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1.
《国外畜牧学(猪与禽)》2000,(2)
加拿大安大略兽医学院的Ｊ Ｗｉｌｓｏｎ说 ,经典型坏死性肠炎是很容易识别的 ,并且见于全世界大多数家禽生产地区。然而 ,亚临床坏死性肠炎则很难识别但却可引起很多问题 ,比如 ,性能下降、垫料潮湿、肝脏坏死以及温和型肠炎。为对付坏死性肠炎 ,有三个因素是必须加以注意的。第一 ,必须应用能抗产气荚膜梭状芽孢杆菌的有效抗菌药 ;第二 ,必须对正在应用的球虫病防制方法进行重新评价 ,因据认为鸡患了亚临床的低水平球虫病后肠道粘膜上皮的完整性就会受到破坏从而就容易发生坏死性肠炎 ;第三 ,饲喂高水平的小麦或大麦容易引发坏死性肠炎 ,… 相似文献
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鸡坏死性肠炎的防制ＳｔｅｐｈｅｎＡ．著崔水保摘译杨圣典校１坏死性肠炎的症状１９６１年英国首次报道鸡坏死性肠炎。此后，世界大多数家禽生产国都有报道。早期的工作者用魏氏梭状芽胞杆菌（现在叫产气荚膜梭状芽胞杆菌）感染小鸡复制此病。该病呈散发性，主要发生于肉... 相似文献
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鸡坏死性肠炎(necrotic enteritis,NE)是现代化肉鸡集约养殖生产中最为突出的肠道疾病之一,给家禽产业带来了巨大的经济损失。随着世界范围内的立法限制、禁用抗生素生长促进剂,鸡坏死性肠炎的发病率在全球范围内呈上升趋势,这对家禽的生产和健康产生严重威胁。因此,迫切需要新的技术和新的产品代替抗生素来预防和控制鸡坏死性肠炎。作者着眼于NE的危害和疫苗、噬菌体、卵黄抗体、植物提取物、酸化剂、益生菌、低聚糖与微生物多糖等生物性防控进展,综述了目前有效预防和控制鸡坏死性肠炎的生物性措施的最新研究情况,既为鸡坏死性肠炎生物性防控提供技术参考,也为其深入研究提供了理论思考。 相似文献
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鸡坏死性肠炎是一种急性消化道传染病,该病在养鸡生产中发生较多,常给养鸡业带来经济损失。以一起河北省涞水县某养殖场发生的鸡坏死性肠炎为例,对该病的临床症状、病理变化、诊断方法及防治措施作一介绍,以期为有效防控该病提供参考。 相似文献
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鸡坏死性肠炎是一种急性消化道传染病,该病在养鸡生产中发生较多,常给养鸡业带来经济损失。以一起河北省涞水县某养殖场发生的鸡坏死性肠炎为例,对该病的临床症状、病理变化、诊断方法及防治措施作一介绍,以期为有效防控该病提供参考。 相似文献
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王志全 《畜牧兽医科技信息》2018,(3)
正坏死性肠炎病是由产气荚膜梭菌引起的一种急性非接触性传染病,发病急,死亡率高,给畜禽养殖业带来巨大经济损失。随着规模化养殖业的快速发展,公共卫生安全问题日益严峻,坏死性肠炎的发病率也有所升高,所以广大养殖户和兽医临床工作者应对此病更加重视。本文从病原学、流行病学、诱发因素、临床特征、剖检病变、诊断和防治等方面进行阐述,为坏死性肠炎病的研究提供参考依据。1病原学本病的病原是产气荚膜梭菌,革兰氏阳性芽孢杆菌,在 相似文献
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猪魏氏梭菌病是由魏氏梭菌所引起猪的肠道性疾病,也叫做猪梭菌性肠炎、猪传染性坏死性肠炎、肠毒血症。各年龄段猪于各季均可发病。该病虽发病率不高,但死亡率较高,来不及治疗而死亡,对养猪业危害极大。2012年2月,我市某猪场发生该病,并 相似文献
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Necrotic enteritis is an acute gastrointestinal infectious disease with high morbidity and mortality which caused by Clostridium perfringens. The disease not only harms the livestock health and animal welfare,but also has been an emerging threat for breeding industry and human health. Antibacterial drugs played a positive role on preventing this disease,however,drug-resistant strains were increasing with irrational use of antibiotics,the incidence of necrotic enteritis has drastically increased, prevention and treatment of it faced severe challenges. The author reviewed the characteristics of necrotic enteritis include the etiology,physicochemical properties, epidemiology and clinical signs,at the same time, the control measures and common drugs were summarized,and the new development trend and direction for prevention and treatment necrotic enteritis was objective analyzed, aiming to establish a comprehensive understanding of the disease,provide references for prevention and treatment of the disease. 相似文献
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《The Journal of Applied Poultry Research》2015,24(1):91-97
There is growing acknowledgement that use of antibiotics in people is the primary driver of antibiotic-resistant infections in humans [1, 7., 8., 9.], however, antibiotic-free production of poultry has become increasingly popular. Consumer perception is that antibiotic-free produced poultry is superior to conventionally raised poultry in spite of a lack of supporting scientific data [2]. A widely accepted definition of antibiotic-free poultry in the United States is that there is “no use of antibiotics (including ionophore anticoccidials) at the farm.” That means that coccidiosis and necrotic enteritis prevention must rely on synthetic or “chemical” anticoccidials, or on live coccidiosis vaccines, or on rotations between drugs and vaccines. The problem with this approach is that chemical anticoccidials (with the exception of nicarbazin) build coccidial resistance much quicker than ionophores and must be rested for a prolonged period of time. Further, there are limited numbers of anticoccidials of this class on the market. Moreover, unlike the ionophores, the chemicals do not have an antibiotic effect that aids in the prevention of necrotic enteritis and typically nicarbazin is only used during the cool months. Additionally, live coccidiosis vaccines induce immunity by invading, replicating, and cycling through the intestines. The coccidial infection, therefore, damages the intestinal epithelium and predisposes the birds to necrotic enteritis [3]. These intestinal health problems lead to bird welfare issues that must be addressed in the antibiotic-free production system. Likewise, it is generally acknowledged that production efficiency (weight gain, feed conversion ratio, mortality and yield) is adversely impacted in the antibiotic-free production system [4]. Thus, antibiotic-free production results in a greater carbon footprint and is less efficient [5., 6.]. Companies considering raising antibiotic-free poultry must be aware of the expected adverse effects on bird health, production efficiency, and cost. 相似文献
