合制剂应用于奶牛养殖的最优添加量为1.0 kg/t,可以提高奶牛产奶量,降低牛体细胞数。     

乳房炎疫苗对奶牛体细胞数及隐性乳房炎的影响研究

乳房炎是奶牛最主要的疾病之一,每年都会给奶牛业带来巨额的经济损失。针对不同的病原菌,所采取的防控措施也有所不同。本研究引入经欧盟EMA认证的乳房炎大肠杆菌和葡萄球菌二联灭活疫苗,在国内两个奶牛场进行临床测试,验证其临床使用效果。选择地处西安和白银的两个规模化奶牛场,根据奶牛进入干奶期前的奶样检测结果、产量、体况评分等指标,筛选出240头奶牛入选临床测试,按照免疫程序进行免疫后,在产犊后的第2周、第6周、第10周、第14周和第18周分别采奶样检测体细胞数,并对奶样中的细菌进行分离鉴定,确定该疫苗对隐性乳房炎发病状况以及奶牛体细胞数的影响。结果显示,疫苗表现出了优异的效果,特别是第14周,免疫组奶牛的保护率远高于对照组,差异显著(P0.05),其他阶段免疫组的保护率也均高于对照组。两个奶牛场在干奶前1周免疫组的体细胞数和对照组几乎相近,而进入泌乳期后免疫组的体细胞数持续低于对照组,说明试验牛在免疫疫苗后,抗体对病原菌产生了积极作用,缓解了炎症反应,降低了乳中体细胞数。这也从另一方面说明该疫苗具有提高奶牛机体对抗特异性病原的作用。     

乳房炎对奶牛产奶量的影响

为了研究乳房炎对奶牛产奶量的影响,收集了西安某奶牛场的620头荷斯坦奶牛完整记录的全年报告中体细胞数据、生产性能和兽医记录,对比分析不同体细胞数对奶牛胎次奶量﹑日产奶量的影响;结果表明,临床乳房炎极显著降低奶牛305d奶量,而在泌乳盛期患病的牛305d奶量减低可达32.5%。隐性乳房炎对奶牛产奶量的影响随患病程度加重而增大。平均体细胞数20万/mL,胎次奶量就会显著较少,而体细胞数50万/mL,胎次奶量极显著降低。奶牛泌乳盛期患隐性乳房炎比泌乳中后期患隐性乳房炎对产奶量影响更大。     

复方阿莫西林乳房注入剂对临床型奶牛乳房炎的治疗效果

为评价复方阿莫西林乳房注入剂对泌乳期奶牛临床型乳房炎的治疗效果,在甘肃某两个牛场选择70头自然发生的临床型乳房炎奶牛进行临床试验。将患病奶牛随机分为试验组(n=36头)和对照组(n=34头)。试验用药和对照用药分别为郑州百瑞动物药业有限公司和齐鲁动物保健品有限公司提供的复方阿莫西林乳房注入剂。每个感染乳区注入3 g药物,每12 h注射1次,连续用药3 d。在用药前、停药后7 d及14 d采集各组奶牛的奶样进行细菌学检测及乳汁体细胞计数。通过临床观察、细菌清除率及体细胞计数变化对临床疗效进行评价。停药后14 d,试验组和对照组的临床治愈率分别为58.3%和61.8%,细菌总清除率分别为94.12%和93.55%。两组奶样中的SCC在治疗后均显著下降(P<0.01)。两组临床疗效无统计学差异(P>0.05),表明试验用药对奶牛临床型乳房炎具有良好的治疗效果。     

Safety Study on Cefquinome Sulfate Intrauterine Infusion for Lactating Cows

The aim of this experiment was to study the safety of cefquinome sulfate intrauterine infusion for lactating cows.24 healthy lactating Chinese Holstein cows were randomly divided into four groups(6 cows in each group).Cows in groups Ⅰ, Ⅱ and Ⅲ were respectively injected different doses of cefquinome sulfate intrauterine infusion in uterus, and cows in the blank control group(group Ⅳ) were injected the dose of sterilized saline water.The cows were injected with the tested drug in uterus for twice and the interval was 72 h.The indicators including body temperature(rectal temperature), pulse rate, respiratory rate, blood physiological and biochemical indexes, mental state, daily milk yield and somatic cell count(SCC) in milk were respectively observed and measured on the day of first administration, the day of final administration and the 7th day after final administration.The results showed that injecting lactating cows cefquinome sulfate intrauterine infusion to lactating cows as recommended dosage was safe.The drug could be used to treat endometritis of lactating cows in clinical practice.     

