仔猪等孢球虫感染的诊断   总被引：3，自引：0，他引：3  

钟伟  张海洪  Jozef Vercrusse 《国外畜牧学(猪与禽)》2003,23(6):47-47

现场诊断 仔猪球虫病常常和猪的其它寄生虫病一样,其危害性常常被低估,因为此病缺乏明显的临床症状,死亡率也很低。球虫病可发生于各种类型的猪场中,甚至发生在卫生条件相当好的猪场中。当发生下列情况时,就应怀疑是否为仔猪球虫病在作祟:  相似文献   

Impact of traditional soil burning (guie) on Planosol properties and land‐use intensification in south‐western Ethiopia          下载免费PDF全文

A. Verdoodt  M. Dumon  J. Deckers  E. Van Ranst 《Soil Use and Management》2015,31(2):330-336

In the Gilgel Gibe catchment in Ethiopia, local farmers intensify land use on Planosols by adjusting a traditional soil burning practice known as guie. The burning practice used to be applied in a cycle of shifting cultivation. However, more recently, farmers burn small plots to make fertile seedbeds for Eucalyptus seedlings in the first year before these trees are transplanted to larger plots. The purpose of this research was to assess the physico‐chemical properties of Planosols that have been subjected to burning over the last 10 yrs and evaluate the contribution of guie to land‐use intensification of these soils. Transect studies and interviews of local farmers, followed by chemical, physical and micromorphological analyses of samples from selected plots were used to compare the soil properties of recently (0–2 yrs) and formerly (3–10 yrs) burnt Planosols with those of unburnt Planosols. The analytical results show that the burning practice improved nutrient availability in the first 2 yrs after guie. Increased amounts of exchangeable aluminium (Al) were reported in the long term. Charge fingerprints illustrate that the nutrient‐buffering capacity of the soil was high shortly after the practice but subsequently decreased with time. Given the population pressure on the formerly extensively used Planosols, it is argued that the current application of guie on small, localized plots for raising Eucalyptus seedlings is well adapted to the local socio‐economic context and promotes land‐use intensification on the Planosols. The increased exchangeable Al content of former Eucalyptus seedbeds merits further in‐depth research into the biophysical sustainability of the burning practice.  相似文献   

Vitamin C Requirements of the Angelfish Pterophylum scalare     

Jozef H.  Blom Konrad  Dabrowski James  Ebeling 《Journal of the World Aquaculture Society》2000,31(1):115-118

Abstract.— Despite a large economical value of the ornamental fish trade, little information is available on the dietary ascorbic acid requirements of these species. Ascorbic acid requirements of fishes of the cichlid family appear to vary widely. Juvenile angelfish, a widely produced ornamental cichlid, were maintained on diets containing graded levels of ascorbyl monophosphate. Liver ascorbic acid concentrations after 96 d of feeding were significantly reduced in groups receiving 120 mg or less ascorbic acid equivalents/kg diet. However, no differences in growth or mortality between groups were found, and no external signs of ascorbic acid deficiency were observed, indicating a high resistance of this species against prolonged ascorbic acid deficiency. Based on the long possible life span of angelfish in the aquarium, we proposed a conservative dietary ascorbic acid requirement of 360 mg/ kg diet, necessary to maintain maximum tissue storage of this vitamin.  相似文献   

Condition of Quercus robur L. along a natural Luvisol microtoposequence on loess in Central Belgium     

R. Van de  Moortel  S. Rampelberg  J. Deckers 《Soil Use and Management》1998,14(3):184-186

Abstract. This research aims to assess how the variability in soil morphology of Luvisols along a microtopographic sequence influences the condition of pedunculate oak ( Quercus robur ). The condition of 205 pedunculate oaks was observed during one growth season and related to morphological soil properties. Results show that the presence of a consolidated argillic B horizon or fragipan in Luvisols, has a negative influence on the condition of Q.robur .  相似文献   

Technological properties and fire performance of medium density fibreboard (MDF) treated with selected polyphosphate-based fire retardants     

George I. Mantanis  Jozef Martinka  Charalampos Lykidis  Libor Ševčík 《Wood material science & engineering》2020,15(5):303-311

