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1.
Lam TJ van Veersen JC Sampimon OC Olde Riekerink RG 《Tier?rztliche Praxis. Ausgabe G, Grosstiere/Nutztiere》2011,39(2):95-100
In this article an on-farm monitoring approach on udder health is presented. Monitoring of udder health consists of regular collection and analysis of data and of the regular evaluation of management practices. The ultimate goal is to manage critical control points in udder health management, such as hygiene, body condition, teat ends and treatments, in such a way that results (udder health parameters) are always optimal. Mastitis, however, is a multifactorial disease, and in real life it is not possible to fully prevent all mastitis problems. Therefore udder health data are also monitored with the goal to pick up deviations before they lead to (clinical) problems. By quantifying udder health data and management, a farm is approached as a business, with much attention for efficiency, thought over processes, clear agreements and goals, and including evaluation of processes and results. The whole approach starts with setting SMART (Specific, Measurable, Acceptable, Realistic, Time-bound) goals, followed by an action plan to realize these goals. 相似文献
2.
Complementary DNA sequencing: expressed sequence tags and human genome project 总被引：227，自引：0，他引：227
M D Adams J M Kelley J D Gocayne M Dubnick M H Polymeropoulos H Xiao C R Merril A Wu B Olde R F Moreno 《Science (New York, N.Y.)》1991,252(5013):1651-1656
Automated partial DNA sequencing was conducted on more than 600 randomly selected human brain complementary DNA (cDNA) clones to generate expressed sequence tags (ESTs). ESTs have applications in the discovery of new human genes, mapping of the human genome, and identification of coding regions in genomic sequences. Of the sequences generated, 337 represent new genes, including 48 with significant similarity to genes from other organisms, such as a yeast RNA polymerase II subunit; Drosophila kinesin, Notch, and Enhancer of split; and a murine tyrosine kinase receptor. Forty-six ESTs were mapped to chromosomes after amplification by the polymerase chain reaction. This fast approach to cDNA characterization will facilitate the tagging of most human genes in a few years at a fraction of the cost of complete genomic sequencing, provide new genetic markers, and serve as a resource in diverse biological research fields. 相似文献
3.
In this paper a review is given of frequently used mastitis diagnostic methods in modern dairy practice. Methods used at the quarter, cow, herd and regional or national level are discussed, including their usability for performance monitoring in udder health. Future developments, such as systems in which milk-derived parameters are combined with modern analytical techniques, are discussed. It is concluded that, although much knowledge is available and science is still developing and much knowledge is available, it is not always fully exploited in practice. 相似文献
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5.
Resource availability and limiting factors for bacterial growth during early stages of soil development (8-138 years) were studied along a chronosequence from the glacial forefield of the Damma glacier in the Swiss Alps. We determined bacterial growth (leucine incorporation) and we investigated which resource (C, N or P) limited bacterial growth in soils formed by the retreating glacier. The latter was determined by adding labile sources of C (glucose), N and P to soil samples and then measuring the bacterial growth response after a 40 h incubation period. Bacterial growth increased with increasing soil age in parallel with the build up of organic matter. However, lower bacterial growth, when standardized to the amount of organic C, was found with time since the glacier retreat, indicating decreasing availability of soil organic matter with soil age. Bacterial growth in older soils was limited by the lack of C. The bacteria were never found to be limited by only N, only P, or N + P. In the youngest soils, however, neither the addition of C, N nor P singly increased bacterial growth, while a combination of C and N did. Bacterial growth was relatively more limited by lack of N than P when the C limitation was alleviated, suggesting that N was the secondary limiting resource. The availability of N for bacterial growth increased with time, as seen by an increased bacterial growth response after adding only C in older soils. This study demonstrated that bacterial growth measurements can be used not only to indicate direct growth effects, but also as a rapid method to indicate changes in bacterial availability of nutrients during soil development. 相似文献
6.
Olde Riekerink RG Barkema HW Veenstra S Poole DE Dingwell RT Keefe GP 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(6):567-572
The purpose of this study was to 1) estimate the herd prevalence of contagious mastitis pathogens in bulk milk from Prince Edward Island (PEI) dairy farms, 2) determine the association between bulk milk culture results and mean bulk milk somatic cell count (BMSCC), and 3) investigate the agreement of repeated bulk milk cultures. Three consecutive bulk milk samples were obtained at weekly intervals from all 258 PEI dairy herds and were cultured using routine laboratory methods. Cumulative prevalence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. (M. bovis and M. alkalescens) was 74%, 1.6%, and 1.9%, respectively. Bulk milk somatic cell count of Staph. aureus-positive herds was higher than that of negative herds. Agreement for Staph. aureus isolation between 3 consecutive tests was moderate (kappa = 0.46). Mycoplasma bovis and M. alkalescens in bulk milk are being reported for the 1st time in PEI ever and in Canada since 1972. 相似文献
7.
