The efficacy of mesenteric lymph node biopsy in the eradication of paratuberculosis from an infected dairy farm   总被引：2，自引：0，他引：2  

G Benedictus  J Haagsma 《The Veterinary quarterly》1986,8(1):5-11

Lymph node biopsy was performed on animals older than nine months on a dairy farm which carried 223 animals and was severely affected by paratuberculosis. Biopsies were examined histologically and bacteriologically for the presence of M. paratuberculosis infection. In this way paratuberculosis infection was diagnosed in 29 animals, in which other diagnostic methods (serum complement fixation test, intradermal johnin test and microscopic examination of the faeces) produced negative results. The value of lymph node biopsy is the early detection of infected animals. In the two years after the biopsies, no further cases of clinical paratuberculosis were detected on the affected farm, although infection with M. paratuberculosis persisted.  相似文献   

Paratuberculosis: eradication, control and diagnostic methods     

Benedictus G  Kalis CJ 《Acta veterinaria Scandinavica》2003,44(3-4):231-241

At the beginning of the twentieth century, the dairy industry and cattle breeding organisations initiated a programme to control infectious diseases by means of a complex system of rewards and penalties. The history of programmes to control paratuberculosis in sheep, goats, and cattle in various countries is described. The vaccination of young animals (especially goats and sheep) seems to be an effective measure in the prevention of clinical paratuberculosis, although changes in management and hygiene practices are also important. A control programme for infectious cattle diseases has a number of phases (a life cycle) and different components. Two components are essential for success, namely, open and regular communication with farmers, veterinary practitioners, and other people involved, and a good registration and identification system for cattle, herds, and veterinary practitioners. The principles and different levels of control of paratuberculosis are discussed. The Dutch paratuberculosis programme is divided in two parts: an intensive programme based on test and cull and an extensive programme based on education. The intensive programme has ten herd status levels: 5 to 10 for non?suspect herds and 1 to 4 for infected herds or herds of unknown status. The higher the status, the greater the chance that a herd is free of paratuberculosis. An outline is given of the Dutch paratuberculosis programme. Diagnostic methods are summarised. Future developments regarding vaccination and control or acceptance of paratuberculosis are discussed.  相似文献   

Probability of and risk factors for introduction of infectious diseases into Dutch SPF dairy farms: a cohort study   总被引：1，自引：0，他引：1  

van Schaik G  Schukken YH  Nielen M  Dijkhuizen AA  Barkema HW  Benedictus G 《Preventive veterinary medicine》2002,54(3):279-289

A 2-year cohort study was conducted to investigate the probability of disease introduction into Dutch dairy farms. The farms were tested regularly for diseases and were visited biannually to collect management data. Ninety-five specific pathogen-free (SPF) dairy farms were selected from a database of bovine herpesvirus type 1 (BHV1)-free farms to study the probability of, and risk factors for, introduction of BHV1, bovine viral diarrhoea virus (BVDV), Salmonella enterica subsp. enterica serotype Dublin (S. dublin), and Leptospira interrogans serovar hardjo (L. hardjo).Although most of the 95 SPF farms had a low risk on introduction of infectious diseases, one disease was introduced into 12 farms and two diseases were introduced into one farm. Three farms experienced an outbreak of BHV1, one farm an outbreak of L. hardjo, two farms BVDV, six farms S. dublin, and one farm both BHV1 and S. dublin. The total incidence rate was 0.09 (0.06-0.12) per herd-year at risk. The results suggest that the "non-outbreak" farms were significantly more closed than the "outbreak" farms. Direct animal contacts with other cattle should be avoided and professional visitors should be instructed to wear protective clothing before handling cattle.  相似文献   

Adaptive conjoint analysis to determine perceived risk factors of farmers, veterinarians and AI technicians for introduction of BHV1 to dairy farms     

Gerdien van Schaik  Aalt A. Dijkhuizen  Ruud B. M. Huirne  Geert Benedictus 《Preventive veterinary medicine》1998,37(1-4):101-112

A study was carried out to determine the possibility of a more-closed farming system for (Dutch) dairy farms. The objective of the study was to provide effective and economically profitable management advice for improving the animal-health status of farms. Management measures will only be successfully applied if supported by farmers and their advisors (such as veterinarians). Therefore, the perception of farmers and advisors of the importance of various risk factors for the introduction of diseases to a farm was determined by using bovine herpes virus type 1 (BHV1) as an example.

