猪群血清学检测在生产中的应用

为了减少群体疾病暴发所带来的经济损失,猪群疾病状况的预知变得尤为重要,而血清抗体的监控是疾病监控的一个重要手段.     

Questionnaire survey of disease prevalence and veterinary treatments in organic layer husbandry in the Netherlands

Disease prevalence and veterinary treatments in organic animal production differ from those in conventional systems. In order to gather information about current practices in organic layer husbandry, 33 organic egg producers of 16 small, 12 medium-sized, and 5 large farms were asked to complete a questionnaire on disease prevalence and treatments. On these farms, the mean mortality was 9% and the mean laying percentage was 79%. In contrast with the regulations for organic farming, the use of chemotherapeutics was not recorded on 30% of the farms. One third of the farmers were not aware of the type of vaccination given to their hens, and on the other farms hens had been vaccinated as pullets against nine or more viral and bacterial diseases. Several health problems were mentioned, such as feather pecking, red mites, helminths, infectious bronchitis, colibacillosis, and coccidiosis. On 19 farms, diseases were treated with homeopathic, phytotherapeutic, or other alternative medicines; on 10 of these farms chemotherapeutics were also used. On 4 farms only chemotherapeutics were used, on 10 farms no products were used, and on some farms up to seven products were used. Although quite a large number of organic layer farmers in the Netherlands used homeopathic, phytotherapeutic, or other alternative medicines, the use of chemotherapeutics is currently inevitable to prevent animal suffering or distress in organic husbandry.     

An abattoir survey of the prevalence of gastro-intestinal helminths andStephanurus dentatus in pigs in Belize

In an abattoir survey in Belize 137 pigs were examined for gastro-intestinal helminths and Stephanurus dentatus. Hyostrongylus rubidus, Physocephalus sexalatus, Globocephalus species and Trichostrongylus colubriformis were recorded for the first time. Ascarops strongylina, Ascaris suum, Macracanthorynchus hirudinaceus, Strongyloides ransomi, Trichuris suis, Oesophagostomum species and S. dentatus were also found. Oesophagostomum species (45%) and S. dentatus (42%) were the most prevalent. The prevalence of infection with different species was compared between pigs of different origin, breed and management. Differences were apparently due to management; most species were more common in poorly managed pigs. M. hirudinaceus and S. dentatus were used as "markers" to indicate poor management. The usual methods of faecal egg counting were found to be unreliable for the diagnosis of M. hirudinaceus infection.     

RNA干扰技术在动物抗病育种中的应用前景

动物疾病尤其是病毒性疾病一直是畜牧业亟待解决的问题,随着转基因技术的出现,生产遗传修饰动物来抵抗特定传染病的策略备受关注。从长远利益来看,这种基因工程动物从遗传本质上提高了畜禽的抗病能力。转基因抗病育种在未来可能成为减少动物传染性疾病的最有前途的方法之一。RNA干扰是双链RNA特异性诱导同源基因表达沉默的现象。研究证实,RNA干扰在细胞水平,小鼠模型以及动物个体的抗病毒效果是非常明显的,RNA干扰技术作为抗病毒策略为生产抗病转基因动物提供了光明的应用前景。RNA干扰技术介导的抗病转基因动物的研究相继取得了阶段性进展,抗疯牛病转基因羊和牛以及抗内源性逆转录病毒猪已经成功获得,虽然目前获得的转基因动物类型有限,但为继续生产抗病转基因家畜提供了有效的参考和依据。     

A needs-assessment and demographic survey of infection-control and disease awareness in western US animal shelters

A cross-sectional needs-assessment survey was used to characterize animal shelters in a 6-state region in the western US and describe infection-control practices and disease awareness. Survey questions focused on shelter demographics, infection-control practices and policies, awareness and concern over infectious and zoonotic diseases, staff and volunteer training relating to infection-control and disease awareness, use of diagnostic tools, and isolation procedures and protocols. Fifty percent of shelters responded to the survey and represented a wide variety of shelter types, sizes and locations. The top-three diseases of concern to shelters were feline upper respiratory disease (FURD), canine parvovirus and ringworm. Concern over these diseases was greater in open-admission shelters (compared to limited admission or no-kill/sanctuary) (OR 3.7, 95% CI 1.1-12.5) and in shelters with a desire for more zoonotic-disease training (OR=6.1, 95% CI 1.5-24.8) (compared to shelters desiring infectious-disease training, training on cleaning and disinfection or those who have no need for further training). In 45% of responding shelters many to most animals arrive with infectious diseases. Written protocols for preventive medicine exist in 88% of shelters, cleaning and disinfection protocols in 75%, specific disease protocols for outbreak situations in 36% and infection-control manuals in 15%. Veterinarians are in charge of infection-control in 6% of shelters. Approximately 45% of shelters vaccinate dogs and cats for rabies. Infectious-disease training is provided to 30% of staff and 35% of volunteers upon hire. Overall, volunteers received less training in infectious- and zoonotic-disease identification, prevention and control than staff members. Ninety percent of shelters said they would benefit from training in infectious and zoonotic disease. Results from this study can be used to assess and address needs in animal shelters relating to infection-control, infectious and zoonotic-disease awareness and can help guide development of shelter staff and volunteer training.     

