Fumonisins affect the intestinal microbial homeostasis in broiler chickens,predisposing to necrotic enteritis     

Gunther Antonissen  Siska Croubels  Frank Pasmans  Richard Ducatelle  Venessa Eeckhaut  Mathias Devreese  Marc Verlinden  Freddy Haesebrouck  Mia Eeckhout  Sarah De Saeger  Birgit Antlinger  Barbara Novak  An Martel  Filip Van Immerseel 《Veterinary research》2015,46(1)

Fumonisins (FBs) are mycotoxins produced by Fusarium fungi. This study aimed to investigate the effect of these feed contaminants on the intestinal morphology and microbiota composition, and to evaluate whether FBs predispose broilers to necrotic enteritis. One-day-old broiler chicks were divided into a group fed a control diet, and a group fed a FBs contaminated diet (18.6 mg FB1+FB2/kg feed). A significant increase in the plasma sphinganine/sphingosine ratio in the FBs-treated group (0.21 ± 0.016) compared to the control (0.14 ± 0.014) indicated disturbance of the sphingolipid biosynthesis. Furthermore, villus height and crypt depth of the ileum was significantly reduced by FBs. Denaturing gradient gel electrophoresis showed a shift in the microbiota composition in the ileum in the FBs group compared to the control. A reduced presence of low-GC containing operational taxonomic units in ileal digesta of birds exposed to FBs was demonstrated, and identified as a reduced abundance of Candidatus Savagella and Lactobaccilus spp. Quantification of total Clostridium perfringens in these ileal samples, previous to experimental infection, using cpa gene (alpha toxin) quantification by qPCR showed an increase in C. perfringens in chickens fed a FBs contaminated diet compared to control (7.5 ± 0.30 versus 6.3 ± 0.24 log10 copies/g intestinal content). After C. perfringens challenge, a higher percentage of birds developed subclinical necrotic enteritis in the group fed a FBs contaminated diet as compared to the control (44.9 ± 2.22% versus 29.8 ± 5.46%).

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0234-8) contains supplementary material, which is available to authorized users.  相似文献   

Composition and structure of balsa (Ochroma pyramidale) wood     

Marc Borrega  Patrik Ahvenainen  Ritva Serimaa  Lorna Gibson 《Wood Science and Technology》2015,49(2):403-420

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Spatially varying temperature trends in a Central California Estuary     

Ricardo T. Lemos  Bruno Sansó  Marc Los Huertos 《Journal of Agricultural, Biological & Environmental Statistics》2007,12(3):379-396

We consider monthly temperature data collected over a period of 16 years at 24 stations in the estuarine wetlands of the Elkhorn Slough watershed, located in the Monterey Bay area in Central California, USA. Our goal is to develop a statistical model in order to separate the seasonal cycle, short-term fluctuations, and long-term trends, while accounting for the spatial variability of these features. In the model, each station has a specific, time-invariant mixture of two seasonal patterns, to encompass the spatial variability of oceanic influence. Likewise, trends are modeled as local mixtures of two patterns, to include the spatial variability of long-term temperature change. Finally, all stations share a common baseline, whose temporal variability is linearly dependent on a variable that summarizes several atmospheric measurements. We use a Bayesian approach with a purposely developed Markov chain Monte Carlo method to explore the posterior distribution of the parameters. We find that the seasonal cycles have changed in time, that neighboring stations can have substantially different behaviors, and that most stations show significant warming trends.  相似文献   

Triazines in the Marne and the Seine Rivers (France) Longitudinal Evolution and Flows     

Garmouma  Mourad  Blanchoud  Hélène  Teil  Marie-Jeanne  Blanchard  Martine  Chevreuil  Marc 《Water, air, and soil pollution》2001,132(1-2):1-17

The transportation pathways of triazines were investigatedfrom their origins onwards, in the Marne and the Seine rivers(France). According to the 1991 survey, the highest total triazine concentration levels (956 ng L^-1) were found in the river Marne: 580 ng L^-1 for atrazine and 200 ng L^-1 for simazine, in relation with agricultural practices.The total triazine levels reached 829 ng L^-1 in the riverSeine. The other triazines remained low, from 5 to 75 ng L^-1. The triazine fluxes were 226 and 404 kg for a 118 d period in the Marne and the Seine rivers, respectively. Out of the treatment period, triazine peaks were related to riverflows with a 48 hr delay between the peak and the top of theflood. After herbicide treatment, peak concentrations wereclosely related with the precipitations. Concerning theriver Marne tributaries, highest atrazine concentrationswere found in June, in those which drained the vineyardarea. In January, the concentrations were higher inperiurban areas underlining their contribution to theherbicide inputs in the rivers. On the whole, the ratio oftriazines transported in the two rivers represented 0.2%of the total amount applicated annually on their catchment basins.  相似文献   