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Timbermont L Lanckriet A Gholamiandehkordi AR Pasmans F Martel A Haesebrouck F Ducatelle R Van Immerseel F 《Comparative immunology, microbiology and infectious diseases》2009,32(6):503-512
Since the ban on growth-promoting antibiotics in animal feed in the European Union, necrotic enteritis has become a major cause of mortality in broiler chickens. Despite the importance of the disease, the pathogenesis is still not completely understood. In the current study, Clostridium perfringens strains isolated from healthy flocks and isolates from outbreaks of necrotic enteritis were evaluated for the ability to cause gut necrosis in an intestinal loop model in laying hens and in an experimental infection model in broilers. High, intermediate and low alpha toxin producing strains were chosen from each isolation source. Only the isolates from field outbreaks induced necrotic gut lesions, independent of the amount of alpha toxin produced in vitro. It was also shown that alpha toxin producing isolates from calf hemorrhagic enteritis cases were not able to induce necrotic enteritis in poultry. These results suggest the presence of host specific virulence factors in C. perfringens strains, isolated from chickens with intestinal necrotic enteritis lesions. 相似文献
14.
《The Journal of Applied Poultry Research》2015,24(2):145-156
This study investigated the effects of necrotic enteritis challenge or a necrotic enteritis challenge with an additional challenge from dietary aflatoxin B1 compared to broilers that were unchallenged. Also tested were products designed to help alleviate those effects. Lesion scores were higher in broilers challenged to induce necrotic enteritis, but this did not increase with added aflatoxin. The presence of dietary aflatoxin during a necrotic enteritis challenge significantly increased the negative effects of the necrotic enteritis challenge. During the necrotic enteritis challenge virginiamycin, Calibrin-Z, or a blend of Calibrin-Z, an organic acid, and yucca, helped to decrease the effects of the challenge. When birds are challenged with necrotic enteritis and dietary aflatoxin is present, Calibrin-Z had an advantage over all other tested products. 相似文献
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《The Journal of Applied Poultry Research》2014,23(3):557-566
Considering market demands concerning the decreased use of growth promoters and anticoccidial drugs in feed formulations, the poultry industry has been trying to reduce or eliminate the inclusion of subtherapeutic doses of antimicrobials into feed. Formulating diets not only to meet birds’ nutrient requirements for growth but also for gastrointestinal health parameters is increasingly important. Maintenance and enhancement of intestinal integrity is essential for bird performance when antimicrobials are not included in feed, as commercial poultry face numerous enteric pathogen challenges. Necrotic enteritis has reemerged as an important disease of poultry in recent years. The reduction in the use of antimicrobials in poultry feeds has been attributed as one of the main contributing factors for the increasing incidence of necrotic enteritis (NE) in commercial poultry. Mortality due to NE is extremely high (1% daily mortality), which results in great economic losses. Economic losses due to NE are not only associated with high mortality, but also associated with decreases in bird performance and FE, particularly in subclinical cases of NE. Birds that survive NE outbreaks usually have a reduced ability to digest and absorb nutrients due to extensive damage to the mucosal lining, which ultimately results in reduced profitability. 相似文献
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Necrotic Enteritis in Broiler Chickens II. Pathology and Proposed Pathogenesis 总被引：2，自引：2，他引：0 
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下载免费PDF全文 The intestines from 124 dead, sick and normal broiler chickens from 24 cases of necrotic enteritis were subjected to histological examination. Tissue sections from the duodenum, jejunum, ileum and ceca from each broiler were examined histologically for lesions of necrotic enteritis and the presence of coccidia. Lesions of necrotic enteritis were present in one or more areas of the intestine in all but six of 94 dead or sick birds and they were most common and severe in the jejunum. Coccidia were found in only small numbers in both diseased and normal birds.
