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51.
BACKGROUND: Bombus terrestris L. bumblebees are widely used as commercial pollinators, but they might also be of help in the battle against economically important crop diseases. This alternative control strategy is referred to as pollinator‐and‐vector technology. The present study was designed to investigate the capacity of B. terrestris to fulfil this role in greenhouse strawberry flowers, which were manually inoculated with a major plant pathogen, the grey mould Botrytis cinerea Pers.: Fr. A model microbiological control agent (MCA) product Prestop‐Mix was loaded in a newly developed two‐way bumblebee dispenser, and, in addition, the use of the diluent Maizena‐Plus (corn starch) was tested. RESULTS: Importantly, loading of the MCA caused no adverse effects on bumblebee workers, with no loss of survival or impairment of flight activity of the workers during the 4 week flowering period. Secondly, vectoring of Prestop‐Mix by bumblebees resulted in a higher crop production, as 71% of the flowers developed into healthy red strawberries at picking (preharvest yield) as compared with 54% in the controls. In addition, these strawberries were better protected, as 79% of the picked berries remained free of B. cinerea after a 2 day incubation (post‐harvest yield), while this percentage was only 43% in the control. Overall, the total yield (preharvest × post‐harvest) was 2–2.5 times higher than the total yield in the controls (24%) in plants exposed to bumblebees vectoring Prestop‐Mix. Thirdly, the addition of the diluent Maizena‐Plus to Prestop‐Mix at 1:1 (w/w) resulted in a similar yield to that of Prestop‐Mix used alone, and in no negative effects on the bumblebees, flowers and berries. CONCLUSIONS: This greenhouse study provides strong evidence that B. terrestris bumblebees can vector a MCA to reduce B. cinerea incidence in greenhouse strawberries, resulting in higher yields. Similar yields obtained in the treatments with Prestop‐Mix and Prestop‐Mix + Maizena‐Plus suggest an equally efficient dissemination of the biocontrol agent into the flowers with only half the initial concentration of Prestop‐Mix, which illustrates the importance of the diluent. Copyright © 2011 Society of Chemical Industry 相似文献
52.
Vlaminck L Cnudde V Pieters K Van Den Broeck W Steenhaut M Jacobs P Gasthuys F 《American journal of veterinary research》2008,69(5):604-610
OBJECTIVE: To evaluate the biological behavior of a nonresorbable bone substitute (NRBS) in the alveoli of ponies, compared with tissue quality in naturally healing alveoli, after cheek tooth extraction. ANIMALS: 5 clinically normal ponies. PROCEDURES: In each pony, both maxillary fourth premolars (Triadan 108/208) were repulsed bilaterally during anesthesia. One randomly chosen alveolus was filled with NRBS and isolated from the oral cavity by use of dental impression material and a spring-wire retention device. The other alveolus was occluded in its occlusal third portion with dental impression material. One year after surgery, cylindrical lateromedial biopsy specimens were collected from the apical, middle, and occlusal level of each alveolus. Biopsy samples were evaluated for bone mineral density and bone volume via micro-computed tomography; qualitative histologic characteristics were evaluated via light microscopy. RESULTS: Bone mineral density and bone volume were greater in control alveoli, compared with NRBS-treated alveoli. Control alveoli were characterized by the presence of few mature bone trabeculae and wide spaces containing fat tissue and mesenchymal stroma. In treated alveoli, biocompatibility and osteoconductive properties of the NRBS were excellent; continuous bone formation and bone remodeling were also evident. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the NRBS was integrated well in calcified alveolar tissues in ponies 1 year after maxillary cheek tooth extraction. Further research is necessary to establish the benefits of this NRBS in the development of a dental implant surgical technique in equids. 相似文献
53.
Snoeck V Van den Broeck W De Colvenaer V Verdonck F Goddeeris B Cox E 《Veterinary immunology and immunopathology》2008,124(1-2):29-40
Very few antigens have been described that induce an intestinal immunity when given orally. Our laboratory demonstrated that oral administration of isolated F4 (K88) fimbriae of Escherichia coli to F4-receptor positive (F4R(+)) pigs induces protective mucosal immunity against challenge infection. However, presence of F4-receptors (F4R) on villous enterocytes is a prerequisite for inducing the immune response, as no F4-specific antibody-secreting cells (ASC) can be induced in F4R(-) pigs. In this study, the in vivo binding of isolated F4 fimbriae (F4) to the gut epithelium was examined in F4R(+) and F4R(-) pigs. It was further investigated whether binding of F4 to the F4R results in endocytosis in and translocation across the gut epithelium using microscopy. F4 did not adhere to the intestinal epithelium of F4R(-) pigs, whereas it strongly adhered to the villous epithelium and the follicle-associated epithelium (FAE) of the jejunum and ileum of F4R(+) pigs. Following binding to F4R, F4 was endocytosed by villous enterocytes, follicle-associated enterocytes and M cells. Transcytosis of F4 across the epithelium resulted in the appearance of F4 in the lamina propria and dome region of the jejunal and ileal PP. This is the first study showing transcytosis of fimbriae across the gut epithelium. This receptor-dependent transcytosis can explain the success of F4 fimbriae as oral immunogen for inducing protective immunity in F4R(+) pigs strengthening the importance of receptor-dependent endocytosis and translocation in oral vaccine strategies. Further identification of the receptor responsible for this transport is in progress. 相似文献
54.
