不同饲养环境奶牛隐性乳腺炎的流行病学调查

2002年1月至2003年10月,对苏北盐城地区几个不同饲养环境的奶牛场进行隐性乳腺炎的SMT(上海乳腺炎检验法)检测,结果显示:不同的乳区、有无运动场、原发病情况、发病是否隔离等条件的差异,隐性乳腺炎的发生率存在明显差异;不同的季节、挤奶方式、饲料的营养状况与隐性乳腺炎的发生率没有明显的关系。     

The cell count in sheep and goat milk]

The udder health of 404 sheep from 23 flocks and 397 goats from 15 herds in Lower Austria was examined. In order to determine cell levels, the Schalm Test (equivalent to the California mastitis test) and a fluoroscopic "Fossomatic" cell count appliance were employed. The resultant physiological median levels of somatic cell content were established as 71,000 cells/ml for sheep milk and 415,000 cells/ml for goat milk. Significant factors influencing the cell count levels were the milking technique in both species and age in sheep but not in goats. The pathogens most frequently isolated as causes of chronic or latent mastitis were coagulase-positive and -negative cocci.     

Defense mechanisms of the bovine mammary gland]

In the mammary gland of cattle there is a complex defense system of non-specific and specific reactions available preventing the invasion of pathogenic bacteria. Most infections occur via the teat canal, so teat canal keratin (SKK) is of particular importance in non-specific defense of the gland. The SKK serves as a physical barrier, and bacteriostatic and/or bactericidal effects of SKK lipids and proteins against certain mastitis bacteria could be demonstrated. By increasing the concentrations of lactoferrin and lysozyme in milk a reduction of mastitis frequencies could be observed. However, those high concentrations in the proteins occur only during the dry period of the cow. An improvement of the mastitis situation would also appear possible by increasing phagocytosis. The numerous trials intended to reduce mastitis by improving specific protection showed no significant success. Therefore, the most successful and cheapest means to achieve udder health remains the strict and consistent hygiene of housing, animals and mammary glands.     

奶山羊泌乳性能的研究

通过对产奶量较高的萨能奶山羊和优秀的地方品种成都麻羊的调查和分析,结果表明,萨能奶山羊不仅具有较高的产奶量,良好的乳房、乳头外特征,且日挤奶量高、与奶牛挤奶有近似的频率和真空度,适合于机械挤奶;成都麻羊尽管有较好的繁殖性能,但泌乳性能较差,不适合机械挤奶。     

Clarification of teat stenoses in cattle by ultrasound

Ultrasonography and radiography were used as an adjunct to clinical examination in the evaluation of 73 obstructed teats in 63 dairy cows. The images obtained with a 3.5 MHz and a 5 MHz linear array transducer were compared with radiographs and correlated with findings obtained at surgery. Ultrasonography and radiography allowed a correct assessment of the lesions in 68 respectively 58 teats. In five cases the obstructive lesions in the teat canal were not clearly discernible when ultrasonography was used. Radiography was the method of choice for the evaluation of the teat canal and small mucosal folds in the milk cistern. Ultrasonography was the method of choice for the detection of obstructive lesions at the base of the teat; all 14 of these cases were assessed correctly using ultrasonography versus three of 14 when radiography was used. Ultrasonography is a useful tool for the practitioner to evaluate obstructive teat lesions.     

Effects of bottom substrate and presence of shelter in experimental tanks on growth and survival of signal crayfish, Pacifastacus leniusculus (Dana) juveniles

