The foot-and-mouth disease epidemic in Dumfries and Galloway, 2001. 1: Characteristics and control

The foot-and-mouth disease epidemic in Dumfries and Galloway in south-west Scotland comprised 177 infected premises (IPS) in 24 geographical clusters, and ran from March 1 until May 23, 2001. Initial seeding of infection was by livestock (predominantly sheep) that had passed through Longtown Market in adjacent Cumbria. Thereafter, spread within existing, and to new, clusters was associated with the movement of personnel and vehicles, with further transmission by Longtown Market contacts and across common boundaries. Sheep and cattle premises were equally affected. After the peak of the epidemic at the beginning of the third week of March, the upper possible limit of attack rates for premises contiguous to IPS, and premises within 3 km, remained around 10 per cent, with new clusters emerging more distantly. Control procedures included traditional methods of slaughter of all animals on IPS and, elsewhere, of animals considered by veterinary assessment to be Dangerous Contacts; movement restrictions; enhanced biosecurity; tracing of potential sources and spread of virus; and surveillance of premises subsequently considered at risk. These methods were supplemented by the novel pre-emptive slaughter, without veterinary assessment, of all susceptible livestock on all premises contiguous to IPS, and of small ruminants and pigs within a 3 km radius (known as the Protection Zone) around IPS. In total, approximately 80,000 cattle, 564,000 sheep, 2600 pigs and 500 goats were slaughtered, the novel methods accounting for 29 per cent of all cattle and 75 per cent of all sheep killed. Limitations of existing national databases necessitated the development of local databases to administer control procedures.     

TSE pathogenesis in cattle and sheep

Many studies have been undertaken in rodents to study the pathogenesis of transmissible spongiform encephalopathies (TSE). Only a few studies have focused on the pathogenesis of bovine spongiform encephalopathy (BSE) and scrapie in their natural hosts. In this review, we summarize the most recent insights into the pathogenesis of BSE and scrapie starting from the initial uptake of TSE agents and crossing of the gut epithelium. Following replication in the gut-associated lymphoid tissues (GALT), TSE agents spread to the enteric nervous system (ENS) of the gut. Infection is then carried through the efferent fibers of the post-ganglionic neurons of the parasympathetic and sympathetic nervous system to the pre-ganglionic neurons in the medulla oblongata of the brain and the thoracic segments of the spinal cord. The differences between the pathogenesis of BSE in cattle and scrapie in sheep are discussed as well as the possible existence of additional pathogenetic routes.     

The foot-and-mouth disease epidemic in Dumfries and Galloway, 2001. 2: Serosurveillance, and efficiency and effectiveness of control procedures after the national ban on animal movements

After the foot-and-mouth disease (FMD) epidemic in Dumfries and Galloway in south-west Scotland in 2001, serosurveillance of sheep remaining in the 3 km radius Protection Zones around Infected Premises (IPS), and within a 10 km radius of IPS, revealed no evidence of infection. The epidemic was brought under control by a range of traditional techniques: slaughter of all animals on IPS and of veterinary-assessed Dangerous Contacts (DCS), movement restrictions, biosecurity, tracing of potential sources and spread of virus, and surveillance of At-Risk premises. Novel pre-emptive slaughter of FMD-susceptible animals on premises contiguous to IPS, and small ruminants and pigs on premises within 3 km of IPSs, commenced after the epidemic had peaked. Most of the traditional control procedures were undertaken quickly and with appropriate priority. Animals on IPS were usually slaughtered within one day of confirmation, and veterinary-assessed DCS within two days of confirmation of relevant IPS (a median of two days). The pre-emptive contiguous and 3 km culls took somewhat longer (medians of five and 17 days, respectively). IPS were most commonly identified as a result of reporting by farmers or their veterinarians (72 per cent of IPS); veterinary clinical patrols identified 16 per cent, while veterinary assessment of DCS and tracing each identified 5 per cent. No evidence of infection was found on any pre-emptively contiguously culled premises, and IPS were declared only on three 3 km cull premises. The time from estimated first lesion to end of slaughter on an IP was found, by regression analysis, to be a key component in effective control, manifested by a reduction in the estimated dissemination rate (EDR); there was little evidence that the intensity of contiguous culling affected the EDR. Patrols and serological surveillance of residual animals within 10 km of IPS, supported by more extensive evidence from elsewhere in the UK, suggested that cryptic infection in sheep was not widespread. Ultimately, there was insufficient evidence to support the effectiveness of 3 km pre-emptive culling as a control procedure.     