目前我国畜禽疫病发生的现状及控制(续)

畜禽传染病的发生是我国规模化饲养的一个特别重要的制约因素，也是畜牧业发展成败的关键，控制与消灭动物疫病是一项系统工程，要求多方面的合作与努力。因此，必须建立以预防为主，防检结合，以检促防的畜禽疫病防制工作运行机制，开创适合我国国情和符合市场经济的兽医工作新秩序，保障我国畜牧业的健康发展。特提出以下几点建议：     

转基因植物疫苗的开发及其在动物传染病防治中的应用

自首例植物疫苗投入市场来,许多植物物种经过遗传改造后用来表达抗原蛋白用于保护动物和人类健康。由于兽用疫苗比人用疫苗受到的限制比较少,所以吸引了大量的研究者、公司和投资商的关注,从而推动了转基因植物疫苗的迅速发展。植物疫苗可以直接口服免疫,避免了纯化过程,降低了生产成本,并逐渐走向成熟。本文就转抗原植物疫苗在发展中的问题、解决方案及其在动物传染病防治中的应用作一详细报道。     

市级动物疫病防控信息化管理系统功能设计

我国动物疫病流行日趋复杂,而传统防控工作方式效率亟待提高。信息化能有效提高动物疫病防控管理工作效率,有利于对动物疫情的快速预警、反应、控制和溯源。本文介绍市级动物疫病防控信息化管理系统的功能设计,重点分析基础信息数据库、物资管理系统、动物疫病监测、疫情预警、疫情调查处置等功能模块,形成市级动物疫病防控大数据和网络化管理平台,实现动物防疫场点、人员、疫苗、物资和工作抽查等网络化管理,为动物疫病防控行政决策提供技术支持,切实提高基层防疫工作效率。     

Liver fluke infections of cattle in Mali. An abattoir survey on prevalence and geographic distribution

Six hundred and ninety two cattle, slaughtered in various abattoirs in Mali between August 1983 and November 1984 were examined for evidence of Fasciola gigantica and Dicrocoelium hospes infections. A great variation in geographic prevalence was observed. Sufficient knowledge was acquired to demonstrate both the importance of fascioliasis in some areas and also the high prevalence of D. hospes in other areas. We suggest that the difference in prevalence from one geographic area to another is influenced by local climatic conditions, presence or absence of rivers and lakes, and differences in livestock management practices by various ethnic groups.     

Estimation of animal-level prevalence from pooled samples in animal production

Often, the prevalence of an infection in the animal-production sector is determined at the group level. The prevalence at animal level (p) gives more-precise information on the infection status of the sector. This paper shows that pooled-sample data together with mathematical models allow for estimation of p. For this, model assumptions have to be made on the variation of p between groups separated in space and/or time. Formulas were derived for four models that were based on different assumptions. Model 1 assumed that p has the same value for all groups. Models 2–4 assumed that some of the groups were not infected. In addition, model 2 assumed that p has the same value for all infected groups; model 3 assumed that for an infected group, p is equal to either p₁ or p₂; and model 4 assumed that p was Beta distributed among infected groups. The models were applied to data sets on Salmonella infection in broiler flocks, including serotype data dominated by S. Hadar and S. Paratyphi B, var. Java. Based on likelihood-ratio tests, models 3 and 4 consistently fitted significantly better to the data. The applicability of model 4 is numerically bounded, related to the shape of the Beta distribution of p. Model calculations show that flock-level prevalence of Salmonella is much higher after than before slaughter. This difference (which possibly is related to different types of samples) is much smaller at the animal level. An important result of the estimation of p is that it in turn allows for an estimation of the proportion of false-negative groups — which is important in estimating the effect of veterinary or public-health measures.     

Environmental sampling for Salmonella spp. in Colorado animal shelters

Salmonella enterica is an important zoonotic agent and nosocomial infections and epidemics have occurred in animal facilities. The objective of this study was to estimate the prevalence of Salmonella in the environment in animal shelters. From 12 to 25 samples were taken from each shelter to represent environmental contamination. Samples were collected from surfaces in areas used by animals and in public access areas including animal receiving rooms, kennels, paediatric wards, treatment, visitation rooms, isolation, euthanasia, outdoor runs and play areas, reception rooms, animal transport vehicles, offices, break rooms and restrooms. Samples were tested for Salmonella and compared within shelters to identify high- and low-risk areas; and between shelters to identify differences in environmental contamination by geographical location, infection control policies, and shelter size characteristics. Twenty-eight per cent of sampled Colorado shelters had environmental Salmonella contamination. Two regions in the eastern 1/3 of the state had prevalences of 30% and 100%. Within-shelter sample prevalence ranged from 0 to 100%. Results of this study indicate that animal shelters can be frequently contaminated with Salmonella spp., a variety of Salmonella species may be present, contamination can be widespread within a facility and recovered isolates may harbour antibiotic resistance The findings from this study may influence and help focus educational policy on issues of infection control and zoonotic disease awareness in animal shelters.     

