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31.
Assessing hygiene proficiency on organic and conventional pig farms regarding pork safety: A pilot study in Finland 总被引:1,自引:0,他引:1
K.-M. Siekkinen L. Nuotio J. Ranta R. Laukkanen S. Hellstrm H. Korkeala R. Maijala 《Livestock Science》2006,104(1-2):193-202
A key element in the EU Common Agricultural Policy (CAP) will be a single farm payment system that is linked to compliance with rules on, for instance hygiene standards. However, there are no recommended methods for assessing the hygiene proficiency of pig production farms. The present study was undertaken to develop a method for this purpose. A first implementation was done on pilot scale; with a set of both conventional and organic pig farms (N = 15). Fifty hygiene-related factors were selected, especially with reference to the possible proliferation of enteric pathogens Listeria monocytogenes, Yersinia enterocolitica and Yersinia pseudotuberculosis. The factors were allocated into 8 evaluation categories: (1) general production management, (2) animal density, (3) the outdoor area for pigs, (4) pest and pet animals, (5) general hygiene in the piggery, (6) pen hygiene, (7) feed production hygiene, and (8) feeding hygiene. A farm questionnaire and a supplementary on-site observation form were devised, and one arbitrary scale of hygiene points assigned for each factor. In addition to the mailed questionnaires, one person subsequently visited all the farms, perused the questionnaire with the owners and completed the observation form. The hygiene scores of the farms in each evaluation category were compared both without weighting and with weighting based on expert opinions. The method proved to be feasible and applicable to different types of production. 相似文献
32.
Frauke Ecke Pernilla Christensen Per Sandström Birger Hörnfeldt 《Landscape Ecology》2006,21(4):485-497
Several studies indicate a long-term decline in numbers of different species of voles in northern Fennoscandia. In boreal Sweden, the long-term decline is most pronounced in the grey-sided vole (Clethrionomys rufocanus). Altered forest landscape structure has been suggested as a possible cause of the decline. However, habitat responses of grey-sided voles at the landscape scale have never been studied. We analyzed such responses of this species in lowland forests in Västerbotten, northern Sweden. Cumulated spring densities representing 22 local time series from 1980–1999 were obtained by a landscape sampling design and were related to the surrounding landscape structure of 2.5×2.5 km plots centred on each of the 22 1-ha trapping plots. In accordance with general knowledge on local habitat preferences of grey-sided voles, our study supported the importance of habitat variables such as boulder fields and old-growth pine forest at the landscape scale. Densities were negatively related to clear cuts. Habitat associations were primarily those of landscape structure related to habitat fragmentation, distance between habitat patches and patch interspersion rather than habitat patch type quantity. Local densities of the grey-sided vole were positively and exponentially correlated with spatial contiguity (measured with the fragmentation index) of old-growth pine forest, indicating critical forest fragmentation thresholds. Our results indicate that altered land use might be involved in the long-term decline of the grey-sided vole in managed forest areas of Fennoscandia. We propose two further approaches to reveal and test responses of this species to changes in landscape structure. 相似文献
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35.
In this study we examined the endocrine mediation between environmental factors (temperature and photoperiod) and the brain–pituitary–gonadal
axis in females of pejerrey Odontesthes bonariensis. Changes in the expression of brain gonadotropin-releasing hormones (GnRHs) and gonadotropin (GtH) subunit [follicle stimulating-β
(FSH-β), luteinizing hormone-β (LH-β), glycoprotein hormone-α (GPH-α)] genes, plasma gonadal steroids [estradiol (E2) and testosterone (T)], gonadal histology, and gonadosomatic index (GSI) in adult females exposed to combinations of short-day
(8 h) or long-day (16 h) photoperiods and low (12°C) or high (20°C) temperatures after winter conditions (8 h light, 12°C)
were analyzed. Pejerrey females kept under the short photoperiod had low GSIs, and their ovaries contained only previtellogenic
oocytes regardless of the experimental temperature. In contrast, females exposed to the long photoperiod had high GSIs and
ovaries with vitellogenic oocytes at both temperatures. These fish also showed a significantly higher expression of sGnRH,
pjGnRH, cGnRH-II (the three different GnRH variants found to date in the pejerrey brain), FSH-β, LH-β and GPH-α genes and
plasma E2 levels than those at the shorter photoperiod. No significant changes were observed in plasma T levels. Based on these results,
we concluded that the increase in day length but not that of temperature triggers the maturation of pejerrey females after
the winter period of gonadal rest and that this occurs by an integrated stimulation of the various components of the brain–pituitary–gonad
axis. 相似文献
36.