Brown and Brenn stained sections showed Gram-positive bacilli intimately associated with early necrotic lesions on the tips of villi. Tissue sections from the intestines of sick birds permitted a proposed pathogenesis for this disease with the lesion starting at the tips of villi.
The similarity in pathogenesis and pathological lesions in this disease of broilers and Clostridium perfringens type C enteritis in baby pigs is discussed.
相似文献17.
Anthony L. Keyburn Xu-Xia Yan Trudi L. Bannam Filip Van Immerseel Julian I. Rood Robert J. Moore 《Veterinary research》2010,41(2)
A novel toxin, NetB, has recently been identified in virulent avian Clostridium perfringens isolates and shown to be an essential virulence factor in a clinical necrotic enteritis isolate. To assess whether NetB is more generally associated with avian necrotic enteritis isolates we have screened a range of C. perfringens strains from geographically diverse locations for both the presence and expression of the netB gene. Forty-four isolates were derived from necrotic enteritis disease cases from Australia, Belgium, Denmark and Canada and 55 isolates from healthy chickens from Australia and Belgium. The majority of strains isolated from necrotic enteritis-affected birds were netB positive (70%) and there was an absolute correlation between the presence of netB and in vitro expression of the NetB protein. Only two of the C. perfringens isolates from healthy chickens carried netB. Sequencing of the netB gene from 23 positive isolates showed that NetB is highly conserved, with only one predicted amino acid (A168T) difference, in six isolates, compared to the published sequence. This change did not alter the in vitro activity of the NetB toxin. The gene encoding the recently discovered TpeL toxin was also screened using PCR and only found in a small proportion of NetB-positive isolates from diseased birds. A selection of NetB-negative isolates, originating from diseased birds, was unable to cause disease in a necrotic enteritis induction model. This study provides further evidence that NetB is important in pathogenesis and advances our current understanding of C. perfringens virulence factors in avian necrotic enteritis. 相似文献
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《The Journal of Applied Poultry Research》2007,16(2):275-279
This study was performed to determine if the enteric disease necrotic enteritis results in higher shedding of Salmonella. Fifty percent of the chicks per pen were challenged with a naladixic acid-resistant Salmonella Heidelberg. A necrotic enteritis challenge model using a coccidia vaccine to induce intestinal epithelium damage was used to demonstrate that neither the disease necrotic enteritis nor the control of that disease with the antibiotic bacitracin methylene disalycilate had an effect on the incidence of Salmonella Heidelberg. However, the feed additive 3-nitro-4-hydroxyphenylarsonic acid, which controls the cecal coccidia Eimeria tenella, significantly reduced the amount of Salmonella Heidelberg in the environment of the chick as measured by dragswabs and also reduced the number of ceca positive in the contact chicks. 相似文献
19.
Kwon YK Lee YJ Mo IP 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(12):1613-1615
An acute disease with high mortality occurred in the ostrich farm and characterized by depression, severe diarrhea and sternal recumbency. Four dead ostriches of the farm were submitted to the National Veterinary Research & Quarantine Service, and diagnosed as necrotic enteritis. In the gross and histopathological examination, extensive diffuse fibrinonecrotic enteritis was found in the small intestine, especially jejunum. Clostridium perfringens was isolated from a pure culture from the duodenum and jejunum of these birds. Based on our current knowledge, this is the first report of an outbreak of necrotic enteritis in the ostrich in Korea. 相似文献
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Necrotic Enteritis in Broiler Chickens I. A Review of the Literature and the Prevalence of the Disease in Ontario 总被引：2，自引：2，他引：0 下载免费PDF全文
下载免费PDF全文 J. R. Long 《Canadian journal of veterinary research》1973,37(3):302-308
The available literature on necrotic enteritis in broiler chickens is reviewed.
The records of three poultry diagnostic laboratories in Ontario were examined for the years 1969, 1970 and 1971. During this period 855 (7.7%) of 11,076 consignments of broiler chickens examined were diagnosed as necrotic enteritis. The condition was most common in broilers at three weeks of age, with 66% of all cases occurring in chickens between two and four and one half weeks. The disease occurred throughout the year but it was most common during July, August, September and October. Necrotic enteritis often occurred more than once per year on a farm.
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