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RL Sanson 《New Zealand veterinary journal》2013,61(4):223-233
AIM: To quantify the numbers and extent of movements off sheep and cattle farms in New Zealand, in order to construct more realistic simulation models to investigate how infectious diseases such as foot-and-mouth disease (FMD) might spread. METHODS: Farmers from 500 randomly selected farms, comprising 100 from each of the following sectors, viz beef, dairy, grazing/dairy heifer rearing, sheep, and mixed sheep and beef, were asked to fill in diaries in which they recorded the movements of all animals, products, people, vehicles and equipment coming on to or leaving their farms during two separate 3-week periods, representing relatively ‘busy’ and ‘quiet’ times of the year with respect to livestock movements. Where possible, the destination of each movement was identified and geo-coded, to allow the distance travelled to be calculated. Each movement was then classified according to the risk of transfer of FMD virus (FMDV), should the disease have been present on the study farm at the time of the movement. The data were then analysed to establish movement frequencies and distributions of distances travelled, by the different pastoral livestock sectors. RESULTS: Two hundred and seventeen farmers returned one or more diaries. One hundred and ninety-three farmers completed a Busy-period diary, recording a total of 12,052 movements off their farms, a crude average of 62.4 per 3-week period, or 2.97 per day. Of these, 4.0% involved the transport of livestock, equating to 0.12 livestock consignments per day. In contrast, 186 Quiet-period diaries were returned, recording a total of 10,885 movements off, representing a crude average of 58.5 during the 3-week period, or 2.78 per day. Of these, 2.1% involved livestock, equating to 0.06 livestock consignments per day. The mean and median distances travelled during the Busy periods were 30.9 km and 13.1 km, respectively (range 0–1,167 km). In comparison, the mean and median distances travelled during Quiet periods were 41.3 and 14 km, respectively (range 0.4–1,203 km). CONCLUSIONS: People, vehicles, livestock and other items can travel off pastoral livestock farms in New Zealand to other farms either directly or via saleyards over extensive distances. This has implications for the potential spread of infectious diseases such as FMD. Movement parameters intended for use in the InterSpread Plus inter-farm simulation model of FMD were established, which will facilitate the prediction of likely spread and efficacy of controls in the unlikely event of a real-life outbreak. 相似文献
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M Mutinati M Piccinno M Roncetti D Campanile A Rizzo RL Sciorsci 《Reproduction in domestic animals》2013,48(3):353-357
During physiological pregnancy, all tissues and, mostly, placenta and foetus require high amounts of oxygen. Reactive oxygen species (ROS), generated both by mother and foetus, are implicated in foetal growth because they promote replication, differentiation and maturation of cells and organs. Nevertheless, ROS excess, if not properly counterbalanced, may lead to an alteration in cell constituents, with harmful effects both on mother and foetus.ROS exert a biphasic effect because adequate ROS concentration is essential for embryo development, implant, foetal defence against uterine infections, steroidogenesis, pregnancy maintainance and partum. On the other hand, an uncontrolled ROS generation, beyond physiological antioxidant defences, may lead to embryo resorption, placental degeneration with subsequent alteration in maternal‐foetal exchanges, delay in foetal growth, pregnancy interruption, stillbirths. This review investigates the mechanisms underlying ROS generation and effects, throughout physiological and pathological pregnancy in sheep, with a look to antioxidants and their importance in such a critical phase of the reproductive cycle of the sheep. 相似文献
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Relationship of Shelled Corn Fungal Susceptibility to Carbon Dioxide Evolution and Kernel Attributes