The effects of tank bottom substrates and presence of shelter on growth, survival and condition of cheliped in the juvenile (stage 2) signal crayfish, Pacifastacus leniusculus (Dana), with an initial stocking density of 200 individuals m^?2 were investigated. In the first trial, three different tank bottom substrates with or without shelter were used. The three bottom types were loose gravel, glued gravel and bare bottom. The fastest growth both in terms of wet weight and carapace length was observed on loose gravel bottom. Also survival (range 30.1% to 49.8%) was affected by bottom type being higher on gravel bottoms than on bare bottom. Shelter improved survival only on loose gravel bottom. Bottom type influenced also the number of animals with cheliped injuries. The highest proportion of animals with no injuries (59.5%) was found on bare bottom and the proportion was about 12% and 13% units less on loose gravel and on glued gravel bottom. The presence of shelter had a marginal probability in increasing the number of animals without injuries. In the second trial, the substitution of ordinary gravel as tank bottom substrate with crushed limestone was studied. The mean final wet weights were 0.517 g on ordinary gravel bottom and 0.481 g on limestone bottom. The survivals were about 74% and 80% respectively. Limestone bottom decreased marginally final wet weight, and increased survival but did not affect the final carapace length that had a mean value of 13.6 mm. We conclude from the present experiments that the type of tanks and the rearing system used supported good growth of juvenile signal crayfish. The best growth results could be obtained by using loose gravel (or loose limestone) on the bottom of the tanks with a sufficient quantity of hiding places. However, there appears to be an increased risk for cheliped injuries on bottoms with loose materials.     

Evaluation of blood parameters from dairy cow stock with fertility disorders

The evaluation is based on 1329 blood samples from 199 farms using the offer of a fertility and feeding advisory programme. Total bilirubin, AST (GOT), GLDH, glucose, urea, inorganic phosphorus, and beta-carotene served as parameters. Considerable variations of all the parameters depending on the lactation level could be demonstrated. The problem of standardisation is discussed. Increased total bilirubin values (acute metabolic stress) often occurred one or two weeks post partum (26.9% of the cows). During lactation, the marginal value was exceeded by 24.6% of the cows. AST (GOT) values beyond the standard were seen in 19.4-30.1% of the cows, depending on the lactation level. These liver diseases were verified by a 25.5% increase in GLDH-values. Hypoglycaemic cows ranged between 18.5 and 28.5%. Oversupply of proteins shows a decreasing tendency (25.7%). During the winter months the beta-carotene supply is still a problem, with 40% of the cows not reaching the standard values.     

Diseases of nutria and their therapeutic potential

The article reports important diseases and different farming techniques of nutria. E. coli and salmonella infections are the most important bacterial diseases. Coccidiosis and strongyloidosis are frequently observed in nutria farms. Differentiated prophylactic treatment and hygiene are necessary for optimal breeding conditions.     

Health problems in fallow deer for meat production

Though fallow deer is considered very resistant to infectious diseases and parasites, diseases of different kind occur in enclosed pastures. Normally the diseases are the same as with wild animals or with farm ruminants. Diseases limited only to fallow deer are not known up to now. Parasitic diseases are a common problem, and prophylactic measures are necessary in all enclosed pastures to control parasites. Most losses in the enclosed pastures at the state farms of Grub and Romenthal caused by infections were due to necrobacillosis or to Coli bacteria. Because therapy is difficult or even impossible with wild animals, prophylactic measures are very important in enclosed pastures. Prophylaxis against Coli infections by improving the environment is possible only to a limited degree. Metabolic diseases and poisonings are mostly caused by wrong feeding.     

Aquaculture Farm Food Safety and Diseases Risk Assessment (AquaFRAM): Development of a spreadsheet tool for salmon farms

