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Khol JL Franz S Klein D Lexer D Waiblinger S Luger K Baumgartner W 《Berliner und Münchener tier?rztliche Wochenschrift》2006,119(1-2):68-73
The teats of Brown Swiss and Austrian Simmental cows, divided into two groups, one milked by means of an automatic milking system, the other using a conventional milking parlour, were examined monthly by ultrasonography. Aim of the study was to compare the effects of two different milking machines upon the structures of the bovine teat canal and wall by ultrasonography and thereby evaluate ultrasonography as a research tool for visualisation of different influences on the bovine teat. Length and thickness of the teat canal and teat wall thickness were measured and analysed. During lactation, teat canal length and thickness increased in both groups, teat canal length decreased in conventional milked cows at the end of lactation. Shorter and narrower teat canals were observed in automatic milked cows. Differences between the groups in teat canal length and thickness were determined in early lactation. During lactation teat wall thickness showed a slight increase. Automatic milked cows displayed thinner teat walls than cows milked in the milking parlour. Teat morphology was influenced by the number and duration of lactations, milk yield, quarter of the udder and time and date of examination. It was concluded that the effect of the two different milking machines caused significant differences in bovine teat morphology and that ultrasonography proved to be an appropriate method for visualising influences of the milking technique on the bovine teat. 相似文献
336.
Madin JS Alroy J Aberhan M Fürsich FT Kiessling W Kosnik MA Wagner PJ 《Science (New York, N.Y.)》2006,312(5775):897-900
Ecological interactions, such as predation and bioturbation, are thought to be fundamental determinants of macroevolutionary trends. A data set containing global occurrences of Phanerozoic fossils of benthic marine invertebrates shows escalatory trends in the relative frequency of ecological groups, such as carnivores and noncarnivorous infaunal or mobile organisms. Associations between these trends are either statistically insignificant or interpretable as preservational effects. Thus, there is no evidence that escalation drives macroecological trends at global and million-year time scales. We also find that taxonomic richness and occurrence data are cross-correlated, which justifies the traditional use of one as a proxy of the other. 相似文献
337.
Background
Despite the important role of goats for meat and milk production in Ethiopia, little information is available on the epidemiology of caprine tuberculosis (TB). Caprine TB is important as milk is usually consumed raw particularly by Ethiopian pastoralists. The objectives of the present study were to estimate the prevalence of TB in goats at an abattoir, to evaluate associated risk factors and to characterize the causative mycobacteria.Methods
A cross-sectional study was conducted on 1990 randomly selected male goats that were slaughtered at Luna Export Abattoir of central Ethiopia. Postmortem examination, mycobacterial culturing and molecular typing techniques like genus typing, deletion typing and spoligotyping were used.Result
The overall prevalence of caprine TB-like lesions was 3.5%. The lesion prevalence increased significantly with increasing age. Mycobacteria were found by culture and seen as acid fast bacilli in 12% of the goats with TB-like lesions. Characterization of the eight isolates using multiplex polymerase chain reaction (PCR) indicated that five of them belonged to the genus Mycobacterium. Four of the latter were confirmed to be members of the M. tuberculosis complex. Further characterization of the three M. tuberculosis isolates by spoligotyping identified them as type SIT53 and two new spoligotypes.Conclusion
The isolation of M. tuberculosis from goats in this study indicates a potential risk of transmission of M. tuberculosis between humans and goats. 相似文献338.