The effects of understory bamboo on broad-scale estimates of giant panda habitat   总被引：1，自引：0，他引：1  

Marc Linderman  Scott Bearer  Yingchun Tan  Jianguo Liu 《Biological conservation》2005,121(3):383-390

Understory vegetation is an important habitat component for many wildlife species. Previous broad-scale studies on biodiversity and wildlife habitat have suffered from a lack of detailed information about understory distribution. Consequently, it is unclear how understory distribution influences the analysis of habitat quantity and spatial distribution. To address this problem, we compared estimates of giant panda (Ailuropoda melanoleuca) habitat with and without understory bamboo. The results show that the spatial distribution of bamboo has a substantial effect on the quantity and spatial arrangement of panda habitat. Total amount of estimated habitat decreased by 29-52% and decreased connectivity was notable after bamboo information was incorporated into the analyses. The decreases in the quantity and quality of panda habitat resulted in a decrease of 41% in the estimated carrying capacity. Our results suggest that it is necessary to incorporate understory vegetation into large-scale wildlife habitat research and management to avoid overestimation of habitat and improve broad-scale analyses of species distributions and biodiversity estimates in general.  相似文献   

pH-dependent interaction of fumonisin B1 with cholesterol: physicochemical and molecular modeling studies at the air-water interface.     

Radhia Mahfoud  Marc Maresca  Maurice Santelli  Annie Pfohl-Leszkowicz  Antoine Puigserver  Jacques Fantini 《Journal of agricultural and food chemistry》2002,50(2):327-331

Langmuir film balance technology was used to study the interaction between the mycotoxin fumonisin B1 (FB1) and cholesterol. FB1 was added in the aqueous subphase underneath a monomolecular film of cholesterol, and the interaction was measured as an increase in the surface pressure of the film. Above pH 9, a strong inhibition of the reaction was observed. Similar results were obtained with the bile salt sodium taurocholate. The FB1-cholesterol complex was reinforced by NaCl but was destabilized by NaF, a salt known to break hydrogen bonds. These data suggest that the molecular association between FB1 and cholesterol involves both hydrophobic interactions and a hydrogen bond between the NH3(+) group of FB1 and the OH group of cholesterol. Molecular mechanics simulations of the FB1-cholesterol complex were consistent with this hypothesis. These data may shed some light on the mechanisms involved in the intestinal absorption of FB1 and its biliary excretion.  相似文献   

生产健康动物的三个营养步骤     

翁善钢 《国外畜牧学(猪与禽)》2013,33(4):25-28

用极少的抗生素饲养出健康的动物——这是欧洲畜牧业面临的主要挑战。消费者、零售商和政府管理部门都清楚地表达出这一信息。在一些国家,控制措施早已实施;而在其他一些国家,这些讨论才刚刚开始。总体来说,很明显,在可预见的未来,在整个欧洲范围内利用受控的低水平抗生素进行可持续的畜牧业生产将是强制性的。  相似文献   

The effects of drought on the water use, fruit development and oil yield from young olive trees     

Marc Greven  Sue Neal  Steve Green  Bartolomeo Dichio  Brent Clothier 《Agricultural Water Management》2009,96(11):1525-1531