ABSTRACT

The objective of the work was to evaluate the efficacy of two new polyphosphate-based fire retardants (FRs) and one commercial product named Siriono^® on the fire performance and physical–mechanical properties of medium density fibreboard (MDF) fabricated in the laboratory from Scots pine (Pinus sylvestris L.) wood. The fibres were treated with aqueous solutions of fire retardants, at 12% loading (dry salt on dry wood), and bonded with a melamine urea formaldehyde (MUF) adhesive. The physical and mechanical properties of panels were assessed using the European standards, whereas their fire performance was evaluated using an in-house method and the Cone calorimeter. In overall, the chemicals added enhanced the fire and smoke properties of the panels to varying degrees. Critical FR parameters such as peak heat release rate (peak HRR), total heat release (THR) and total smoke production (TSP) were significantly improved in the FR-treated panels, as exhibited in cone calorimeter tests. However, the internal bond strength of treated panels largely decreased by the addition of fire retardants, while thickness swell and water absorption negatively affected to a significant extent. In contrast, the formaldehyde release of the panels was considerably decreased at the E1 class level, with the incorporation of the polyphosphate-based additives.  相似文献   

Normal electrocardiographic and echocardiographic (M-mode and two-dimensional) values in Polish Landrace pigs     

Urszula Paslawska  Agnieszka Noszczyk-Nowak  Robert Paslawski  Adrian Janiszewski  Liliana Kiczak  Dorota Zysko  Jozef Nicpon  Ewa A Jankowska  Andrzej Szuba  Piotr Ponikowski 《Acta veterinaria Scandinavica》2014,56(1)

Background

Swine are recognized animal models of human cardiovascular diseases. Normal values of cardiac morphology and function have been published for swine but for smaller number of pigs and not for swine whose weights ranged up 100 kg. In order to improve the value of results of an investigation on cardiac morphology and function in swine when such data are extrapolated to humans, the aim of this study was to document electrocardiographic and echocardiographic measures of cardiac morphology and function in swine. The study comprised 170 single and repeated measurements that were made in 132 healthy domestic swine (Sus domesticus) whose weights ranged between 20-160 kg and were used as controls in three different experiments. All electrocardiographic and echocardiographic measurements in all swine were done under general anaesthesia.

Results

Statistically significant correlations were found between body weight and heart rate (HR), the duration of the P-wave, the duration of the QRS interval, the duration of the QT interval, and the corrected QT ratio (QTc). Since body weight was positively correlated with age, statistically significant correlations were also found between age and HR, the duration of the P-wave, the duration of the QRS interval, the duration of the QT interval, and the QTc. We found that the thickness of the left ventricular wall and the internal diameter of the left ventricle increased with age and body weight. We also found positive trends between body weight and ejection fraction and body weight and fractional shortening. We also found a positive relationship between age, body weight, and the ratio of the left ventricular internal diameter to its wall thickness, as well as the relative left atrial size.

Conclusion

Many electro- and echocardiographic measures of cardiac morphology and function of healthy swine are related to their body weight. When the electro- and echocardiographic measures of domestic swine and humans are compared, the most comparable electrocardiographic values are those that were determined in swine whose body weights are not greater than 70 kg. In contrast, the most comparable echocardiographic measures are those that were determined in swine with a body weight of 40–110 kg.  相似文献   

Effectiveness of stone bunds in controlling soil erosion on cropland in the Tigray Highlands, northern Ethiopia   总被引：4，自引：0，他引：4  

Desta Gebrernichael    J. Nyssen  J. Poesen  J. Deckers  Mitiku Haile  G. Govers  J. Moeyersons 《Soil Use and Management》2005,21(3):287-297

Abstract Use of stone bunds to enhance soil and water conservation was first introduced to Tigray, northern Ethiopia in 1981. This study was designed to examine the factors that control the effectiveness of bunds installed on cropland. Qualitative and quantitative assessments of soil loss and sediment accumulation were conducted on 202 plots at 12 representative sites in Dogu'a Tembien district. Mean annual soil loss from the foot of the bunds due to tillage erosion was estimated at 39kgm⁻¹yr⁻¹ or 20tha⁻¹yr⁻¹, a rate which decreased with increasing age of bund. The assessed mean annual soil loss rate by sheet and rill erosion in the absence of stone bunds is 57tha⁻¹yr⁻¹. The mean measured annual rate of sediment accumulation behind the stone bunds is 119kgm⁻¹yr^−1/sp or 59tha⁻¹yr⁻¹. The measurements show that the introduction of stone bunds to the region has led to a 68% reduction in annual soil loss due to water erosion. This reduction is due to the accumulation of sediment behind the stone bunds, which occurs faster in the early years after construction and decreases as the depression behind the bunds becomes filled with sediment. New stone bunds are particularly effective in trapping sediment in transport, but regular maintenance and increase in height of the bunds is necessary to maintain their effectiveness. The average USLE P factor for stone bunds in the study area is estimated to be 0.32.  相似文献   