Atlantic salmon (Salmo salar) is the most significant aquaculture species in Europe, both in terms of production and economic value, with Norway, followed by Scotland and Ireland as the three major European producers. The objective of the present study was to develop a spreadsheet tool for aquaculture farm-food safety and diseases risk assessment (AquaFRAM) for salmon farms in the UK, (and possibly more widely) to encourage farms to assess potential hazards and diseases. AquaFRAM functions primarily as a self-assessment risk ranking and risk-learning tool to determine the potential of farm food safety hazards, diseases and the level of possible risk for contamination and infections. AquaFRAM has been developed using MS Excel software utilising a qualitative risk assessment approach for farmers to evaluate their food safety practices and diseases on their farms. The risk assessment is based on the risk matrix of frequency of likelihood × severity, where the farmers can judge the likelihood of the hazards occurring on their farm based on given examples or scenarios. Grounding of the model, based on severity scoring is predicated on relevant reports in the literature and expert opinion derived from a separate Delphi study. The AquaFRAM Tool has since been tested on 9 salmon companies throughout UK. All of the farms which tried and tested the AquaFRAM Tool reported it being farmer-friendly and practical. It was highlighted that the current tool focused mainly on risk reduction and not risk elimination. However, such farm food safety and diseases risk assessment tool would be helpful, and certainly timely, to further encourage farms to assess potential hazards and diseases. It is also appropriate for educational and training of full-time and seasonal farm workers.     

牛同期发情技术的研究

试验设计分别采用CIDR+PGF2α法、PGF2α一次注射法和PGF2α二次注射法3种不同处理方法对受体牛进行同期发情处理。结果显示:育成牛的同期发情率85.9%,显著高于带犊经产牛64.1%(P<0.01)。带犊3个月以上的经产牛的同期发情率明显高于带3个月以下的经产牛的同期发情率(P<0.01)。舍饲情况下,CIDR+PGF2α处理后的同期发情率为91.4%,受体移植可用率为74.3%,高于单独一次PGF2α或两次PGF2α处理,另外,CIDR+PGF2α处理受体牛同期发情时间比两次PGF2α早12h,而且同期化发情程度高于2次PGF2α。但CIDR+PGF2α和两次PGF2α处理同期发情方法对受体牛胚胎移植妊娠率没有影响。     

Infectious pancreatic necrosis virus isolated from farmed rainbow trout and tilapia in Kenya is identical to European isolates

Infectious pancreatic necrosis virus (IPNV) is an aquabirnavirus that causes serious diseases in a variety of fish species worldwide. It has been isolated from a large number of healthy fresh and marine water fish. Prior to this study, there was no record of the presence of IPNV infection in Kenya. Here, the presence of IPNV in farmed rainbow trout and tilapia was examined in Nyeri County of central Kenya. Head kidney samples taken from five rainbow trout and three tilapia farms and stored in RNALater^® were processed by PCR followed by sequencing of a segment A fragment covering nucleotide positions 2,120–2,343 bp. IPNV was detected in all the farms sampled with infection ratios ranging from 0.3 to 0.78 although the infections were not associated with any specific clinical signs of disease. These findings were supported by immunohistochemistry staining of the virus in the kidney and exocrine pancreas of rainbow trout. Sequence alignment and phylogenetic analysis revealed that the Kenyan isolates were identical to European isolates, suggesting a common origin. These findings highlight the need for better biosecurity procedures with more stringent surveillance programmes and control for fish diseases, especially focusing on imported breeding materials to Kenya.     

奶牛乳铁蛋白基因PCR-RFLP与隐性乳房炎的相关性分析

采用CMT方法检测奶牛的乳房炎发病情况,筛选120头分别设为对照组(健康奶牛)、隐性乳房炎组(试验组),每组60头,用限制性片段长度多态性(RFLP)分析技术,检测乳铁蛋白(Lf)基因启动子区域的RFLP多态性。结果表明:不同组别的奶牛Lf基因启动子区域存在RFLP多态性,说明该多态性与乳房炎存在一定关系。     

An assessment of salmon farms and wild salmonids as sources of Lepeophtheirus salmonis (Krøyer) copepodids in the water column in Loch Torridon, Scotland