Fifty‐one samples of shelled corn were rewetted to 21% wb moisture content (MC) and evaluated for susceptibility to fungal invasion using ergosterol measurements and a test kit that measures carbon dioxide (CO2) evolution. The sample attributes measured were percent germination, electrolyte leakage after soaking in deionized water, percent fines, and percent kernel infection. The difference in ergosterol content before and after incubation at 24°C was used as the standard measure of fungal growth. Differences in CO2 evolution among the samples were consistent with expectations for fungal growth based on storage history. The coefficients of determination (r2) for the linear regression of ergosterol difference with CO2 kit readings were 0.46–0.60. All were statistically significant (α = 0.001) and r2 values were slightly greater when four high‐oil corn samples were removed. These results indicate that the CO2 test can be used to assess fungal susceptibility of rewetted shelled corn, which may also be indicative of its susceptibility before rewetting. The linear regressions of kernel attributes with ergosterol difference (48 < n < 51) that were statistically significant included percent germination, r2 = 0.49 (α = 0.001); electrolyte leakage, r2 = 0.27 (α = 0.001); and percent fines determined with a 4.76‐mm sieve, r2 = 0.12 (α = 0.05). 相似文献
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Corn from three growing seasons was harvested, dried, and stored in small bins. Samples taken at harvest and after various periods of bin storage (up to 77 months) were evaluated by two primary tests: carbon dioxide evolution during accelerated storage at ≈20.5% moisture content and 26°C and electrolyte leakage from bulk (100 g) samples soaking in deionized water. The initial (t < 72 hr) slope of carbon dioxide evolution rate curves (SLOPE72) was used as a base measure of storability (i.e., potential for safe storage without significant mold invasion). In electrolyte leakage tests, both test temperature and initial sample moisture content influenced results. Additionally, water conductivity after 10 min was correlated (r = 0.79) with SLOPE72, implying that electrolyte leakage has the potential to provide rapid information regarding future storability. 相似文献
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PO Wennberg TF Hanisco L Jaegle DJ Jacob EJ Hintsa EJ Lanzendorf JG Anderson R Gao ER Keim SG Donnelly LAD Negro DW Fahey SA McKeen RJ Salawitch CR Webster RD May RL Herman MH Proffitt JJ Margitan EL Atlas SM Schauffler F Flocke CT McElroy TP Bui 《Science (New York, N.Y.)》1998,279(5347):49-53
The concentrations of the hydrogen radicals OH and HO2 in the middle and upper troposphere were measured simultaneously with those of NO, O3, CO, H2O, CH4, non-methane hydrocarbons, and with the ultraviolet and visible radiation field. The data allow a direct examination of the processes that produce O3 in this region of the atmosphere. Comparison of the measured concentrations of OH and HO2 with calculations based on their production from water vapor, ozone, and methane demonstrate that these sources are insufficient to explain the observed radical concentrations in the upper troposphere. The photolysis of carbonyl and peroxide compounds transported to this region from the lower troposphere may provide the source of HOx required to sustain the measured abundances of these radical species. The mechanism by which NO affects the production of O3 is also illustrated by the measurements. In the upper tropospheric air masses sampled, the production rate for ozone (determined from the measured concentrations of HO2 and NO) is calculated to be about 1 part per billion by volume each day. This production rate is faster than previously thought and implies that anthropogenic activities that add NO to the upper troposphere, such as biomass burning and aviation, will lead to production of more O3 than expected. 相似文献
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An unusual outbreak of contagious ovine ecthyma 总被引：1，自引：0，他引：1
CD HAWKINS TM ELLIS MK DAVIES RL PEET J. PARKINSON 《Australian veterinary journal》1991,68(6):210-211
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HC LIN SS WALLACE JW TYLER† RL ROBBINS JC THURMON‡ DF WOLFE 《Australian veterinary journal》1994,71(8):239-242
Summary The anaesthetic effects of intravenous tiletamine-zolazepam 6.6 mg/kg-ketamine 6.6 mg/kg (TK) and tiletamine-zolazepam 6.6 mg/kg-ketamine 6.6 mg/kg-xylazine 0.11 mg/kg (TKX) were evaluated in six wethers. Heart rate, respiration rate, arterial blood pressure, and the electrocardiogram were monitored during anaesthesia. Analgesia was tested by electrical stimulation in the left flank. Atropine (0.03 mg/kg) was given intramuscularly before induction, but after recording of baseline heart rate and respiratory rate. The duration of analgesia was 28.7 ± 6.9 min with TK and 82.8 ± 26.6 min with TKX. Heart rate increased significantly within 5 min after TK or TKX administration. Respiratory rate remained unchanged after TK administration, but increased significantly from 5 to 45 min after TKX administration. Arterial blood pressure decreased significantly at 15 min with TK and 30 min with TKX. Sheep remained recumbent for 201 min with TK and 166 min with TKX. All recovered uneventfully. We conclude that either TK or TKX may be used for anaesthetising sheep. 相似文献
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