奶牛临床型乳房炎Nisin抗菌肽治疗后日产奶量及主要乳成分的变化

选取临床型乳房炎自然发病病例9头,乳房内灌注乳酸链球菌素(Nisin)进行治疗,通过检测日产奶量以及停药后2,7,14,21 d的主要乳成分指标,确定Nisin乳房灌注剂对临床型乳房炎病例泌乳性能的影响情况。结果显示,乳房内灌注Nisin后患病乳区乳腺组织得到一定程度的修复,日产奶量逐渐恢复,停药后8 d的日产奶量与发病前6 d相比,平均降幅2.5 kg。治愈后患病乳区牛奶乳脂肪、乳蛋白、乳糖和非脂乳固体含量都呈现上升趋势,但与同期相比,略低于非用药乳区混合牛奶;其中,乳糖含量增加幅度较快,除停药后2 d的治疗乳区外,乳糖含量均在4.7%以上,提示奶牛乳房炎病例经Nisin乳房灌注治疗后,受损乳腺组织修复较快,乳腺上皮细胞合成乳成分的能力大幅度提高。由此可见,Nisin对奶牛临床型乳房炎具有良好的治疗作用。     

Effects of two anti-inflammatory drugs on physiologic variables and milk production in cows with endotoxin-induced mastitis

OBJECTIVE: To determine the effects of 2 anti-inflammatory drugs in lactating Holstein cows with endotoxin-induced mastitis. ANIMALS: 30 multiparous Holstein cows that had been lactating for 30 to 60 days. PROCEDURE: Bacterial culture of milk samples and physical examinations established that study cows were in good health and free of mastitis. Mastitis was induced in 1 front mammary gland by intramammary administration of purified bacterial endotoxin. Cows were allocated into 1 of 3 treatment groups: untreated endotoxic mastitis (n = 9), endotoxic mastitis plus flunixin meglumine (9), and endotoxic mastitis plus isoflupredone acetate (10). Heart rate, rectal temperature, mammary surface area, and rumen motility were recorded hourly for 14 hours following endotoxin administration. Flunixin meglumine or isoflupredone acetate was administered after mammary swelling and rectal temperature > or = 40 degrees C had developed. Milk production was evaluated from 5 days before to 10 days after induction of mastitis. RESULTS: Neither drug ameliorated loss of milk production or swelling of the affected mammary gland. Both drugs reduced mean heart rate during the 14 hours following endotoxin administration, compared with untreated control cows. Cows treated with flunixin meglumine had increased rumen motility and decreased rectal temperature during the same period, compared with all other cows. CONCLUSIONS AND CLINICAL RELEVANCE: Neither drug enhanced recovery of milk production following endotoxin-induced mastitis. Flunixin meglumine decreased rectal temperature, whereas isoflupredone did not; however, it has not been established that reduction of fever is beneficial to cows with naturally occurring mastitis.     

Anti-inflammatory effects of intramammary infusions of glycyrrhizin in lactating cows with mastitis caused by coagulase-negative staphylococci

OBJECTIVE: To determine the anti-inflammatory effects of glycyrrhizin (GL) in lactating cows with mastitis attributable to naturally occurring infection with coagulase-negative staphylococci (CNS). ANIMALS: 12 lactating Holstein cows with mastitis attributable to infection with CNS and 2 healthy cows without mastitis. PROCEDURE: Clinical signs, number of bacteria in milk, somatic cell count (SCC) in milk, concentrations of alpha-lactalbumin and lactoferrin in milk, and concentration of histamine in milk were investigated before and after intramammary infusion of GL (6 cows) or antimicrobials (6 cows). Glands of 2 healthy cows were infused with staphylococcal enterotoxin; milk leukocytes were then harvested and incubated with various doses of GL. RESULTS: In cows infected with CNS that had a low bacterial concentration in milk, infusion of GL alone resulted in significant improvements in swelling, firmness of glands, and number of clots in milk, and it decreased the SCC, but not significantly. Percentage of neutrophils decreased significantly (to < 30%) by 2 days after infusion. Use of lactoferrin as a marker of inflammation in mammary glands revealed a decrease in concentrations, whereas use of alpha-lactalbumin as a marker of recovery for mammary glands revealed significant increases in concentrations in the GL-infused group. Accompanying these anti-inflammatory effects, a decrease in the concentration of histamine in milk was observed in the GL-infused group. Glycyrrhizin decreased histamine production by milk leukocytes in a concentration-dependent manner. CONCLUSIONS AND CLINICAL RELEVANCE: Infusion of GL may regulate intramammary inflammation through modulation of inflammatory mediators such as histamine.     

Effect of intramammary infusion of rbGM-CSF on SCC and expression of polymorphonuclear neutrophil adhesion molecules in subclinical mastitis cows

The effect of rbGM-CSF intramammary infusion on the subclinical mastitis was evaluated by the somatic cell count (SCC) and expression of adhesion molecules (CD62L and CD11b) on the surface of neutrophils (PMN) in blood and milk. Fifteen cows diagnosed to have subclinical mastitis were used in this study. Seven cows showed a decrease in the SCC (decreased group), whereas 8 cows showed an increase in the SCC (increased group) 7 days after infusion of rbGM-CSF compared to pre infusion level. The percentage of CD62+ cells tended to be lower and CD11b+cells tended to be higher at 6 h on blood PMN in the decreased group of cows. Increased group of cows showed opposite tendencies. The mean fluorescent intensity of these adhesion molecules expressed on PMN in blood and milk was similar in both groups. These results suggested some association between expression of adhesion molecules and changes in SCC by rbGM-CSF. Responsiveness of PMN adhesion molecules to rbGM-CSF might determine the changes in SCC of the subclinical mastitic cows after infusion of rbGM-CSF.     

