Laboratory diagnosis and disease occurrence in the current African swine fever eradication program in Spain, 1989–1991     

Steen Bech-Nielsen  Maria Louisa Arias  Jesus Panadero  Jose M. Escribano  Concepcion Gomez-Tejedor  Q. Perez Bonilla  J. M. Sanchez-Vizcaino 《Preventive veterinary medicine》1993,17(3-4):225-234

The purpose of this study was to determine the rate of decline and geographical distribution by municipality of clinical and subclinical African swine fever (ASF) in the affected areas of Spain. A second aim was to evaluate the performance of diagnostic tests in the Spanish ASF eradication program. Clinical outbreaks were confirmed using both the direct and indirect immunofluorescence test (and if both were negative, by the hemabsorption test). The serological status of swine was determined by an enzyme-linked immunosorbent assay (ELISA) and suspect serum samples were confirmed by the immunoblot assay.

The number of clinical outbreaks (herds) of ASF for 1989, 1990 and 1991 was 170, 347 and 207, respectively. The numbers of municipalities within each affected province experiencing acute outbreaks for the same time periods were 49, 69 and 48, respectively. Serologically diagnosed animals positive for ASF were 1.1% of animals tested in 1989, 0.5% in 1990 and 0.8% in 1991. The corresponding positive predictive values of the standard ELISA test used were 99.0, 97.9 and 98.8, respectively. Similarly, the number of municipalities within each affected province experiencing serologically positive subclinically infected animals was 269, 178 and 147 for each of the years 1989, 1990 and 1991, respectively.  相似文献   

Early interspecific dynamics,dry matter production and nitrogen use in Kernza (Thinopyrum intermedium) – alfalfa (Medicago sativa L.) mixed intercropping     

Shoujiao Li  Ana Barreiro  Erik Steen Jensen  Yingjun Zhang 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2020,70(2):165-175

ABSTRACT

The global interest in growing perennial grain crops such as intermediate wheatgrass (Thinopyrum intermedium) (Kernza) for production of food and feed is increasing. Intercropping Kernza with legumes may be a sustainable way of supplying nitrogen to soil and associated intercrop. We determined the competitive interactions between intercropped Kernza (K) and alfalfa (Medicago sativa L.) (A) under three inorganic nitrogen (N) rates N0, N1, N2 (0, 200, 400 kg ha^?1) and five species relative frequencies (SRF) (100%K:0%A, 75%K:25%A, 50%K:50%A, 25%K:75%A and 0% K:100%A) in mixed intercrops (MI) in a greenhouse pot experiment. After 11 weeks of growth. Kernza dry matter yield (DM) and N accumulated (NACC) were low, but alfalfa DM and NACC high at 0 kg N ha^?1. 200 and 400 kg N ha^?1 fertiliser application increased the competitive ability (CA) of Kernza and reduced the CA of alfalfa. SRF had large impacts on alfalfa DM, NACC and NFIX only at 0 kg N ha^?1 fertiliser, and insignificant impacts on Kernza at all N fertiliser levels, indicating that adjustment of SRF may not be an effective way to modulate the interspecific competition of Kernza. Further research on the other factors that influence the interspecific competition are warranted.  相似文献   

Indigenous sheep breeds in Brazil: potential role for contributing to the sustainability of production systems     

Edson Luis de Azambuja Ribeiro  Eliel González-García 《Tropical animal health and production》2016,48(7):1305-1313

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Production of yarrow (Achillea millefolium L.) in Norway: essential oil content and quality     

Rohloff J  Skagen EB  Steen AH  Iversen TH 《Journal of agricultural and food chemistry》2000,48(12):6205-6209