As part of the study, an evening-long workshop was organized and run thrice. In total, 49 farmers, veterinarians and AI technicians participated in these workshops. The computerized questionnaire technique was based on adaptive conjoint analysis (ACA). ACA has the advantage that participants can work with a large number of risk factors in a relatively short period of time. Another advantage of ACA (compared with standard questionnaires) is that the answers from each participant can be checked with regard to consistency with respect to the importance assigned to them. Data from participants with inconsistent responses can be excluded from further analyses. The results of the ACA interview were compared with the risk factors reported in the literature as being associated with BHV1 status (e.g. purchase of cattle, participation in cattle shows) and with farmers' actual management to prevent the introduction of diseases.

The workshop participants were all operating in the dairy sector and they seemed well aware of the risk of direct animal contacts for the introduction of BHV1. Farmers thought visitors to be more risky than did AI technicians and (especially) veterinarians. Farmers who purchased cattle or participated in cattle shows were of the opinion that the risks of direct animal contacts were more important than did farmers who were not involved in those practices. Farmers whose farms were BHV1-positive (and participated in cattle shows more often) thought the risk of participation smaller than did farmers with BHV1-negative farms.  相似文献   

三丁酸甘油酯能促进仔猪健康的肠道,使仔猪快乐     

翁善钢 《国外畜牧学(猪与禽)》2015,(1)

丁酸已被证明对动物肠道健康有益,能够提高仔猪的消化率。由于该化合物有恶臭味,因此已采用不少措施来克服这一问题,如包被技术。那么,以三丁酸甘油酯形式使用又会呈现出什么情况呢?  相似文献   

Electrical stunning followed by decapitation or chilling of African catfish (Clarias gariepinus): assessment of behavioural and neural parameters and product quality   总被引：1，自引：0，他引：1  

Bert Lambooij  Karen Kloosterboer  Marien A Gerritzen  Geert André  Martine Veldman  & Hans Van De Vis 《Aquaculture Research》2006,37(1):61-70

The objective of this study was to assess neural and behavioural responses in farmed African catfish (Clarias gariepinus) upon electrical stunning in combination with decapitation or chilling. To assess the possibility of scaling up one or both experimental methods, two trials were performed in an experimental setting. The product quality of the collected samples was compared with the currently applied industrial method: live chilling. After electrical stunning in combination with decapitation, the fish showed spikes alternated with theta and delta waves on the EEG, followed by minimal brain activity after 20±10 s. The same traces on the EEGs were observed after electrical stunning in combination with chilling. Here, minimal brain activity occurred after 22±11 s. Within a confidence level of 95%, the percentage of African catfish that was effectively stunned after administration of an electrical current of 1.5 A dm⁻², 300 V (50 Hz a.c.), followed by decapitation or chilling was above 91%. The analysis yield and evolution of liquid loss showed significant (P<0.05) differences among the batches, which could be explained by the stunning method used. The course values of the pH in the different batches were significantly (P<0.05) dependent on the stunning method, sex and location (visceral or skin side). It is concluded that African catfish can be stunned effectively using electrical stunning in a water tank, followed by decapitation or chilling in ice. Dutch commercial processors prefer to combine electrical stunning with chilling in flake ice in a rotating tumbler, as the outer slime layer is then removed, which facilitates further processing.  相似文献   

