呼和浩特地区奶牛乳房炎病原菌分离鉴定及其致病性与药敏试验

对呼市地区部分奶牛场64头奶牛的256份乳样随机取样64份进行细菌分离鉴定,并选择主要致病菌进行动物致病性试验和药物敏感性试验。引起本地区奶牛乳房炎的主要致病菌为停乳链球菌、金黄色葡萄球菌、大肠杆菌、克雷伯氏菌等,多数引起奶牛乳房炎的病原菌的致病力不强,但这些细菌在乳房内繁殖和产生的毒素、代谢产物等可造成乳房出现炎症,各养殖场分离菌对试验中所使用抗菌药物的敏感性差异极大。     

奶牛乳房炎的诱因及防治

奶牛乳房炎是威胁养牛业的主要疾病之一。为有效地防治不同类型的乳房炎,需了解不同乳房炎病原菌的传播途径、传染性及其对抗菌治疗的反应。1奶牛乳房炎的诱因1.1无乳链球菌(或称乏乳链球菌)无乳链球菌是最常见的乳房细菌之一,具有很高的传染性。它几乎是乳腺的专门寄生菌,很少感染其他组织,主要通过挤奶员的手、挤奶用具以及机械榨奶时器械消毒不完全等使该细菌得到传播,牛舍内的蝇类也可成为传播媒介。无乳链球菌附着在乳腺管壁上,使乳腺受到破坏,引起慢性乳房炎,影响乳腺正常泌乳,使奶牛的产奶量下降。1.2金黄色葡萄球菌金黄色葡萄球菌也…     

奶牛乳房炎主要致病菌的分离与鉴定及体外抑菌试验

引起奶牛乳房炎的主要致病菌为金黄色葡萄球菌、停乳链球菌、无乳链球菌和大肠杆菌[1].对于乳房炎的治疗,一般都是采用抗生素等药物,但随着抗生素长期大剂量的广泛使用,细菌抗药性和抗生素乳中残留问题被普遍关注.     

奶牛乳房炎主要致病茵的分离与鉴定及体外抑菌试验

引起奶牛乳房炎的主要致病菌为金黄色葡萄球菌、停乳链球菌、无乳链球菌和大肠杆菌。对于乳房炎的治疗，一般都是采用抗生素等药物，但随着抗生素长期大剂量的广泛使用，细菌抗药性和抗生素乳中残留问题被普遍关注。中草药是纯天然物质，具有抗菌、消炎、细菌不易产生耐药性、低毒等特点，具有抗生素无法比拟的优点。所以应用中草药替代抗生素防治奶牛乳腺炎，已日益为国内外学者所关注。     

自拟中草药复方对奶牛乳房炎致病菌体外抑菌试验

奶牛乳房炎是危害奶牛养殖业最常见的疾病，引起奶牛乳房炎的病原菌很多，主要致病菌为金黄色葡萄球菌、表皮葡萄球菌、停乳链球菌、无乳停乳链球菌和大肠杆菌等。应用抗菌药物治疗乳房炎是国内外普遍采用的主要措施之一，但随着抗菌剂长期大剂量的广泛使用，细菌耐药性和抗菌药物乳中残留问题被普遍关注。中药作为天然药物，不仅不存在药物残留带来的公共卫生问题，而且许多中药还是很好的免疫调节剂，因此，用中药治疗奶牛乳房炎的研究成为近年来的热门课题。一些中药复方制剂和中药提取物制剂，已经在奶牛乳房炎的防治方面发挥了重要作用。     

奶牛隐性乳房炎病原的药敏试验及治疗措施

奶牛隐性乳房炎是奶牛的一种多发病,此病症会对奶牛养殖业造成重大的损失。采集某奶牛场的隐性乳房炎奶牛乳样进行药敏试验,结果表明,金黄色葡萄球菌、乳房链球菌及无乳链球菌等细菌是主要的病原菌;致病菌对庆大霉素、磷霉素、西索米星和环丙沙星等敏感。笔者将试验结果与奶牛疾病防治现状相结合,制定出针对奶牛隐性乳房炎的治疗措施,以降低因奶牛隐性乳房炎造成的奶牛场经济损失。     