In 1996, the production of Achillea millefolium L. at different locations in Norway was investigated with regard to the developmental stage. The oil content differed greatly between the vegetative stage (0.13%) and the stage of full bloom (0.34%). Changes in the composition of yarrow essential oil were found to be related to maturation of the plant, with increasing amounts of monoterpenes in relation to the sesquiterpene. However, a clear trend could be detected only for the monoterpenic compounds with increasing levels of alpha- and beta-pinene and alpha-thujone and decreasing levels of sabinene, borneol, and bornyl acetate. Previously reported as major compounds, chamazulene and germacrene D could be found only in insignificant amounts. A solid-phase microextraction (SPME) procedure was applied for screening of the terpenic composition. Sesquiterpenic compounds such as beta-bisabolene, alpha-bisabolol, and delta-cadinene were detected in substantial amounts by SPME in contrast to the steam-distilled samples.  相似文献   

CORRECTION OF ANGULAR DEFORMITY BY ASYMMETRIC PHYSEAL GROWTH AND BONE REMODELLING     

Terje O.  Fjeld  DVM  Harald  Steen  MD 《Veterinary radiology & ultrasound》1986,27(2):58-64

Angular deformities of 25 or 37 degrees valgus were created by transverse wedge osteotomies in the diaphysis of the radius in 3-month-old Cocker Spaniels. Spontaneous correction was judged from radiographs until skeletal maturity. The magnitude of correction was estimated, using the opposite normal leg as a control. Asymmetrical physeal growth corrected the induced angulation between the proximal and distal radial joint plane surfaces (joint plane angle). The average correction of the joint plane angle was 80% in the 25 degree group, and 72% in the 37 degree group. Bone remodeling of the radial shaft corrected the induced diaphyseal angulation by 50% in both groups during the study.  相似文献   

Herd diagnosis of low pathogen diarrhoea in growing pigs – a pilot study     

Ken Steen Pedersen  Markku Johansen  ?ystein Angen  Sven Erik Jorsal  Jens Peter Nielsen  Tim K Jensen  Roberto Guedes  Marie St?hl  Poul B?kbo 《Irish veterinary journal》2014,67(1)

Background

The major indication for antibiotic use in Danish pigs is treatment of intestinal diseases post weaning. Clinical decisions on antibiotic batch medication are often based on inspection of diarrhoeic pools on the pen floor. In some of these treated diarrhoea outbreaks, intestinal pathogens can only be demonstrated in a small number of pigs within the treated group (low pathogen diarrhoea). Termination of antibiotic batch medication in herds suffering from such diarrhoea could potentially reduce the consumption of antibiotics in the pig industry. The objective of the present pilot study was to suggest criteria for herd diagnosis of low pathogen diarrhoea in growing pigs.Data previously collected from 20 Danish herds were used to create a case series of clinical diarrhoea outbreaks normally subjected to antibiotic treatment. In the present study, these diarrhoea outbreaks were classified as low pathogen (<15% of the pigs having bacterial intestinal disease) (n =5 outbreaks) or high pathogen (≥15% of the pigs having bacterial intestinal disease) (n =15 outbreaks). Based on the case series, different diagnostic procedures were explored, and criteria for herd diagnosis of low pathogen diarrhoea were suggested. The effect of sampling variation was explored by simulation.

Results

The diagnostic procedure with the highest combined herd-level sensitivity and specificity was qPCR testing of a pooled sample containing 20 randomly selected faecal samples. The criteria for a positive test result (high pathogen diarrhoea outbreak) were an average of 1.5 diarrhoeic faecal pools on the floor of each pen in the room under investigation and a pathogenic bacterial load ≥35,000 per gram in the faecal pool tested by qPCR. The bacterial load was the sum of Lawsonia intracellularis, Brachyspira pilosicoli and Escherichia coli F4 and F18 bacteria per gram faeces. The herd-diagnostic performance was (herd-level) diagnostic sensitivity =0.99, diagnostic specificity =0.80, positive predictive value =0.94 and negative predictive value =0.96.

Conclusions

The pilot study suggests criteria for herd diagnosis of low pathogen diarrhoea in growing pigs. The suggested criteria should now be evaluated, and the effect of terminating antibiotic batch medication in herds identified as suffering from low pathogen diarrhoea should be explored.