In Belgium, the current distribution and abundance of Xylosandrus germanus (Coleoptera, Scolytidae), a relatively new species to the Belgian fauna, is poorly known. Therefore, data on the range and population levels of this ambrosia beetle, on a regional and local scale respectively, are presented. Based on those results, the beetles range is discussed. Among the analysed biotic and abiotic factors that could influence the species settlement and population levels, climatic ones, and temperature in particular, seem to exert a crucial influence. 相似文献
55.
In order to reduce widespread degradation in desertification prone areas, there is an urgent need to understand the mechanisms controlling human-induced degradation processes in semi-arid ecosystems. Southeast Spain is known as one of the most arid regions of Europe, and its landscape is marked by sparsely vegetated degraded hillsides. Large areas of dry cultivation have been abandoned since the early part of the twentieth century, and irrigated cultivation is now expanding rapidly. In this study, modern erosion rates for two mountain ranges belonging to the Betic Cordillera were assessed by direct measurements of the accumulated sediment volumes behind 20 checkdams. The volume of sediment deposited behind the checkdams ranges between 4 and 920 m3, for catchments with a drainage area varying between 1.5 and 317 ha. Our measurements indicate that mean annual catchment-wide erosion rates in these mountain ranges are generally low. The observed erosion rates are well below maximum tolerable annual soil loss rates for the Mediterranean region, as 90% of the catchments have mean annual erosion rates below 2 t ha? 1 y? 1. Our erosion data from 20 small catchments in the Betic range are lower than the results of previous erosion studies in southeast Spain that were conducted in the Neogene intramontane basins. This study deals with erosion rates on thin soils developed on metamorphic rocks, which are not often the subject of study in the Mediterranean region. In the ephemeral stream systems in the Betic range, the spatial pattern of the vegetation cover within the catchment in relation to the concentrated flow lines appears to be crucial. Our data question the direct association of steep, sparsely vegetated hillsides with enhanced soil erosion rates, and suggest that the main erosion problems are currently not located in these steep, sparsely vegetated environments of the Betic mountain ranges. 相似文献
56.
Veerle Mommaerts Guido Sterk Lucien Hoffmann Guy Smagghe 《Pest management science》2009,65(9):949-955
BACKGROUND: This study was undertaken to identify any potential adverse side effects of the use of seven microbiological control agents (MCAs) on the bumblebee, Bombus terrestris L., in the context of combined use in integrated pest management (IPM). AQ10® (Ampelomyces quisqualis), Binab‐T‐vector® (Hypocrea parapilulifera + T. atroviride; 1/1), Prestop‐Mix® (Gliocladium catenulatum J1446), Serenade® (Bacillus subtilis QST713), Trianum‐P® (Trichoderma harzianum T22), Botanigard® (Beauveria bassiana GHA) and Granupom® (Cydia pomonella granulovirus), comprising five biofungicides and two bioinsecticides, were investigated. Bumblebee workers were exposed under laboratory conditions to each MCA at its maximum field recommended concentration (MFRC) via three different routes of exposure: dermal contact and orally via either treated sugar water or pollen. RESULTS: The tested MCAs were found to be safe for workers of B. terrestris, with the exception of Botanigard® and Serenade®. Exposure to Botanigard® via contact at its MFRC caused 92% mortality after 11 weeks, while the 1/10 MFRC killed 46% of exposed workers. For Serenade®, topical contact and oral delivery via sugar water resulted in 88 and 100% worker mortality respectively. With lower concentrations (1/2, 1/5 and 1/10 MFRC) the toxicity decreased, but the effect depended on the route of exposure. In addition to lethal effects, nests were also evaluated for sublethal effects after treatment with the seven MCAs at their respective MFRCs over 11 weeks. In these bioassays, only Botanigard® and Serenade® gave rise to a significant (P < 0.05) decrease in drone production. Sublethal effects on foraging behaviour were also evaluated, and only Botanigard at its MFRC delivered via treated sugar water induced negative effects. CONCLUSION: The results demonstrated that most of the MCAs tested can be considered safe for use in combination with B. terrestris, based on the International Organisation for Biological Control of Noxious Animals and Plants (IOBC) classification. However, some can be harmful, such as the biofungicide Serenade® and the bioinsecticide Botanigard®. Therefore, it is recommended that all should be tested before use in combination with pollinators. In this context, it is also advisable that these MCAs should be evaluated in more realistic field situations for the assessment of potentially deleterious effects on foraging behaviour. Copyright © 2009 Society of Chemical Industry 相似文献
57.