Somatic cell count in milk of selenium-supplemented dairy cows after an intramammary challenge with Staphylococcus aureus

The objective of this study was to evaluate the effect of selenium (Se) supplementation on milk somatic cell count (SCC) in dairy cows. Twelve multiparous Holstein-Friesian cows were fed a diet containing a suboptimal Se concentration (<0.05 ppm, dry basis) starting 2 months before calving. Supplemented cows (n=6) received a single s.c. injection of barium selenate (1 ml/50 kg BW) 45 days prior to calving, whereas control group was kept unsupplemented. Twenty weeks after calving, two mammary quarters (right side) of each cow were challenged with 205,000 cfu/ml of Staphylococcus aureus (strain Newbould 305). Blood was collected bi-weekly until day 150 of lactation for the analysis of blood glutathione peroxidase (GPx1; EC 1.11.1.9) activity. To re-isolate the challenging pathogen and to evaluate SCC, aseptic milk samples were collected daily starting on the day of challenge, and finishing 7 days after inoculation. Unsupplemented cows had a lower activity of GPx1 through the experiment (P<0.001). Natural log SCC (lnSCC) was higher in unsupplemented than Se-supplemented cows (P=0.04), showing evidence of significance after 5 days. Selenium supplementation of dairy cows fed a diet containing a suboptimal Se concentration, resulted in higher blood activity of GPx1, and lower mean lnSCC after an intramammary challenge with Staph. aureus.     

Persistent Experimental Salmonella dublin Intramammary Infection in Dairy Cows

Experimental intramammary infections were induced in five post-parturient Holstein cows by inoculation of low numbers (5000 colony forming units) of virulent Salmonella dublin via the teat canal of mammary gland quarters. Rectal temperature, pulse and respiratory rates, milk yield, and milk quality as assessed by the California Mastitis Test (CMT) and somatic cell counts (SCC) were recorded every 12 hours at milking. Bacteriologic cultures of foremilk quarter samples and feces were obtained daily, as were complete blood counts. ELISA titers for IgG and IgM recognizing S. dublin lipopolysaccharide (LPS) were obtained weekly on serum and quarter milk samples. All cows excreted S. dublin intermittently from infected quarters, but no changes were detected in rectal temperature, appearance of the mammary gland or secretions, CBC, milk yield, and pulse and respiratory rates. Somatic cell counts were modestly increased in infected quarters as compared with uninfected quarters (P = .015, paired t test); however, CMT scores after infection remained low, and were not significantly different from pre-infection scores (P greater than .10, sign test). After infection, administration of dexamethasone resulted in signs of clinical mastitis and increased excretion of S. dublin from mammary quarters (P = .0004, paired t test). One cow had necrotizing mastitis and S. dublin septicemia and was euthanatized. In the four surviving cows, clinical improvement was observed after systemic gentamicin therapy and intramammary infusion with polymyxin B, but all cows continued to excrete S. dublin intermittently from one or more quarters and occasionally from feces for the remaining period of observation. All infected cows demonstrated a rise in IgG and IgM ELISA titers recognizing S. dublin LPS in serum and milk. At necropsy (13-25 weeks postinfection), S. dublin was recovered only from the mammary tissue or supramammary lymph nodes in three of four cows. In one cow, mammary gland and lymph-node samples were negative for S. dublin despite positive milk cultures. In all cows, histopathologic examination revealed multifocal areas of chronic active mastitis. These lesions were similar to histopathologic findings from mammary gland carriers with naturally acquired S. dublin infection.     

Variation of inflammatory dynamics and mediators in primiparous cows after intramammary challenge with Escherichia coli

ABSTRACT: The objective of the current study was to investigate (i) the outcome of experimentally induced Escherichia coli mastitis in primiparous cows during early lactation in relation with production of eicosanoids and inflammatory indicators, and (ii) the validity of thermography to evaluate temperature changes on udder skin surface after experimentally induced E. coli mastitis. Nine primiparous Holstein Friesian cows were inoculated 24 ± 6 days (d) after parturition in both left quarters with E. coli P4 serotype O32:H37. Blood and milk samples were collected before and after challenge with E. coli. The infrared images were taken from the caudal view of the udder following challenge with E. coli. No relationship was detected between severity of mastitis and changes of thromboxane B2 (TXB2), leukotriene B4 (LTB4) and lipoxin A4 (LXA4). However, prostaglandin E2 (PGE2) was related to systemic disease severity during E. coli mastitis. Moreover, reduced somatic cell count (SCC), fewer circulating basophils, increased concentration of tumor necrosis factor-α (TNF-α) and higher milk sodium and lower milk potassium concentrations were related to systemic disease severity. The thermal camera was capable of detecting 2-3°C temperature changes on udder skin surface of cows inoculated with E. coli. Peak of udder skin temperature occurred after peak of rectal temperature and appearance of local signs of induced E. coli mastitis. Although infrared thermography was a successful method for detecting the changes in udder skin surface temperature following intramammary challenge with E. coli, it did not show to be a promising tool for early detection of mastitis.