鸡肠气泡病一例

肠气泡病为肠壁囊状气肿,也叫肠气肿,是气体充满气泡发生在肠粘膜、粘膜下、浆膜和肠系膜淋巴结的一种疾病。这种病过去很少见,现就接受的送检病料中鸡肠气泡病一例的病理变化报告如下:1981年1月15日长春市郊区某鸡场     

微生态制剂防治奶牛子宫内膜炎研究进展

子宫内膜炎是奶牛产后多发病,屡配不孕的奶牛中患子宫内膜炎的占1/2以上。患病牛由于子宫存在炎症,无法完成受孕过程,给我国乃至世界奶牛业造成严重经济损失。由于抗生素的大量应用,病原菌的抗菌谱越来越广,耐药问题日趋严重,开发抗生素替代疗法得到学界广泛共识。微生态制剂具有绿色、安全、无残留等特点,是最有潜力的抗生素替代品之一。本文主要阐述奶牛子宫内膜炎的发病机理,微生态制剂的种类、应用,以及微生态制剂防控奶牛子宫内膜炎作用机理,以期为抗生素减量化防治奶牛子宫内膜炎的研究提供参考。     

竖直矩形通道内空气-水两相流动中气泡聚合研究

本文在自然循环条件下,研究竖直上升矩形通道(50×50mm2)内气泡聚合行为特性,在此基础上进一步分析气泡聚合对自然循环能力的影响。结果表明:本实验条件下气泡初始平均直径大于4.5mm时升力系数大于零,直径小于4.5mm时升力系数变为负值;两气泡平均间距大于8.3mm时,几乎不能看到聚合过程;实验范围内,自然循环水流量是随着气体流量的增加而增大,在气体流量小于1.30kg/h,增大气流量对提升自然循环能力的效果较气流量大于1.30kg/h更好。     

北方农牧交错区奶牛场舍内外有害气体的季节性变化

本试验旨在探究北方农牧交错区牛舍内外有害气体的变化规律,为有效控制奶牛舍有害气体提供理论依据。试验选择内蒙古西部农牧交错区某奶牛场作为研究对象,在一年中四个季节测定牛舍内外的有害气体含量,每季节连续测定三天。结果表明,舍内外有害气体有一定的季节性变化规律;舍内有害气体含量明显高于舍外,但均未超标。     

动物微生态制剂在反刍动物养殖中的最新应用研究

动物微生态制剂作为一种新型无毒、无污染生物制品类饲料添加剂,在调节动物机体微生态平衡、预防疾病、提高饲料转化率、促进动物健康和保护生态环境等方面有着其它添加剂不可替代的作用,而且随着作用机理以及生产工艺研究的深入和效果的进一步凸显,应用也会越来越广泛.文章就近年来动物微生态制剂在反刍动物养殖方面的制剂种类、作用机理、作用效果及应用前景进行综述.     

动物微生态制剂在养猪生产中的应用研究

动物微生态制剂作为一种新型的无毒、无污染生物制品类饲料添加剂,在调节动物机体微生态平衡、预防疾病、提高饲料转化率、促进动物健康和保护生态环境等方面有着其他添加剂不可替代的作用,而且随着作用机理研究的深入,效果的进一步凸显,应用也越来越广泛.笔者就近年来动物微生态制剂在养猪生产中的制剂种类、作用机理、作用效果及应用前景进行了综述.     

微生态制剂在水产养殖中的作用机理及应用研究进展

介绍了微生态制剂在水产动物健康养殖中的作用机制,以及微生态制剂在刺参养殖中的应用前景。微生态制剂在水产动物中的作用机理包括通过竞争来抑制病原菌生长（如黏附位点、营养、能源等）、通过代谢物（如抑菌物质、消化酶等）调节微生态平衡、提高免疫机能、改善水质、群体感应（quorum sensing,QS）。刺参生理生化反应、生活习性的研究为刺参微生态制剂的开发奠定了基础,也存在一些问题限制了它在刺参养殖中的应用,但微生态制剂仍然是抗生素最有潜力的替代品,具有广阔的应用前景。     

饲用复合酶制剂的机理与应用

饲用复合酶制剂的机理与应用江苏省吴县太湖酶制剂厂一、饲用复合酶机理的研究动物饲料９０％以上由各种植物种子组成，植物种子有一个极其复杂的结构，它是由各类三维组合构成，由三维组合部分既是营养成分的保护层，又是其贮藏处。显示了玉米粒内所含的大量细胞，同时也...     