In Marlborough, New Zealand, olives are becoming an important crop alongside grapes. However, despite olives being drought resistant, they are generally planted on the poorer free-draining soils. Also, with the strong increase in cropping area, the demand for irrigation water has increased dramatically. In this research, we investigate the impact of short-term water stress on plant physiological processes, crop yield and oil quality in Marlborough, New Zealand. For that purpose, during the dry summer of 2000–2001, two trees were kept without irrigation for 64 days while two neighbouring trees were irrigated following standard practice. The trees were measured for transpiration (E), leaf and stem water potential (Ψ_L and Ψ_S), every other day, from dawn to dusk for three weeks from just before irrigation was started up again. All four trees were wired up for measuring stem sap flow (T) which was recorded hourly and a basic meteorological station provided weather data. Fruit and shoot development was measured weekly. It was found that under the short period of dry conditions with soil moisture (() dropping to <5%, olive trees kept functioning at a very low level with Ψ_L and Ψ_S reduced from −1 to <−4.0 MPa (T) reduced from 20 to 5 mm/h and (E) reduced from 1.5 to 1.0 mmol m⁻² s⁻¹. Within 10 days of restarting irrigation all these parameters were back to pre-drought levels. Both fruit and shoot growth came to a standstill within a week after drought was induced. During the first few days after re-watering, a high variability in Ψ_L was found between leaves from the same trees. This variability disappeared after six days. Shoot growth did not recover after re-watering but fruit growth rate, became the same as for continuously irrigated trees within days, but fruit size did not manage to recover before harvest. Yield from the dry trees was low because berry and pit weight were reduced by almost 50% at harvest, had a lower oil and percentage and were lower in phenolics. Stem sap flow was found to give a very good continuous measurement for the hydration status of the olive trees.  相似文献   

Double dose efficiency of the yellow rust resistance gene Yr17 in bread wheat lines     

Olivier Coriton  Joseph Jahier  Marc Leconte  Virginie Huteau  Gwenn Trotoux  Françoise Dedryver  Claude de-Vallavieille-Pope 《Plant Breeding》2020,139(2):263-271

Yellow rust, caused by Puccinia striiformis f. sp. tritici, is one of the most severe wheat disease worldwide. Crop losses have ranged from 10% to 70% and up to 100% in extreme conditions. Eighty-two resistance genes, designated Yr, have been identified. Among them, Yr17 derived from Aegilops ventricosa and located on chromosome 2A has been widely used in wheat breeding. However, it had been overcome already. Through recombination of the Ae. ventricosa Yr17-carrying 6N^v chromosome with 2D of wheat, we introduced Yr17 onto chromosome 2D. Then, lines carrying Yr17 on both 2A and 2D were generated. Seedlings of the latter, as well as those carrying a single dose of Yr17 either on 2A or on 2D, were inoculated with virulent or avirulent strains on wheat seedlings. The different genotypes were fully susceptible for the two pathotypes that are virulent on Yr17. In the case of avirulent pathotypes, the Yr17 double dose lines were fully resistant, while those with the Yr17 gene only on either 2A or 2D had intermediate resistance reactions towards one or the other or both pathotypes.  相似文献   

Creating the data basis to adapt agricultural decision support tools to new environments,land management and climate change—A case study of the RiceAdvice App     

Marc Cotter  Folkard Asch  Bayuh Belay Abera  Boshuwenda Andre Chuma  Kalimuthu Senthilkumar  Arisoa Rajaona  Ando Razafindrazaka  Kazuki Saito  Sabine Stuerz 《Journal of Agronomy and Crop Science》2020,206(4):423-432

Increasing demand for land to ensure human food security in the future has already impelled agricultural production into marginal areas. The environmental conditions found there have a more pronounced impact on agricultural productivity than in the systems used so far under favourable conditions. In addition to this challenge, climate change is expected to increase the unreliability of weather conditions (through increased variability and occurrence of extremes) for farmers considerably. This unreliability is even more serious in developing countries’ farming system where food security is vulnerable. Current efforts in digitalization offer great possibilities to improve farmers` decision-making processes. A wide range of online tools and smartphone applications is available to support both agricultural extension services and smallholder farmers alike. These apps are often parameterized and validated to certain environments and are troubled when applied to new geographical locations and different environmental conditions. We have conducted field trials to demonstrate potential methods to close knowledge gaps in the data background for one of these apps, RiceAdvice, concerning three key aspects: shifting of cropping calendar, adjustment of fertilizer management and genotype selection. Sites in Ethiopia, Madagascar and Rwanda were selected to represent altitudinal gradients, with overlapping elevations reflecting differences in temperature to enable cross-country comparisons. Planting dates were distributed throughout three calendar years, with continuous iterative planting dates taking place in Madagascar, in- and off-season planting dates in Rwanda with different fertilizer applications, and one planting date during each rainy season in Ethiopia with different management options. With these trials, we have been able to identify key data sets needed for the adaptation of agricultural decision support tools to new environments. These include the assessment of climatic constraints on innovations to cropping calendars (e.g. double cropping), informed selection of alternative varieties able to complete crucial parts of their phenological development to avoid temperature-related stress inducing, for example spikelet sterility in rice in late development stages and the effectivity of potential innovations in fertilizer management strategies.  相似文献