Avian H5N1 influenza in cats     

Kuiken T  Rimmelzwaan G  van Riel D  van Amerongen G  Baars M  Fouchier R  Osterhaus A 《Science (New York, N.Y.)》2004,306(5694):241

During the 2003 to 2004 outbreak of avian influenza A (H5N1) virus in Asia, there were anecdotal reports of fatal infection in domestic cats, although this species is considered resistant to influenza. We experimentally inoculated cats with H5N1 virus intratracheally and by feeding them virus-infected chickens. The cats excreted virus, developed severe diffuse alveolar damage, and transmitted virus to sentinel cats. These results show that domestic cats are at risk of disease or death from H5N1 virus, can be infected by horizontal transmission, and may play a role in the epidemiology of this virus.  相似文献   

Non-linearity and behavior     

van Geert P 《Science (New York, N.Y.)》1994,265(5174):977-978

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Chromosome segregation errors as a cause of DNA damage and structural chromosome aberrations     

Janssen A  van der Burg M  Szuhai K  Kops GJ  Medema RH 《Science (New York, N.Y.)》2011,333(6051):1895-1898

Various types of chromosomal aberrations, including numerical (aneuploidy) and structural (e.g., translocations, deletions), are commonly found in human tumors and are linked to tumorigenesis. Aneuploidy is a direct consequence of chromosome segregation errors in mitosis, whereas structural aberrations are caused by improperly repaired DNA breaks. Here, we demonstrate that chromosome segregation errors can also result in structural chromosome aberrations. Chromosomes that missegregate are frequently damaged during cytokinesis, triggering a DNA double-strand break response in the respective daughter cells involving ATM, Chk2, and p53. We show that these double-strand breaks can lead to unbalanced translocations in the daughter cells. Our data show that segregation errors can cause translocations and provide insights into the role of whole-chromosome instability in tumorigenesis.  相似文献   

A semi-empirical model to assess uncertainty of spatial patterns of erosion   总被引：3，自引：0，他引：3  

Olga Vigiak  Geert Sterk  Renata J. Romanowicz  Keith J. Beven 《CATENA》2006,66(3):198-210

Distributed erosion models are potentially good tools for locating soil sediment sources and guiding efficient Soil and Water Conservation (SWC) planning, but the uncertainty of model predictions may be high. In this study, the distribution of erosion within a catchment was predicted with a semi-empirical erosion model that combined a semi-distributed hydrological model with the Morgan, Morgan and Finney (MMF) empirical erosion model. The model was tested in a small catchment of the West Usambara Mountains (Kwalei catchment, Tanzania). Soil detachability rates measured in splash cups (0.48–1.16 g J^− 1) were close to model simulations (0.30–0.35 g J^− 1). Net erosion rates measured in Gerlach troughs (0.01–1.05 kg m^− 2 per event) were used to calibrate the sediment transport capacity of overland flow. Uncertainties of model simulations due to parameterisation of overland flow sediment transport capacity were assessed with the Generalized Likelihood Uncertainty Estimation (GLUE) methodology. The quality of the spatial predictions was assessed by comparing the simulated erosion pattern with the field-observed erosion pattern, measuring the agreement with the weighted Kappa coefficient of the contingency table. Behavioural parameter sets (weighted Kappa > 0.50) were those with short reinfiltration length (< 1.5 m) and ratio of overland flow power α to local topography power γ close to 0.5. In the dynamic Hortonian hydrologic regime and the dissected terrain of Kwalei catchment, topography controlled the distribution of erosion more than overland flow. Simulated erosion rates varied from − 4 to + 2 kg m^− 2 per season. The model simulated correctly around 75% of erosion pattern. The uncertainty of model predictions due to sediment transport capacity was high; around 10% of the fields were attributed to either slight or severe erosion. The difficult characterisation of catchment-scale effective sediment transport capacity parameters poses a major limit to distributed erosion modelling predicting capabilities.  相似文献