Wild salmonids and farmed salmon can both be sources of Lepeophtheirus salmonis (Krøyer, 1838) larvae . Farmed salmon smolts free of L. salmonis infections are stocked in sea cages and may subsequently contract L. salmonis infections, probably from wild fish. The contribution of gravid L. salmonis at Atlantic salmon, Salmo salar L., farms to populations of L. salmonis larvae in the water column has in the past been based on estimated parameters, such as louse fecundity. This present study augments these calculations by combining empirical data on densities of infective L. salmonis copepodids in the field with estimates of the number of gravid L. salmonis on farmed and wild salmonids in Loch Torridon. Data collected between 2002 and 2007 show a significant correlation between mean densities of L. salmonis copepodids recovered in the water column and the numbers of gravid L. salmonis at the local salmon farms. Generally, the farms with greatest numbers of salmon were observed to have stronger correlations with densities of copepodids in the water than the farms with fewer fish. The study suggests that louse management approaches, e.g. treatment trigger levels, need to take account of individual farm biomass, or numbers of fish. This study highlights the importance of control of L. salmonis on salmon farms for the co-existence of both wild salmonid populations and the aquaculture industry.     

Designing an in‐house ELISA to detect antibody against viral haemorrhagic septicaemia virus using recombinant N protein in Iranian farmed rainbow trout (Oncorhynchus mykiss)

Viral haemorrhagic septicaemia (VHS) is one of the most important viral diseases in rainbow trout that has caused great losses to Iranian rainbow trout aquaculture industry in the last 3 years. Therefore, rapid and reliable diagnosis of VHS virus infections is of great importance. An enzyme linked immunosorbent assay (ELISA) method was performed to study serum antibodies against viral haemorrhagic septicaemia virus (VHSV) using recombinant fragments of their N protein. For this purpose, the virus was first isolated from an infected farm. A part of the nucleocapsid (1–505 bp) gene was amplified by RT‐PCR using specific primers. The amplified fragment was ligated to pMALc2x vector and transferred to DH5α strain of Escherichia coli. Then, recombinant plasmids were tested for protein expression in E. coli Rosetta strain. SDS‐PAGE analysis indicated the production of a recombinant protein with an expected molecular weight of 61 KDa. Analysis of trout serum samples from seven previously infected farms and two VHS free farms showed that the designed ELISA method was effective in diagnosing the infected fish. The results revealed that the developed serological assay using designed ELISA based on recombinant protein (N) has the potential to be used in monitoring studies and to determine the prevalence of VHS in rainbow trout farms. The present data allow evaluating the levels of nonneutralizing antibodies without crude virus preparations.     

An online operational alert system for the early detection of shrimp epidemics at the regional level based on real-time production

Diseases are among the greatest threats affecting the sustainability of shrimp aquaculture. In Ecuador, diseases of cultured shrimp have been quickly transmitted from one region to another. Therefore, an early detection system of impending epidemics could serve as an important management tool for the aquaculture sector. We developed a system for the early detection of shrimp epidemics for the largest shrimp zone of Ecuador based on production surveillance. The system, called Epidemiological Alert System and Aquaculture Management (SAEMA), uses a geographical information system (GIS) with an imaginary grid cartography (12,860 ha per grid) dividing the study area. A production and management index is calculated with the harvest data of each pond. A standardized deviation around the historical averages and an alert level is calculated per grid and month. Normal conditions of production and therefore the absence of disease are depicted in green and yellow. While, orange and red colours express a disease warning manifested through suboptimal production levels. As a result, a map of the study area with grid divisions is displayed, with a specific alert colour for each grid where information is available. SAEMA was developed as a Web application (http://www.saema.espol.edu.ec) that enables producers to record data via a worksheet format using any web browser. Instantaneously, the applications perform a calculation of the alert index and provide feedback to the alert levels displayed in an interactive map. A feedback process was initiated in May 2006 with 19 participating shrimp farms. The objective of this research is to develop a platform for an early detection of shrimp epidemics on a regional scale. The detection of an epidemic, expressed as suboptimal production in a specific region, can provide producers from other zones and government authorities to engage in time preventive and control measures in order to reduce the spread of diseases.     