鹌鹑球虫病并发皮下气肿的诊治

鹌鹑球虫病是危害幼鹑的一种急性传染性原虫病,患病鹌鹑呆立、下痢.本病以2～10周龄的鹌鹑最易感,若治疗不及时,病鹑的死亡率将增加.皮下气肿一般因鹌鹑剧烈活动使气囊破裂,气囊内的气体逸出至皮下所致,一般皮下气肿的致死率极低. 1发病情况 某鹌鹑养殖场饲养的16日龄的鹌鹑突然发病,病鹑食欲减退或废绝,个别鹌鹑头部或身体前部的皮下有气体,病鹑所排粪便呈黄褐色或灰黄色,重症病例很快昏迷、死亡.用药物治疗7d后病鹑死亡率下降,其精神状态、食欲、饮欲等有所恢复,但仍有皮下气肿病例出现,并有个别病例死亡.减小饲养密度后皮下气肿病例未再出现,也未出现死亡.     

达力朗治疗母牛胎衣不下

牛胎衣不下是临床常见疾病,奶牛场正常患病率为5%～10%,有的高达22%左右,笔者在综合牧场奶牛场工作多年,经采用达力朗治疗牛胎衣不下150多头,获效很满意。1　达力朗的作用机理　达力朗是法国进口子宫塞剂胶囊,是专门防治家畜阴道疾病的最新处方药剂。其中碘仿是有效的强力杀菌剂,且亦有ｉｏｄｉｎｅ快速诱菌及愈合的药效。麝香草是加利树提炼的强力杀菌剂。乙醚是另一有效的麻醉止痛剂。达力朗为油性制剂,能保证有效成分在阴道子宫内药效扩散性强又具持久性,长时间停留在生殖道粘膜上,效果比水剂好。2　典型病例　病例1:某奶牛场1头中国荷斯…     

贵州火龙果溃疡病发生情况及发病因素调查

溃疡病是火龙果种植上的重要病害。为掌握火龙果溃疡病在贵州火龙果主产区的发生情况和发病因素,为田间防控提供科学依据,特开展此调查研究。结果表明：罗甸、镇宁、关岭、望谟及贞丰5个主产县火龙果溃疡病均有不同程度发生,且主栽品种均可发病,各树龄果园均可发病。病害在冬季发生不明显,3月气温回升后病害开始陆续发生和扩展,4月上旬（清明前后）雨水较多病情迅速增长,是春季防控的关键时期。5~7月进入雨季,田间高温高湿,为病害大面积蔓延流行期,需及时做好田间防控,以保证火龙果安全生产。     

猪不同生长阶段肠道微生物组的变化及其影响因素

肠道是机体重要的消化与免疫器官,维持肠道健康对猪的生长发育和疾病预防具有十分重要的意义。高通量测序技术的发展极大地促进了人们对肠道微生物功能的认知,猪肠道微生物组的研究正逐步成为热点。目前,尽管对某一生长阶段猪的肠道微生物组已有较为深入的理解,但仍缺乏有关商品猪整个生命周期范围内肠道微生物组动态变化的全面纵向研究。而从出生到出栏,猪在整个生长周期内的肠道微生物组并不是一成不变的,是一个动态的发育过程。作者综述了猪哺乳期、断奶期、育肥期和妊娠期等从出生到育肥过程中不同阶段肠道微生物组的纵向变化及其主要影响因素：一方面,肠道微生物群落结构的显著变化主要发生在断奶期;另一方面,虽然肠道微生物组成随着时间始终在不断变化,但仍有一部分优势菌是一直存在的,这部分优势菌被称为核心菌群,而只在特定时期才出现的菌只是胃肠道中的"过客",也最易受外界因素影响。肠道微生物组与多种因素相关,如年龄、饮食、环境、抗生素使用等,其中饮食对塑造肠道微生物起到至关重要的作用。本文可为理解猪在不同生长发育阶段肠道微生物的动态变化规律及改善猪生长性能和健康水平的微生物技术手段提供理论参考。     

Will Culling White‐Tailed Deer Prevent Lyme Disease?