Electronic supplementary material

The online version of this article (doi:10.1186/2046-0481-67-24) contains supplementary material, which is available to authorized users.  相似文献   

Error propagation in stock-difference and gain–loss estimates of a forest biomass carbon balance     

Steen Magnussen  Michael Köhl  Konstantin Olschofsky 《European Journal of Forest Research》2014,133(6):1137-1155

According to the United Nations International Panel on Climate Change good practice guidance, an annual forest biomass carbon balance (AFCB) can be estimated by either the stock-difference (SD) or the gain–loss (GL) method. An AFCB should be accompanied by an analysis and estimation of uncertainty (EU). EUs are to be practicable and supported by sound statistical methods. Sampling and model errors both contribute to an EU. As sample size increases, the sampling error decreases but not the error due to errors in model parameters. Uncertainty in GL AFCB estimates is dominated by model-parameter errors. This study details the delta technique for obtaining an EU with the SD and the GL method applicable to the carbon in aboveground forest biomass. We employ a Brownian bridge process to annualize the uncertainty in SD AFCBs. A blend of actual and simulated data from three successive inventories are used to demonstrate the application of the delta technique to SD- and GL-derived AFCBs during the years covered by the three inventories (SD) and rescaled national wood volume harvest statistics (GL). Examples are limited to carbon in live trees with a stem diameter of 7 cm or greater. We confirm that a large contribution to the uncertainty in an AFCB comes from models used to estimate biomass. Application of the delta technique to summary statistics can significantly underestimate uncertainty as some sources of uncertainty cannot be quantified from the available information. We discuss limitations and problems with the Monte Carlo technique for quantifying uncertainty in an AFCB.  相似文献   

Benefit-cost analysis of the current African swine fever eradication program in Spain and of an accelerated program     

Steen Bech-Nielsen  Q. Perez Bonilla  J. M. Sanchez-Vizcaino 《Preventive veterinary medicine》1993,17(3-4):235-249

We predicted the rate of spread and economic losses due to African swine fever (ASF) infections in Spanish swine for a 20 year period using current epidemiological data. Two possibilities for eradication were examined: continuation of the eradication program presently in use, assuming continued funding at present levels, and an accelerated eradication program using more frequent testing to identify seropositive carrier animals. Both programs theoretically would result in the eradication of African swine fever. The calculated benefit-cost ratios were 1.23 and 1.47 respectively. A reduction in current yearly funding would result in a benefit-cost ratio of 0.97, making the program unprofitable according to our model.

The projected year for the eradication of outbreaks is 1996 using provinces as units in the model. Similarly, the projected year for the eradication of seropositive animals is 2001.  相似文献   

Nasal tumor in a fallow deer (Dama dama L). A case report     

Margaretha Steen  Claes Rehbinder  Torsten Mrner 《Acta veterinaria Scandinavica》1985,26(4):461-465

A nasal, so called ethmoidal, tumor from a fallow deer is described. It appears to be the first reported case of that species. The etiology is discussed.  相似文献   

Use of in-growth soil cores in mesh bags for studies of relations between soil compaction and root growth     

Eliel Steen  Inge Hkansson 《Soil & Tillage Research》1987,10(4)

Using in-growth soil cores in cylindrical mesh bags, the effects of 3 soil compaction treatments on growth of crop roots were studied in a sandy soil. The bags were inserted after crop emergence in holes (70 mm diameter; 60 cm depth) augered in the soil in crop row interspaces. In 1984 (with rapessed), at all sampling dates, root biomass in the inserted cores decreased with increased compaction of the plough layer (0–25 cm) as well as the subsoil (25–60 cm). Root biomass in the subsoil was low. In 1985 (with wheat), the effects of compaction in the subsoil were similar, although root biomass was greater than in 1984. However, in the plough layer there were significant differences in root biomass on only one sampling date. The mesh bag technique should be a useful complement to other field methods in studies of relations between physical soil characteristics or tillage treatments and root growth.  相似文献