奶牛隐性乳房炎病原菌的分离鉴定

为了解河北省昌黎县某奶牛场荷斯坦奶牛隐性乳房炎的主要致病菌,随机无菌采集29头奶牛乳样,做细菌分离培养,37℃培养24 h后观察细菌生长状况,对细菌经革兰染色镜检、生化试验等实验室检查,确定引起该牛场引发隐性乳房炎的致病菌。结果表明,葡萄球菌为50.54%,链球菌为20.87%,杆菌为28.57%,认为葡萄球菌是引发该牛场隐性乳房炎的主要致病菌,且以金黄色葡萄球菌为主。     

中国奶牛乳房炎致病菌地域分布及时间变化

为进一步了解奶牛乳房炎致病菌的菌群分布以及时间变化。使用中国知网(CNKI)数据库检索奶牛乳房炎、病原菌分离,将检索得到的论文数据进行整理;根据气候等因素将中国地域划分为三大区域:西北、北方、南方,比较三大地域之间奶牛乳房炎致病菌的种类多寡、所占比重、主要致病菌的差异以及主要致病菌随时间的变动趋势。结果显示:西北地区所分离得到的奶牛乳房炎致病菌种类最为丰富,共计22种;北方与南方致病菌种类均为16种;三大地域分离得到的主要致病菌为:金黄色葡萄球菌、凝固酶阴性葡萄球菌(CNS)、无乳链球菌、停乳链球菌、乳房链球菌、大肠杆菌、沙门菌、克雷伯菌,这8种致病菌进行地域间差异性比较分析发现,三大地域间奶牛乳房炎主要致病菌分离率无显著差异,规模化养殖淡化了气候对致病菌差异的影响,不同地域奶牛养殖过程中应对几类主要致病菌进行无差别防治;在时间变化上,金黄色葡萄球菌与大肠杆菌呈先上升后下降的趋势,CNS和无乳链球菌呈上升趋势,而停乳链球菌与乳房链球菌则呈下降趋势。提示在奶牛养殖生产过程中应注重对CNS及无乳链球菌的防范。     

通用基因芯片对奶牛乳房炎主要致病茵的检测

应用生物信息学手段和查阅文献资料设计了金黄色葡萄球菌、大肠埃希菌、无乳链球菌、绿脓杆菌、停乳链球菌、乳房链球菌6种奶牛乳房炎主要致病菌的通用引物和金黄色葡萄球菌、大肠埃希菌、绿脓杆菌的寡核苷酸探针及无乳链球菌、停乳链球菌、乳房链球菌的特异引物,并用这3种特异引物扩增片段的纯化产物作为这3种链球菌的检测探针。在引物对样品中细菌的相应基因片段扩增的同时进行靶基因的生物素标记,扩增的产物与硝酸纤维素膜上的探针进行杂交,酶联、显色后根据芯片扫描仪的判读结果来确定奶牛乳房炎致病菌感染的种类。结果表明,建立的以16S rDNA为对象的基因芯片技术可以快速的检测出以上6种细菌,整个检测过程需要6h~7h,灵敏度高,特异性好,能快速的对奶牛乳房炎的主要致病菌做出诊断。     

通用基因芯片对奶牛乳房炎主要致病菌的检测

应用生物信息学手段和查阅文献资料设计了金黄色葡萄球菌、大肠埃希菌、无乳链球菌、绿脓杆菌、停乳链球菌、乳房链球菌6种奶牛乳房炎主要致病菌的通用引物和金黄色葡萄球菌、大肠埃希菌、绿脓杆菌的寡核苷酸探针及无乳链球菌、停乳链球菌、乳房链球菌的特异引物,并用这3种特异引物扩增片段的纯化产物作为这3种链球菌的检测探针。在引物对样品中细菌的相应基因片段扩增的同时进行靶基因的生物素标记,扩增的产物与硝酸纤维素膜上的探针进行杂交,酶联、显色后根据芯片扫描仪的判读结果来确定奶牛乳房炎致病菌感染的种类。结果表明,建立的以16S rDNA为对象的基因芯片技术可以快速的检测出以上6种细菌,整个检测过程需要6h-7h,灵敏度高,特异性好,能快速的对奶牛乳房炎的主要致病菌做出诊断。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -