Bacteremia associated with naturally occuring acute coliform mastitis in dairy cows     

Wenz JR  Barrington GM  Garry FB  McSweeney KD  Dinsmore RP  Goodell G  Callan RJ 《Journal of the American Veterinary Medical Association》2001,219(7):976-981

OBJECTIVE: To determine the incidence of bacteremia in dairy cows with naturally occurring acute coliform mastitis (ACM) with a wide range of disease severity. DESIGN: Cohort study. ANIMALS: 144 dairy cows with ACM from 6 herds. PROCEDURE: Cows were examined at time of identification of ACM (time 0) and classified as having mild, moderate, or severe mastitis on the basis of rectal temperature, hydration status, rumen contraction rate, and attitude. Cows were reexamined at 24 or 48 hours. Bacteriologic culturing of milk and blood (30 ml), CBC, and serum biochemical analysis were performed at each time point. Appropriate samples were obtained at a single point from herdmates without mastitis (controls) that were closely matched for lactation number and days since parturition. Blood culture results were compared among severity groups and controls by use of chi2 tests, as was outcome of an ACM episode for cows grouped by blood bacterial isolates. RESULTS: Bacteria were isolated from 52 blood samples from 46 of 144 (32%) cows with ACM, which was significantly more than control cows (11/156; 7.1%). Group-1 isolates (Escherichia coli, Pasteurella multocida, Mannheimia haemolytica, Klebsiella pneumoniae, Enterobacter agglomerans, and Salmonella enterica serotype Typhimurium) were identified in 20 of 144 (14%) cows with ACM and 0 of 156 control cows. Group-1 isolates were identified in 4.3, 9.1, and 42% of cows classified as having mild, moderate, and severe ACM, respectively. Escherichia coli and K pneumoniae milk and blood isolates obtained from the same cow were of the same genotype. Bacillus spp were identified in 21 of 144 (15%) cows with ACM, which was significantly more than control cows (3/156; 1.9%). Thirty-five percent of cows with a group-1 isolate died during the mastitis episode. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that bacteremia develops in a substantial proportion of cows with ACM. Classification of severity of disease is important for establishment of effective treatment protocols; parenteral antimicrobial treatment may be indicated in cows with ACM.  相似文献   

Growth patterns for three generations of an intercross between red junglefowl and chickens selected for low body weight          下载免费PDF全文

Dez‐Ann Antoinette Therese Sutherland  Christa Ferst Honaker  Ben Dorshorst  Leif Andersson  I. Lehr Brisbin Jr  Paul B. Siegel 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2018,135(4):300-310

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Multifunctionality of floodplain landscapes: relating management options to ecosystem services     

Stefan Schindler  Zita Sebesvari  Christian Damm  Katrin Euller  Volker Mauerhofer  Anna Schneidergruber  Marianna Biró  Franz Essl  Róbert Kanka  Sophie G. Lauwaars  Christiane Schulz-Zunkel  Theo van der Sluis  Michaela Kropik  Viktor Gasso  Andreas Krug  Martin T. Pusch  Klaus Peter Zulka  Werner Lazowski  Christa Hainz-Renetzeder  Klaus Henle  Thomas Wrbka 《Landscape Ecology》2014,29(2):229-244

The concept of green infrastructure has been recently taken up by the European Commission for ensuring the provision of ecosystem services (ESS). It aims at the supply of multiple ESS in a given landscape, however, the effects of a full suite of management options on multiple ESS and landscape multifunctionality have rarely been assessed. In this paper we use European floodplain landscapes as example to develop an expert based qualitative conceptual model for the assessment of impacts of landscape scale interventions on multifunctionality. European floodplain landscapes are particularly useful for such approach as they originally provided a high variety and quantity of ESS that has declined due to the strong human impact these landscapes have experienced. We provide an overview of the effects of floodplain management options on landscape multifunctionality by assessing the effects of 38 floodplain management interventions on 21 relevant ESS, as well as on overall ESS supply. We found that restoration and rehabilitation consistently increased the multifunctionality of the landscape by enhancing supply of provisioning, regulation/maintenance, and cultural services. In contrast, conventional technical regulation measures and interventions related to extraction, infrastructure and intensive land use cause decrease in multifunctionality and negative effects for the supply of all three aspects of ESS. The overview of the effects of interventions shall provide guidance for decision makers at multiple governance levels. The presented conceptual model could be effectively applied for other landscapes that have potential for a supply of a high diversity of ESS.  相似文献   

Performance and genetic analysis of coast redwood cultivars for afforestation of converted grassland in California     

Morrison  William M.  Armstrong  Andrew D.  Webb  Lynn A.  Dagley  Christa M.  Cahill  Kathleen G.  Berrill  John-Pascal 《New Forests》2022,53(1):1-16

New Forests - Afforestation of pasture sites results in a net reduction in atmospheric CO2. Coast redwood (Sequoia sempervirens) is well suited to carbon forestry due to its rapid growth and...  相似文献   

Microbial biomass and N mineralization in relation to N supply of sugar beet under reduced tillage     

Christa Hoffmann  Heidrun Platte  Thomas Lickfett  Heinz-Josef Koch 《植物养料与土壤学杂志》1997,160(2):187-193

Reduced tillage may affect N supply of plants by influencing soil microbial biomass and thereby N release. The aim of this study was to evaluate changes in microbial biomass due to tillage in relation to N mineralization and to assess the contribution to the N supply of sugar beet. For this purpose, in a field trial near Göttingen in 1995 microbial biomass and net N mineralization were determined in an in situ incubation of ploughed and reduced tilled soil in plots which were not given application of mineral N fertilizer. In reduced tilled soil the increase in mineral N concentration in the upper 10 cm of soil was mainly attributed to an increase in microbial biomass. The organic matter was more easily decomposable, indicated by the increase in C_mic/C_org and N_mic/N_t ratios; this was further supported by the enhanced turnover of microbial biomass in reduced tillage plots. A regression function was used to relate seasonal fluctuations of microbial biomass, soil moisture and soil temperature to N mineralization rate. There was a good agreement between measured and calculated N mineralization rate. Reduced tillage affected N mineralization by affecting the quantity and quality of microbial biomass. In 0–30 cm soil depth 169 kg N/ha were mineralized, 30 kg more N than in ploughed soil. However, despite improved N availability, the N uptake of sugar beet was decreased in reduced tilled soil. Because the N concentration in plants did not differ, it was concluded that sugar beet growth in reduced tilled soil was impaired due to other factors than N supply.  相似文献   

Ectomycorrhizal fungal diversity, tree diversity and root nutrient relations in a mixed Central European forest   总被引：1，自引：0，他引：1  

Lang C  Polle A 《Tree physiology》2011,31(5):531-538

Knowledge is limited about whether root nutrient concentrations are affected by mixtures of tree species and interspecific root competition. The goal of this field study was to investigate root nutrient element concentrations in relation to root and ectomycorrhizal (EM) diversity in six different mixtures of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia sp.) in an old-growth, undisturbed forest ecosystem. Root biomass and nutrient concentrations per tree taxon as well as the abundance and identity of all EM fungi were determined in soil cores of a volume of 1 L (r=40 mm, depth=200 mm). Stand-level nutrient concentrations in overall root biomass and H' (Shannon-Wiener diversity) were obtained by pooling the data per stand. At stand level, Shannon H' for roots and aboveground tree species abundance were correlated. H' for roots and EM fungi were not correlated because of the contribution of ash roots that form only arbuscular mycorrhizal but no EM associations. Nutrient element concentrations in roots showed taxon-related differences and increased in the following order: beech?≤?lime?相似文献   

Immunological detection of decay in wood     

J. Jellison  B. Goodell 《Wood Science and Technology》1988,22(4):293-297

Summary An enzyme-linked immunosorbent assay (ELISA) was used to detect and quantify Postia placenta (Fr.) M. Lars. et Lomb. in decaying wood. The fungus was detected as early as ten days after inoculation suggesting that ELISA may be effective in detecting early incipient decay. Decay-induced weight loss in P. placenta decayed spruce blocks was correlated with the absorbance values obtained in the ELISA reaction.  相似文献   

Pristiphora abietina (Hym., Tenthredinidae)— ein Bioindikator für Luftverschmutzung? Besonderheiten unreifer Fichtennadeln als Larvenfutter     

Christa Schafellner  R. Berger  E. Führer 《European Journal of Forest Research》1993,112(1):116-128

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Cell identity mediates the response of Arabidopsis roots to abiotic stress   总被引：1，自引：0，他引：1  

Dinneny JR  Long TA  Wang JY  Jung JW  Mace D  Pointer S  Barron C  Brady SM  Schiefelbein J  Benfey PN 《Science (New York, N.Y.)》2008,320(5878):942-945

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Biologische Bodeneigenschaften in Obstbau- und Baumschulbetrieben bei ökologischer und integrierter Bewirtschaftung und verschiedener organischer N-Düngung     

Heinz-Christian Fründ  Werner Dierend  Henning Schacht  Christa Schütt 《Erwerbs-Obstbau》2006,48(4):130-138

In organic farming only organic N-fertilizers are allowed. They have to be mineralized by soil biota before they become effective for the plant. There are a number of different organic N-fertilizers offered commercially in order to allow for a precise management of the N-supply to plants in organic farming. We tested the effects of the fertilizers “Vinasse” (product resulting from sugar-beet molasses), “Haarmehlpellets” (pellets of grounded pig bristles), “Rizinusschrot” (grist of Ricinus communis seeds), “Phytopearls” (from maize conversion), “Maltaflor” (malt germs and “Vinasse”), “Horndünger” (horn parings) and manure on soil respiration, soil animal feeding activity, earthworm abundance, microbial biomass and the C_mic/N_mic-ratio in tree nurseries and apple fruit production under organic vs. integrated management respectively. The investigations were part of a two year lasting project regarding yield effects and N-turnover that has already been reported in this journal (vol. 48/3: Dierend et al. 2006a, 2006b, Schacht et al. 2006). Significant differences between fertilized plots and unfertilized control plots were observed only at one of the four sites (Jork, organic fruit production) in soil respiration and in soil animal feeding activity. There were no significant differences in the soil biological parameters between plots that had received different types of organic fertilizers. There were also no significant differences between different levels of fertilizer application which were ranging from 30 to 135?kg N/ha. The soils from the four investigation sites differed significantly in their biological status. At the tree nurseries there were only few earthworms (ca. 15/m²) and a low microbial biomass (105 ... 190?mg C_mik/kg dry soil). The soils under fruit production were more intensively colonized by soil organisms, according to the lower degree of soil disturbance in these cultures. In tree nursery as well as in fruit production the soils under organic management had higher microbial biomasses and a wider ratio of C to N in the microbial biomass compared to their counterparts with integrated management. This is indicating that there is a stronger tendency to incorporate additional N into the microbial biomass in the organically managed soils. If there is a high activity of (endogeic) earthworms the nutrients are quickly remobilized and so become available for the plants.  相似文献