Physiologic studies of experimentally grain-engorged cattle and sheep.

Seven sheep weighing 34 to 41 kg, each, 3 steers and 1 heifer weighing 230 to 460 kg each, were experimentally, "overfed" (induced grain engorgement). The most significant changes occurred in ruminal ingesta pH, blood pH, packed cell volume (PCV), hemoglobin (Hb), carbon dioxide pressure (PCO2, total CO2 (volume %), blood D-lactic acid, blood HCO3, and base excess. There was no common denominator that was especially pathognomonic.     

Location of immunoglobulins in the skin of cattle and sheep.

The pattern of distribution of immunoglobulins (Ig) found within the skin of cattle and sheep was the same in both species. IgA was detected mainly in the sweat gland duct and in the intercellular spaces of the living epidermis. IgG was also located at the latter site but was found in greater amounts throughout the dermis and in the endothelium of the blood vessels. IgM was primarily located at the basement membrane of the epithelial structures, in the hair papilla and in the walls of the blood vessels. Lower concentrations of IgM were also detected in the upper dermis.     

牛羊东毕血吸虫病的防治

吉林省西北部幅员辽阔 ,地势平坦 ,有大小泡沼多达 1 2 5 0个 ,许多河流进草原后形成无尾河 ,或流进泡河内。雨季雨水流入洼地 ,长期浸泡低洼草场 ,极利于东毕血吸虫的中间宿主椎实螺的繁殖生长。1 986年和 1 998年该地区先后两次牛、羊东毕血吸虫病流行 ,造成了较大经济损失。1　病原土耳其斯坦东毕吸虫属于裂体科 ,东毕属吸虫 ,主要寄生于牛羊肠系膜静脉 ,引起牛、羊东毕血吸虫病。其中间宿主为水生椎实螺。牛、羊粪便中的虫卵 ,在水中孵化成毛蚴 ,侵入螺体 2 1天后发育成尾蚴逸出 ,在水中经皮肤侵入终末宿主体内 ,移行到肠系膜静脉管中生…     

牛羊超数排卵方法研究进展

超数排卵(简称超排)可诱导大量卵泡成熟排卵,增加可移植胚胎的数量,在家畜胚胎移植中起着至关重要的作用,同时也是进行转基因动物生产和动物克隆等研究的基础手段之一。目前家畜的超排主要用于牛羊,以使用FSH或PMSG为主。也有人在试验通过抑制素免疫进行,效果明显,但超排个体反应差异较大,这一问题目前仍无法解决。本文就牛羊超排方法的研究进展进行综述,以使人们对超排有更多了解,促进超排方法的改进,超排效果的提高。1基础超排方法初级卵泡经过征集、选择、优势化,而发育到可排卵阶段,其间绝大多数卵泡(如反刍动物99%以上)的命运是闭锁…     

Isolation of Mycobacterium paratuberculosis from sheep and cattle in Iceland.

Isolation of Mycobacterium paratuberculosis from sheep and cattle in Iceland. Acta vet. scand. 1979, 20, 191–199. — Culture experiments concerning the Icelandic variant of Mycobacterium paratuberculosis are described. Various decontaminating agents and culture media were employed and the colonial morphology of freshly isolated strains on different media described. The growth rate and culture requirements are compared with those of the Norwegian goat-pathogenic variant of M. paratuberculosis. For primary isolation modified Herrold’s medium gave the best results. However, on all the various culture media used, the growth of the Icelandic variant was much more sporadic than that of the Norwegian goatpathogenic variant. It is concluded that bacteriological culture is not useful for the diagnosis of Johne’s disease caused by the Icelandic variant of M. paratuberculosis.     

Vitamin E status of cattle and sheep. 2: Survey of liver from clinically normal cattle and sheep for alpha-tocopherol

Analysis of liver from clinically normal animals showed a mean alpha-tocopherol level of 20 mg/kg for cattle and 6 mg/kg for sheep. The corresponding normal values (mean +/- 2 S.D.) were 9 to 44 mg/kg and 1.8 to 20 mg/kg. The usefulness and assessment of tocopherol analyses on liver and serum samples are discussed in the light of these normal values and routine diagnostic submissions.