Do?Thi?XuanEmail author Vo?Thi?Guong Anna?Rosling Sadhna?Alstr?m Benli?Chai Nils?H?gberg 《Biology and Fertility of Soils》2012,48(2):217-225
Intensive cropping, especially of rice, is considered to contribute to negative effects not only on soil chemical and biological
properties but also on long-term grain yield. Appropriate crop rotation is often practiced as an alternative strategy to overcome
the negative side effects of intensive cropping. Although soil microbial diversity and community structure have been shown
to respond differently to altered agricultural management practices, little is known about possible links between crop rotation
and grain yield on bacterial communities in rice paddy soil. In this study, we investigated the impact of specific rotational
crops and compared it with intensive rice cultivation. The main crop rice (Oryza sativa) was rotated with maize (Zea mays) and mungbean (Phaseolus aureus) in different combinations in a system cultivating three crops per year. Soil bacterial communities were studied in two different
cropping periods using pyrosequencing of the variable V4 region of the 16S rRNA. Our results showed that rotation with alternative
crops increased rice yield by 24–46% depending on rotation structure and that bacterial community structure was altered in
the presence of mungbean and/or maize compared to that in rice monoculture. In the crop rotation systems, composition, abundance,
and diversity of soil bacterial communities were significantly different and higher than those in rice monoculture. Our results
show that effects of crop rotation relate to changes in soil bacterial community structure suggesting that appropriate crop
rotations provide a feasible practice to maintain the equilibrium in soil microbial environment for sustainable rice cultivation. 相似文献
37.
The viability of metapopulations in fragmented landscapes has become a central theme in conservation biology. Landscape fragmentation
is increasingly recognized as a dynamical process: in many situations, the quality of local habitats must be expected to undergo
continual changes. Here we assess the implications of such recurrent local disturbances for the equilibrium density of metapopulations.
Using a spatially explicit lattice model in which the considered metapopulation as well as the underlying landscape pattern
change dynamically, we show that equilibrium metapopulation density is maximized at intermediate frequencies of local landscape
disturbance. On both sides around this maximum, the metapopulation may go extinct. We show how the position and shape of the
intermediate viability maximum is responding to changes in the landscape’s overall habitat quality and the population’s propensity
for local extinction. We interpret our findings in terms of a dual effect of intensified landscape disturbances, which on
the one hand exterminate local populations and on the other hand enhance a metapopulation’s capacity for spreading between
habitat clusters. 相似文献
38.
39.
Sara Ringmark Arne Lindholm Ulf Hedenstr?m Michael Lindinger Kristina Dahlborn Clarence Kvart Anna Jansson 《Acta veterinaria Scandinavica》2015,57(1)
Background
Training of Standardbred race horses aims to improve cardiovascular and metabolic functions but studies on the effects of different training strategies from breaking till racing are lacking. Sixteen horses with the goal to race as 3-year-olds were studied from breaking (1-year-olds) to December as 3-year-olds. Horses were allocated to either a control (C) or reduced (R) training program from 2 years of age. The aim was to evaluate the effect of reducing the distance of high intensity exercise by 30% with respect to velocity at lactate concentration 4 mmol/l (VLa4), blood lactate and cardiovascular response. All training sessions were documented and heart rate (HR) was recorded. A standardized exercise test of 1,600 m was performed 10 times and a VLa4 test was performed five times.Results
C horses initially exercised for a longer time with a HR >180 beats per minute compared to R horses (P < 0.05) but after 6–9 months, time with HR >180 bpm decreased in C and were similar in the two groups (P > 0.05). Over the 2-year period, recovery HR after the 1,600 m-test decreased in both groups but was within 2 months lower in C than in R (P < 0.05). C horses also had lower resting HR as 3-year-olds (P < 0.01) than R horses. In C, post exercise hematocrit was higher than in R (P < 0.05). There was a tendency (P < 0.1) towards a larger aortic diameter in C as 3-year-olds (C: 1.75 ± 0.05, R: 1.70 ± 0.05 cm/100 kg BW). Left ventricle diameter and blood volume (in December as 2-year-olds) did not differ between groups. There were no differences between groups in post exercise blood lactate concentration or in VLa4. Both groups were equally successful in reaching the goal of participation in races.Conclusions
Horses subjected to a reduced distance of high intensity training from the age of 2 showed an attenuated heart rate response, but were able to maintain the same VLa4 and race participation as horses subjected to longer training distances. 相似文献40.
Morphological comparison of wild,farmed and hybrid specimens of two South American silversides,Odontesthes bonariensis and Odontesthes hatcheri 下载免费PDF全文
Sonia Alejandra Crichigno Ricardo Shohei Hattori Carlos Augusto Strüssmann Víctor Cussac 《Aquaculture Research》2016,47(6):1797-1808
In this study, body shape of hybrid and presumptive introgressed South American silversides was studied. Body shape of O. bonariensis and O. hatcheri from wild populations and farmed stocks was compared to provide basic information on the effects of fish farming on morphometric parameters. Subsequently, wild presumptive introgressed individuals and artificially hybridized farmed individuals were morphologically analysed to assess the effects of hybridization on the same parameters. Most farmed purebred individuals were shorter and higher than their wild counterparts, which is probably due to the favourable growth conditions compared to the wild habitat. However, the results evidenced that purebred individuals were more slender than both hybrid (farmed) fish and introgressed (wild) fish. Further studies on the growth performance of hybrid Odontesthes will be required in order to assess whether the combination of hybridization and sterilization could produce, under farming conditions, growth performances which satisfy the requirements of aquaculture. 相似文献