Pieterse N. M. Verkroost A. W. M. Wassen M. Olde Venterink H. Kwakernaak C. 《Landscape Ecology》2002,17(1):69-81
Despite efforts that have been put into conservation, there is a continuing loss of species and ecosystems in Western Europe. There is a growing awareness that restoration is an essential step to stop this tide. Unfortunately, there is lack of understanding about the multitude of functions and the complexity of spatial interactions in a landscape. The focus of this paper is to demonstrate that an Integrated Decision Support System (IDSS) is indispensable to offer insight in this complexity and to design efficient restoration programmes. The IDSS is applied in a lowland catchment on the border between The Netherlands and Belgium and leads to the following recommendations: (1) The site conditions on the location where restoration is planned must be close to the range that is required for the target ecosystem. (2) The manager has to decide for the most attainable targetecosystem, and accept the inevitable loss of other ecosystems as a result from this choice. (3) Restoration planning involves that the optimal measure for each catchment, subcatchment or region is assessed, being ecological, urban or agricultural. (4) For each ecosystem an optimal set of measures must be selected. An analysis of the restoration efficiency (ecological gain divided by economic costs) is crucial for this selection. 相似文献
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In 2004, an experiment was carried out to evaluate the effect of biological control through feeding spores of Duddingtonia flagrans on parasitic gastroenteritis in lambs, kept under an evasive grazing system. In total 66 lambs were used. Forty naturally infected 3-month old ram lambs were weaned in mid June, and divided into four groups of 10 lambs. On 21 June, G1–G4 were moved to four separate virtually clean plots, they were moved after 4 and 8 weeks to similar plots, and housed after 12 weeks to be necropsied 16 days later. The other 26 lambs had been raised helminth-free, and were used as pairs of tracer lambs. All but one of these pairs, were grazed during the last 2 weeks on each plot. The remaining pair (TA) was grazed during the last 2 weeks on pasture (30 August to 13 September) on the plot that had been grazed by G3 between 19 July and 16 August, to study inhibited development in Haemonchus contortus. All lambs were fed 200 g of concentrates daily throughout the whole period, and those of G1 and G2 were also fed 500,000 spores of D. flagrans/kg bodyweight daily.
The faecal cultures demonstrated a high reduction in yield as a result of fungal application. However, no differences between groups were seen in weight gain, faecal egg counts, pasture larval counts, worm counts and tracer worm counts. H. contortus was the dominant species, and it is obvious that the moves at 4-week intervals prevented the development of severe haemonchosis. This is in particular demonstrated by the much higher worm counts in the two TA tracer lambs grazed. Nevertheless, increases to high faecal egg counts 3 weeks after the first and second moves, indicated acquisition of infection before these moves and at least subclinical haemonchosis. This was supported with the worm counts of lambs and tracer lambs. A higher proportion of inhibited early L4 than in other tracers and than in the permanent lambs were found in the pair of TA tracer lambs. This indicates that moves to new pastures in late summer and autumn delays the onset of inhibition. 相似文献
9.
Mehri Tavakol Richard GM Olde Riekerink Otlis C Sampimon Willem JB van Wamel Alex van Belkum Theo JGM Lam 《Acta veterinaria Scandinavica》2012,54(1):28
During routinely screening (50.000 milk samples on an annual basis) 14 MRSA ST398 strains were identified in the period of January 2008 to September 2008 in 14 different dairy herds located in the provinces Overijssel and Gelderland, The Netherlands. Molecular analysis was performed by Cfr9I PFGE, ST398-specific diagnostic PCR, spa typing, SCCmec typing and Panton-Valentine Leukocidin (PVL) gene PCR. The molecular analyses of 14 MRSA (one MRSA strain per herd) strains revealed that all strains belong to ST398 with 3 closely related spa types (t011, t108 and t889, all commonly found in pigs) and carry 2 different SCCmec types, IVa and V. All MRSA strains were resistant to two or more classes of antibiotics and also PVL negative. The majority of farms (n = 9, 64%) harboured combined livestock with both cows and pigs present. Our study contributes to the growing evidence that MRSA ST398 is transmitted among various animal species and can be considered as an etiological agent of mastitis in dairy cows. 相似文献
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N.M.?PieterseEmail author H. Olde?Venterink P.P.?Schot A.W.M.?Verkroost 《Landscape Ecology》2005,20(6):743-753
There is an ongoing debate as to whether nutrient contamination of groundwater under agricultural fields may cause nutrient-enrichment
and subsequent eutrophication in discharge areas. Often, there is only circumstantial evidence to support this supposition
(proximity of agricultural fields, direction of water flow, highly productive vegetation). Research on solute transport along
a flow path is necessary to evaluate the risk for eutrophication. In this paper we present results of such a study. Two transects
were established in a discharge meadow, a few meters downstream from fertilized cornfields. Highly productive vegetation in
parts of the meadow suggested nutrient-enrichment caused by inflow of contaminated groundwater. This supposition was supported
by an analysis of groundwater flow paths, residence times and chloride as tracer for pollution. However, the fate of nutrients
along the flow path indicated otherwise. While we found high concentrations of DIN (dissolved inorganic nitrogen), P and K
under the cornfields, DIN and P concentrations drop below detection limit when groundwater enters the meadow. Only K progressed
into the meadow but did not enter the root zone. We conclude that (1) polluted groundwater from the cornfields did not cause
the nutrient-enrichment, as indicated by the highly productive vegetation. Restoration projects in discharge areas should
not focus upon measures in upstream areas if only circumstantial evidence is available. Solute transport should be considered
as well. (2) Because K clearly showed to be the most mobile nutrient, its importance for nutrient-enrichment in discharge
wetlands merits more attention in future research. 相似文献