The content of soil organic matter (SOM) can be considered as an important factor for evaluating soil fertility, crop yields, and environmental effects. Sensitive measurements for the assessment of quantitative changes in SOM shortly after the conversion of the management practice would be helpful to understand the SOM‐transformation cycle in more detail. Changes in SOM are reflected in modifications of total organic‐carbon (TOC) and total organic‐nitrogen (TON) contents. They are initially detectable in the readily decomposable fraction. We used hot water–extractable carbon (HWC) and nitrogen (HWN) as measurement of labile pools of SOM and aimed to quantify changes in contents of these C and N fractions in a sandy soil already few years after changing management strategy. In this context, we examined the impact of the conversion of a succession fallow (F) to organic (O) and intensive (I) agriculture on TOC, total N (TN), HWC, and HWN. The conversion of succession fallow to cultivated land resulted in a significant decrease of TOC, TN, and HWC at 0–10 cm soil depth. On average, TOC decreased approx. 0.70 g C kg–1 (approx. 9% of initial TOC), TN decreased approx. 0.13 g N kg–1 (approx. 17% of initial TN), and HWC decreased approx. 0.05 g C kg–1 (approx. 12% of initial HWC) within 3 years. Relatively rapid changes in TOC and TN contents indicated comparatively high proportions of decomposable C and N. These were reflected in comparable high HWC (ranging from 0.37 to 0.59 g C kg–1 at 0–30 cm soil depth) and HWN (ranging from 0.04 to 0.10 g N kg–1 at 0–30 cm) contents. These high contents as well as the high HWC : TOC and organic hot water–extractable N (HWNorg) : TN ratios (both between 5% and 7%) implied that the soil investigated has a high ability to provide short‐term available organic C and N compounds. Long‐lasting applications of high quantities of organic fertilizer in the past and high quantities of rhizodepositions were assumed as reasons for the high capability of soil to provide short‐term to medium‐term available C and N. Changes in the HWN content due to the fertilization or crop rotation were mainly based on changes in its inorganic part. This ranged between 10% and 30% of HWN. By discriminant function analysis, it could be shown that the HWN represents a suitably sensitive measurement for the determination of management‐specific impacts in terms of the N, but also of the C cycle. In combination with other C and particularly with other N parameters, the HWN allowed a statistically significant separation of comparable sites varying in management practice already 2 years after the conversion of the management system. 相似文献
339.
Thyme (Thymus vulgaris L., Lamiaceae) is a subshrub from the Lamiaceae family with plants that are rich in essential oils and antioxidative phenolic substances. Twelve accessions originating from southern France and the variety 'Deutscher Winter' were grown in an experimental field in eastern Austria. Leaf samples from these plants as well as from a commercial thyme rich in thymol were analyzed for their essential oil and the antioxidative potential in various extracts. The assays for antioxidative activity were the total phenolics according to the Folin-Ciocalteu method, DPPH decoloration, and Fe(3+) reduction (FRAP). Both extraction techniques used, in the water bath at 40 degrees C and in the ultrasonic bath at room temperature, proved to be efficient. The best results were obtained with 60% ethanol as extractant. In the comparison of the different accessions the less active and the most active of these extracts differed by factors of 2.1 and 2.6 in the total phenolics and FRAP assay, respectively, and by factors 1.5-2.0 in the DPPH assay. Rosmarinic acid accounted for 22-55% of the antioxidant activity in the ethanolic extracts. Essential oils with high proportions of the phenolic components thymol and/or carvacrol showed the highest antioxidant activity. Ethanolic extracts from the residues after distillation were considerably lower in antioxidant activity than the respective extracts from the dried leaves. Extracts with CH2Cl2 in the ultrasonic bath contained volatiles in proportions close to the essential oil but displayed very low antioxidant activity. 相似文献
340.
Ilya Yevdokimov Andreas Gattinger Franz Buegger Jean Charles Munch Michael Schloter 《Biology and Fertility of Soils》2008,44(8):1103-1106
The changes in size, activity and structure of soil microbial community caused by N fertilization were studied in a laboratory
incubation experiment. The rates of N fertiliser applied (KNO3) were 0 (control), 100 and 2,000 μg N g−1 soil. Despite no extra C sources added, a high percentage of N was immobilized. Whereas no significant increase of microbial
C was revealed during incubation period, microbial growth kinetics as determined by the substrate-induced growth-response
method demonstrated a significant decrease in the specific growth rate of microbial community in soil treated with 2,000 μg
N g−1 soil. Additionally, a shift in microbial community structure resulting in an increase in fungal biomarkers, mainly in the
treatment with 2,000 μg N g−1 soil was visible. 相似文献