L O Fiems J L De Boever S De Campeneere J M Vanacker 《Archives of Animal Nutrition》2002,56(5):351-359
Daily dry matter intake in young growing double-muscled bulls, fed indoors on grass, was estimated based on forty-four intake data from 28 animals, ageing at least five months and weighing up to 400 kg live weight. Intake was measured during five consecutive days using one of eighteen cuts of grass. Fresh meadow grass (mainly Lolium perenne) was fed ad libitum and two kg dried sugar-beet pulp was offered per animal and per day. Animal live weight averaged 278 +/- 82 kg and mean total daily dry matter intake amounted to 5.05 +/- 1.59 kg or 73.6 +/- 13.7 g per kg metabolic weight, while pulp dry matter intake amounted to 1.49 +/- 0.50 kg per day. Regression analysis showed that animal as well as feed characteristics could explain up to approximately 90% of the variation in daily dry matter intake. The supplementation resulted in an extra daily dry matter intake of 0.68 g per g pulp dry matter. Intake of double-muscled animals was considerably lower than previously reported for non-double-muscled cattle. An extra supplementation of young grazing double-muscled animals could be advised from these findings, while extra protein should also be considered. 相似文献
58.
Oral immunisation of pigs with fimbrial antigens of enterotoxigenic E. coli: an interesting model to study mucosal immune mechanisms 总被引：1，自引：0，他引：1
Cox E Van der Stede Y Verdonck F Snoeck V Van den Broeck W Goddeeris B 《Veterinary immunology and immunopathology》2002,87(3-4):287-290
The intestinal mucosal immune system can discriminate actively between harmful pathogenic agents and harmless food antigens resulting in different immune responses namely IgA production and oral tolerance, respectively. Recently, a pig model has been developed for studying intestinal mucosal immune responses in which F4 fimbrial antigens of enterotoxigenic Escherichia coli (F4 ETEC) are used as oral antigens. A unique feature of this model is that soluble F4 antigens can be administered to pigs which have a receptor for this fimbriae (F4R(+)) on their small intestinal villous enterocytes and pigs which do not have this receptor (F4R(-)). Oral administration of F4 to the F4R(+) pigs results in an intestinal mucosal immune response that completely protects the pigs against a challenge infection. In F4R(-) pigs such an intestinal mucosal immune response does not occur. However, a priming of the systemic immune system can be seen similar to the priming in pigs fed with the same dose of a food antigen, suggesting that F4 in F4R(-) pigs behaves as a food antigen. The fact that different mucosal immune responses can be induced with soluble F4, makes it an interesting model to study mucosal immune mechanisms in the pig. 相似文献
59.
L O Fiems B G Cottyn C V Boucque J M Vanacker F X Buysse 《Archives of Animal Nutrition》1990,40(8):713-721
Effect on nylon-bag digestibility of rolling and steam-flaking as such or followed by grinding through a 1-mm screen was studied in wheat, barley and maize grains. Digestibilities of ground grains were not different, irrespective of rolling or steam-flaking, except flaked and ground barley, which was less digestible than ground barley. Rolled and flaked grains were less digestible than ground grains, except for rolled wheat which was not different from ground wheat. These results suggest that particle size due to grinding is more important than other methods of processing. Dry matter and protein degradabilities of steam-flaked grains were investigated by in sacco technique and compared with unprocessed grains. Dry matter degradability during incubation periods up to 24 h was reduced for steam-flaked wheat and barley, but increased for flaked maize. Protein degradability was lower for flaked grains. 相似文献
60.
Milk urea content (MUC) is used to manage protein nutrition and predict nitrogen excretion of dairy cows. However, MUC might depend on the roughage type offered and hence, for comparable MUC values, different N-excretions might be found. To evaluate this, three diets were compared in a feeding trial with 18 lactating Holstein cows in a Latin square design with as roughages 100% maize silage (treatment 100 MS), 50%/50% maize silage/prewilted grass silage (treatment 50 MS) and 100% prewilted grass silage (treatment 100 PGS). For all treatments, cows were fed to supply 105% of their net energy and digestible protein requirements and to have a daily rumen degraded protein balance (RDPB) intake of 100 g. This was only possible by feeding soybean meal as a protein corrector to 100 MS and 50 MS and by feeding citruspulp as an energy corrector in 100 PGS. The same balanced concentrate was fed to all groups. In a separate trial, N-balance was determined for both 100% rations.In the feeding trial, the MUC of 100 MS (230 mg/l) and 50 MS treatment (214 mg/l) were significantly (P < 0.001) different from that of 100 PGS (171 mg/l). Cows on treatments 50 MS and 100 PGS ingested the same amount of RDPB (71 and 73 g/day), but when fed 100 MS cows ingested −16 g/day. After correction for differences in energy and protein supply, MUC of the 100 MS was 71 mg/l higher than that of 100 PGS.N-balances indicated that total N-excretion (faecal, urinary and milk) was almost identical for both treatments: 392 for 100 MS versus 389 g/day for 100 PGS, as was environmental N-excretion (faecal and urinary): 259 for 100 MS versus 272 g/day for 100 PGS. However, the MUC content for 100 MS was significantly higher: 248 mg/l versus 180 mg/l for 100 PGS. From a correction for differences in energy and protein supply, this difference increased up to 84 mg/l between 100 MS and 100 PGS.These results suggest that MUC is roughage dependent and that a system to predict N-excretion should account for these differences. Therefore the exact mechanism behind the determined roughage influence should be investigated further. 相似文献