Long-term survey on Trichinella prevalence in wildlife of Slovakia

In Slovakia, monitoring the prevalence of Trichinella spp. in wildlife was performed since 2000 in the main reservoir animals, the red fox (Vulpes vulpes) and wild boar (Sus scrofa), using artificial digestion method as recommended by International Commission on Trichinellosis. The results of investigation performed in 5270 red foxes showed that Trichinella infection is widespread across Slovakia and prevalence increased significantly from 4.9% in 2000 to 20.5% in 2007. Recently, a higher Trichinella prevalence (0.11%) in wild boars was also demonstrated. The results indicate that foxes and wild boars are involved in the spread of Trichinella, although the latter host species seems to play a secondary role in the maintenance of the sylvatic cycle in Slovakia. Trichinella britovi is the predominant species circulating in Slovakia, both in foxes and wild boars, and Trichinella spiralis occurs only sporadically. Mixed infections of T. britovi and Trichinella pseudospiralis were recorded in 2005 in one wild boar from Eastern Slovakia and in 2006 in one red fox from the same region. These findings are important with respect to an outbreak caused by T. pseudospiralis in a pig farm in the same district 3 years ago. This study provides a complex picture on Trichinella occurrence in all regions of Slovakia and may be a good basis for evaluating the risk of parasite transmission to the domestic cycle and human beings.     

An estimated prevalence of Johne's disease in a subpopulation of Alabama beef cattle.

The objective of this study was to estimate the overall prevalence of animals that were infected with Mycobacterium avium ssp. paratuberculosis in a subpopulation of Alabama beef cattle. This was determined using a commercial enzyme-linked immunosorbent assay (ELISA) for the detection of M. avium ssp. paratuberculosis-specific antibodies in serum. Serum was collected from 79 herds that were participating in the Alabama Brucellosis Certification program. A total of 2,073 beef cattle were randomly tested by selecting 30 animals per herd in herds greater than 30 and selecting all animals in herds 30 and less for testing. It has been estimated that the commercial ELISA test used has a 60% sensitivity and a 97% specificity. Of the 79 herds tested, 29 herds were seronegative, 24 herds had 1-2 positive animals, and 26 herds had 3 or more seropositive animals. The average number of infected animals per positive herd was 3.3. In addition, a calculated minimum of 53.5% of the herds were identified as Johne's positive herds with a 95% confidence level. Of the total number of animals tested, 8.0% (166/2,073) of them were positive by the ELISA. After adjustments for test sensitivity and specificity and the proportion of animals sampled per herd, the true prevalence was calculated to be 8.75%. These data suggest that approximately 50% of the herds are infected with M. avium ssp. Paratuberculosis, and the overall prevalence of infection in Alabama beef cattle is approximately 8%, which correlates with other previously published regional estimates.     

Implications of mycotoxins in animal disease

Mycotoxins are formed on animal feeds when conditions of moisture and temperature permit the growth of naturally occurring toxigenic fungi. In general, mycotoxins are low molecular weight, nonantigenic substances, many of which are relatively heat stable. Mycotoxins can cause acute disease episodes when animals consume critical quantities of them. Specific toxins affect specific organs or tissues such as the liver, kidney, oral and gastric mucosa, brain, or reproductive tract. In acute mycotoxicoses, the signs of disease often are marked and directly referable to the affected target organs. Most frequently, however, concentrations of mycotoxin in feeds are below those that cause acute disease. At lower concentrations, the effects of mycotoxins are more protean. They reduce the growth rate of young animals, and some interfere with native mechanisms of resistance and impair immunologic responsiveness, making the animals more susceptible to infection. These effects on immunity and resistance are difficult to recognize because the signs of disease are associated with the infection rather than with the mycotoxin that predisposed the animal to infection. Animals vary in their susceptibility to some mycotoxins, according to the species and age of animal; young growing animals are more susceptible to certain mycotoxins than are adults. The major effects, sources, and dose response relationships of mycotoxins important to the health of food-producing animals are presented in accompanying tables.     

浅谈兽药的合理使用

近些年来，畜牧养殖业发展迅速，但是由于种种原因．畜、禽疫病越来越多，越来越复杂。于是，在一些养殖户中．有病乱投医、乱用药的现象频繁出现，经常出现因用药不当造成中毒和动物死亡的情况，抗菌药物的耐药现象也相当普遍，这与药物的不合理使用有很大关系。为了更好地使用兽药，做到及时、有效控制疫病，保证畜产品安全以及提高经济效益．笔者认为应该注意以下几个问题：