Textural properties and their correlation to cell structure in porous food materials     

Sozer N  Dogan H  Kokini JL 《Journal of agricultural and food chemistry》2011,59(5):1498-1507

This paper focuses on understanding the role of structural parameters and starch crystallization on the toughness of cake samples. Accurate mechanical measurements were performed to obtain toughness values, and these were related to structural parameters obtained from image analyses. Three-dimensional skeletons of food samples were generated by using X-ray tomography technique. The structural parameters (cell diameter, cell wall thickness, thickness to radius ratio (t/R), fragmentation index) were obtained after processing of the images with CTan software. The basic hypothesis of the paper is to show that the structural parameter t/R is a determinant for predicting toughness, which is a critical indicator of freshness. Freshness in cakes and other baked products is a leading factor in consumer perception. For this purpose three different cake formulations were stored at 37 and 50 °C. Cycling from these temperatures to lower storage temperatures of 25 and 4 °C was done to accelerate the starch retrogradation rate. Experimental results indicated that there was a strong interrelationship between morphological structure and the mechanical properties with regression coefficients of 0.68 and 0.95. Starch retrogradation, which was followed by X-ray diffractometry, was found to be directly proportional to toughness values, where the percent relative crystallinity increased with storage temperature.  相似文献   

Biocontrol potential of native Trichoderma isolates against root-knot nematodes in West African vegetable production systems     

Antoine Affokpon  Danny L. Coyne  Rufin Dossou Agbèdè  Jozef Coosemans 《Soil biology & biochemistry》2011,43(3):600-608

Seventeen isolates of the free-living soil fungus Trichoderma spp., collected from Meloidogyne spp. infested vegetable fields and infected roots in Benin, were screened for their rhizosphere competence and antagonistic potential against root-knot nematodes, Meloidogyne incognita, in greenhouse pot experiments on tomato. The five isolates expressing greatest reproductive ability and nematode suppression in pots were further assessed in a typical double-cropping system of tomato and carrot in the field in Benin. All seventeen isolates were re-isolated from both soil and roots at eight weeks after application, with no apparent crop growth penalty. In pots, a number of isolates provided significant nematode control compared with untreated controls. Field assessment demonstrated significant inhibition of nematode reproduction, suppression of root galling and an increase of tomato yield compared with the non-fungal control treatments. Trichoderma asperellum T-16 suppressed second stage juvenile (J₂) densities in roots by up to 80%; Trichoderma brevicompactum T-3 suppressed egg production by as much as 86%. Tomato yields were improved by over 30% following the application of these biocontrol agents, especially T. asperellum T-16. Although no significant effects were observed on carrot galling and yield, soil J₂ densities were suppressed in treated plots, by as much as 94% (T. asperellum T-12), compared with the non-fungal controls. This study provides the first information on the potential of West-African Trichoderma spp. isolates for use against root-knot nematodes in vegetable production systems. The results are highly encouraging, demonstrating their strong potential as an alternative and complementary crop protection component.  相似文献   

Impact of land use changes on the hydrological properties of volcanic ash soils in South Ecuador   总被引：3，自引：0，他引：3  

W. Buytaert  J. Deckers  G. Dercon  B. de  Bièvre  J. Poesen  G. Govers 《Soil Use and Management》2002,18(2):94-100

Abstract. The effect of land use on the water retention capacity of Umbric Andosols in south Ecuador was studied. The objective was to acquire a better insight into the hydrological processes of the ecosystem and the role of the soil, in order to assess the impact of changing soil properties due to land use change on the hydrology of the high Andes region. Field data on the water retention capacity at wilting point of Umbric Andosols were collected for both cultivated field conditions and original bush vegetation. The pH in water and in NaF, texture, organic matter content and dry bulk density were measured to show which physicochemical soil characteristics are responsible for the water retention of the Umbric Andosols and for the irreversible loss in water retention due to air drying. Organic matter content appears to be very important and certainly more important than allophane clay content. Water retention of the organic litter layer was calculated to be 16 mm, this would be lost when vegetation was cleared and the land cultivated.  相似文献