White‐tailed deer play an important role in the ecology of Lyme disease. In the United States, where the incidence and geographic range of Lyme disease continue to increase, reduction of white‐tailed deer populations has been proposed as a means of preventing human illness. The effectiveness of this politically sensitive prevention method is poorly understood. We summarize and evaluate available evidence regarding the effect of deer reduction on vector tick abundance and human disease incidence. Elimination of deer from islands and other isolated settings can have a substantial impact on the reproduction of blacklegged ticks, while reduction short of complete elimination has yielded mixed results. To date, most studies have been conducted in ecologic situations that are not representative to the vast majority of areas with high human Lyme disease risk. Robust evidence linking deer control to reduced human Lyme disease risk is lacking. Currently, there is insufficient evidence to recommend deer population reduction as a Lyme disease prevention measure, except in specific ecologic circumstances.     

牦牛泰勒虫病的诊治体会

牦牛是生活在高海拔地区的一种特殊动物,具有耐寒、耐粗饲、适应性、抗病力强等特点,兽医临床上牦牛患病率低,尤其是随着牧民科学文化素质的提高,预防性驱虫、免疫注射等动物疫病防控措施在牧区得到有效落实,加上牦牛生活的环境因素,牦牛泰勒虫病感染率极低。但随着养殖规模的不断扩大,蜱虫大量寄生,造成草场污染,牧区牦牛泰勒虫病偶有发生。笔者采用灭蜱、杀虫、强心、补液、保肝利胆等综合治疗方法,效果较好。     

Canine parvovirus in Australia: The role of socio-economic factors in disease clusters

To identify clusters of canine parvoviral related disease occurring in Australia during 2010 and investigate the role of socio-economic factors contributing to these clusters, reported cases of canine parvovirus were extracted from an on-line disease surveillance system. Reported residential postcode was used to locate cases, and clusters were identified using a scan statistic. Cases included in clusters were compared to those not included in such clusters with respect to human socioeconomic factors (postcode area relative socioeconomic disadvantage, economic resources, education and occupation) and dog factors (neuter status, breed, age, gender, vaccination status). During 2010, there were 1187 cases of canine parvovirus reported. Nineteen significant (P<0.05) disease clusters were identified, most commonly located in New South Wales. Eleven (58%) clusters occurred between April and July, and the average cluster length was 5.7days. All clusters occurred in postcodes with a significantly (P<0.05) greater level of relative socioeconomic disadvantage and a lower rank in education and occupation, and it was noted that clustered cases were less likely to have been neutered (P=0.004). No significant difference (P>0.05) was found between cases reported from cluster postcodes and those not within clusters for dog age, gender, breed or vaccination status (although the latter needs to be interpreted with caution, since vaccination was absent in most of the cases). Further research is required to investigate the apparent association between indicators of poor socioeconomic status and clusters of reported canine parvovirus diseases; however these initial findings may be useful for developing geographically- and temporally-targeted prevention and disease control programs.     

Equine coronavirus: An emerging enteric virus of adult horses

Equine coronavirus (ECoV) is an emerging virus associated clinically and epidemiologically with fever, depression, anorexia and less frequently colic and diarrhoea in adult horses. Sporadic cases and outbreaks have been reported with increased frequency since 2010 from Japan, the USA and more recently from Europe. A faeco‐oral transmission route is suspected and clinical or asymptomatic infected horses appear to be responsible for direct and indirect transmission of ECoV. A presumptive clinical diagnosis of ECoV infection may be suggested by clinical presentation, haematological abnormalities such as leucopenia due to lymphopenia and/or neutropenia. Confirmation of ECoV infection is provided by specific ECoV nucleic acid detection in faeces by quantitative PCR (qPCR) or demonstration of coronavirus antigen by immunohistochemistry or electron microscopy in intestinal biopsy material obtained ante or post mortem. The disease is generally self‐limiting and horses typically recover with symptomatic supportive care. Complications associated with disruption of the gastrointestinal barrier have been reported in some infected horses and include endotoxaemia, septicaemia and hyperammonaemia‐associated encephalopathy. Although specific immunoprophylactic measures have been shown to be effective in disease prevention for closely‐related coronaviruses such as bovine coronavirus (BCoV), such strategies have yet not been investigated for horses and disease prevention is limited to basic biosecurity protocols. This article reviews current knowledge concerning the aetiology, epidemiology, clinical signs, diagnosis, pathology, treatment and prevention of ECoV infection in adult horses.     