The cost efficiency of trout farms in the Black Sea Region,Turkey

This research measured the cost efficiencies of trout farms and explored determinants of cost inefficiencies in the Black Sea Region, Turkey. Data Envelopment Analysis (DEA) was used to estimate efficiency measures of sample farms. The mean technical, allocative and cost efficiencies for trout farms were measured to be 0.82, 0.83 and 0.68, respectively. Efficiency analysis revealed that inefficient farms would have needed to lower feed and labour costs by 32% to perform as well as other similar, best practice farms in the sample. The decomposition of the technical efficiency measure showed that pure technical inefficiency was the primary cause of technical inefficiency. Research results also suggested that there were positive relationships between cost efficiency and pond tenure, farm ownership, experience of the operators, education level of the operators, contact with extension services, off-farm income and credit availability. Feeding intensity, pond size, and capital intensity had negative effects on cost efficiency. Supplying complete technical packages (feed, credit, etc.) for trout farms may stimulate the adoption of improved technologies. Focusing on trout diseases, water quality, feed production and marketing efficiency in farmers training and extension programs may also help to increase economic efficiency in the research area.     

Longitudinal serological surveys of Atlantic salmon, Salmo salar L., using a rapid immunoperoxidase-based neutralization assay for salmonid alphavirus

Longitudinal serological surveys for salmon pancreas disease virus (SPDV), the causal agent of pancreas disease (PD), were conducted on multiple caged populations of Atlantic salmon, Salmo salar L., on two farms over a 77-week period (farm 1, freshwater and marine stages) and a 36-week period (farm 2, marine stage only), using a microtitre-based virus neutralization (VN) assay. Collected sera were also screened for viraemia with SPDV, and pancreas, heart and muscle tissues were examined for lesions consistent with PD. Outbreaks of PD occurred during the marine phase on both farms, as demonstrated by seroconversion, the isolation of virus and progressive histopathological changes consistent with a PD outbreak. All populations monitored showed a progressive increase in seroprevalence of 90-100%, typically accompanied by rises in geometric mean antibody titres. With the exception of one caged population, which showed a marked biphasic seroprevalence pattern, the seroprevalence figures in the remaining four monitored populations remained high (> or =70%) until the end of the study period. Peak VN titres of > or =1/1280 were detected on both farms. The results provide essential baseline information for the interpretation of SPDV VN serology results, and indicate that this methodology is suited to both the diagnosis and seroepidemiology of SPDV infections.     

Viral co‐infections in farmed Atlantic salmon,Salmo salar L., displaying myocarditis

Several different viruses have been associated with myocarditis‐related diseases in the Atlantic salmon aquaculture industry. In this study, we investigated the presence of PMCV, SAV, PRV and the recently identified Atlantic salmon calicivirus (ASCV), alone and as co‐infections in farmed Atlantic salmon displaying myocarditis. The analyses were performed at the individual level and comprised qPCR and histopathological examination of 397 salmon from 25 farms along the Norwegian coast. The samples were collected in 2009 and 2010, 5–22 months post‐sea transfer. The study documented multiple causes of myocarditis and revealed co‐infections including individual fish infected with all four viruses. There was an overall correlation between lesions characteristic of CMS and PD and the presence of PMCV and SAV, respectively. Although PRV was ubiquitously present, high viral loads were with a few exceptions, correlated with lesions characteristic of HSMI. ASCV did not seem to have any impact on myocardial infection by PMCV, SAV or PRV. qPCR indicated a negative correlation between PMCV and SAV viral loads. Co‐infections result in mixed and atypical pathological changes which pose a challenge for disease diagnostic work.     

Practice observations of cross protection between bovine and porcine herpesviruses]

In many cattle herds in Lower Saxony the serologic IBR/IPV = BHV-1-status is known because since 1988 the bovine herpes virus infection (BHV 1), the infectious rhinotracheitis and pustular vulvovaginitis (IBR/IPV) are being fought. Through extensive investigations in five districts in the Weser-Ems area, it was found that cows infected by bovine herpes virus (BHV 1) are also protected to a high degree against infection by porcine herpes suis virus (SHV 1). An interpretation of the observed cross protection is not yet possible; further research is necessary.