Emerging zoonoses: the challenge for public health and biodefense

The concept of new and emerging diseases has captured the public interest and has revitalized the public health infectious disease research community. This interest has also resulted in competition for funding and turf wars between animal health and public health scientists and public officials and, in some cases, has delayed and hindered progress toward effective prevention, control and biodefense. There is a dynamic list of outbreaks causing substantial morbidity and mortality in humans and often in the reservoir animal species. Some agents have the potential to grow into major epidemics. There are many determinants that influence the emergence of diseases of concern that require the use of current understanding of the nature of agent persistence and spread. Additional factors that are global must be added to plans for prevention and control. To this complex mix has been added the potential for accidental or malicious release of agents. The nature of emerging infectious agents and their impact is largely unpredictable. Models that strive to predict the dynamics of agents may be useful but can also blind us to increasing disease risks if it does not match a specific model. Field investigations of early events will be critical and should drive prevention and control actions. Many disease agents have developed strategies to overcome extremes of reservoir qualities like population size and density. Every infectious agent spreads easier when its hosts are closer together. Zoonoses must be dealt with at the interface of human and animal health by all available information. Lessons learned from the emergence of and response to agents like West Nile virus, H5N1 avian influenza, SARS and bovine spongiform encephalopathy, the cause of new-variant Creutzfeldt-Jakob disease in humans, must be used to create better plans for response and meet the challenge for public health and biodefense.     

Clostridial enteric infections in pigs.

Clostridium perfringens types A and C and Clostridium difficile are the principal enteric clostridial pathogens of swine. History, clinical signs of disease, and gross and microscopic findings form the basis for a presumptive diagnosis of C. perfringens type-C enteritis. Confirmation is based on isolation of large numbers of type-C C. perfringens and/or detection of beta toxin in intestinal contents. Diagnosis of C. perfringens type-A infection, however, remains controversial, mostly because the condition has not been well defined and because type-A organisms and their most important major (alpha) toxin can be found in intestinal contents of healthy and diseased pigs. Isolation of large numbers of C. perfringens type A from intestinal contents, in the absence of other enteric pathogens, is the most reliable criterion on which to base a diagnosis. Recently, beta2 (CPB2) toxin-producing C. perfringens type A has been linked to disease in piglets and other animals. However, implication of CPB2 in pathogenesis of porcine infections is based principally on isolation of C. perfringens carrying cpb2, the gene encoding CPB2, and the specific role of CPB2 in enteric disease of pigs remains to be fully defined. Clostridium difficile can also be a normal inhabitant of the intestine of healthy pigs, and diagnosis of enteric infection with this microorganism is based on detection of its toxins in feces or intestinal contents.     

Probiotic alternatives to reduce gastrointestinal infections: the poultry experience

The intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of beneficial bacterial communities and metabolites from these complex ecosystems has varying consequences for host health. This hypothesis has led to the introduction of novel therapeutic interventions based on the consumption of beneficial bacterial cultures. Mechanisms by which probiotic bacteria affect the microecology of the gastrointestinal tract are not well understood, but at least three mechanisms of action have been proposed: production/presence of antibacterial substances (e.g., bacteriocins or colicins), modulation of immune responses and specific competition for adhesion receptors to intestinal epithelium. The rapid establishment of bacterial communities has been thought to be essential for the prevention of colonization by pathogenic bacteria. Some animal models suggest that the reduction in bacterial translocation in neonatal animals could be associated with an increase in intestinal bacterial communities and bacteriocin-like inhibitory substances produced by these species. This review emphasizes the role of the intestinal microbiota in the reduction of the gastrointestinal infections and draws heavily on studies in poultry.     

Cryptosporidium and host resistance: historical perspective and some novel approaches

Cryptosporidium parvum is recognized as a major cause of diarrheal disease in neonatal bovine calves. In addition, this protozoan parasite has emerged as an important cause of disease in both immunocompromised and immunocompetent humans. Despite years of research, no consistently effective means of prevention or treatment are readily available for cryptosporidiosis in any species. Infection through ingestion of contaminated water has been widely documented; C. parvum was reported to be responsible for the largest waterborne outbreak of infectious disease in US history. In addition to its role as a primary disease agent, C. parvum has potential to initiate or exacerbate other gastrointestinal disorders, such as inflammatory bowel disease. Thus, control of C. parvum infection in both animals and humans remains an important objective. Research in our laboratory has focused on understanding mechanisms of resistance to C. parvum. We have demonstrated that acquisition of intestinal flora increases resistance to C. parvum. Substances present in the intestinal mucosa of adult animals can transfer resistance when fed to susceptible infants. Both expression of intestinal enzymes and rate of proliferation of epithelial cells may be altered following C. parvum infection. These and other changes may have profound effects on host resistance to C. parvum.