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81.
N, P and K budgets for crop rotations on nine organic farms in the UK   总被引:2,自引:0,他引:2  
Abstract. Nitrogen (N), phosphorus (P) and potassium (K) budgets were calculated for nine organic farms in the UK. The farms were situated on sandy loams, silty clay loams and silty loams over chalk with stockless farming systems and cattle, pig and poultry enterprises with a significant proportion of arable cropping. A soil surface nutrient budget was calculated for the target rotation on each farm using information about field management and measurements of the soil, crops and manure. Losses of N through leaching and volatilization were calculated independently using the nitcat and manner models. Nutrient budgets for seven of the farm rotations showed an N surplus, six a P surplus and three a K surplus. The ratio of N inputs supplied in the form of biological fixation : manure : atmospheric deposition was approximately 2 : 2 : 1 for stocked systems and 2 : 0 : 1 for stockless systems. Phosphorus surpluses resulted from supplementary P fertilizer (rock phosphate) and additional feed for non-ruminant livestock. The stockless system without P fertilizer resulted in a large P deficit and stocked systems, which relied on recycling manure alone, a small P deficit. Only rotations with large returns of manure or imported feed showed a K surplus or a balanced K budget.  相似文献   
82.
Abstract. The leaching of spring-applied fertilizer nitrogen was measured by soil sampling on three soils widely used for spring cropping: a loamy sand, a sandy loam and a sandy silt loam. Soils were fallow during the experiment. Results were compared with simulations obtained with a computer leaching model. The model differentiated well between soil types, and predicted mineral nitrogen remaining in the top 30, 60 or 90 cm with reasonable precision. It tended to over-estimate the rate of nitrification of ammonium from ammonium nitrate fertilizers. The causes of occasional large discrepancies between sampling and measurement are discussed.  相似文献   
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OBJECTIVE: To characterize the process by which owners search for lost cats and identify factors associated with time to recovery. DESIGN: Cross-sectional study. SAMPLE POPULATION: Owners of 138 cats lost in Montgomery County, Ohio, between June 1 and September 30, 2005. PROCEDURES: A telephone survey was conducted. RESULTS: 73 of the 138 (53%) cats were recovered; median time to recovery was 5 days (range, 0.5 to 81 days). Most cats (48 [66%]) that were recovered returned home on their own or were found in the neighborhood (5 [7%]); most other cats were recovered through posting of neighborhood signs (8 [11%]) or calling or visiting an animal agency (5 [7%]). The highest success rate for any of the search methods that were used was only 12% (posting neighborhood signs). Only 26 of the 138 (19%) cats had some type of identification at the time they were lost (ie, identification tag, rabies tag, or microchip). Owners allowed 82 (59%) cats to spend at least some time outdoors. The percentage of sexually intact cats recovered by their owners (4/16 [25%]) was significantly lower than the percentage of neutered cats recovered (69/122 [57%]). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the percentage of lost cats recovered by their owners is low, possibly in part because of the lack of use of traditional identification methods and the general acceptance that cats may roam. Veterinarians can help educate owners about the importance of identification and the need to keep cats indoors.  相似文献   
86.
Kerstin  Hansson  DVM  Jens  Häggström  DVM  PhD  Clarence  Kvart  DVM  PhD  Peter  Lord  BVSc  FRCVS 《Veterinary radiology & ultrasound》2002,43(6):568-575
Two-dimensional (2-D) echocardiographic measurement of the left atrium (LA) has the potential to be more accurate than the standard M-mode method, because the LA body can be measured. We evaluated a 2-D method for measuring LA and aorta (AO) in a right parasternal short-axis view and compared it to the M-mode method. An index for LA size (LA/AO) was calculated in 166 cavalier King Charles spaniels, 56 normal and 110 dogs with mitral regurgitation (MR) of varying degrees secondary to chronic valvular disease. In normal dogs, the AO-2-D and LA/AO-2-D did not correlate to body weight (BW) or BW2; whereas, all M-mode values and the LA-2-D were significantly (p < .05) related to both BW parameters. In normal dogs, there was no difference between M-mode and 2-D indices. For all dogs (normal and dogs with MR) there was an 11% bias between the M-mode and 2-D index with the LA/AO-2-D being higher than the LA/AO-M. The association between the mean and the difference of the indices demonstrated a quadratic relationship. Dogs with a mean LA/AO of 2.0-2.5 showed the largest difference between the two indices. Small values for the 2-D coefficients of variation for respiration and stage of diastole were found; 3.4 and 3.1%, respectively. The 2-D index is more sensitive to LA enlargement than the M-mode index.  相似文献   
87.
OBJECTIVE: To characterize the process by which owners search for lost dogs and identify factors associated with time to recovery. DESIGN: Cross-sectional study. SAMPLE POPULATION: Owners of 187 dogs lost in Montgomery County, Ohio, between June 1 and September 30, 2005. PROCEDURES: A telephone survey was conducted. RESULTS: 132 of the 187 (71%) dogs were recovered; median time to recovery was 2 days (range, 0.5 to 21 days). Dogs were recovered primarily through a call or visit to an animal agency (46 [34.8%]), a dog license tag (24 [18.2%]), and posting of neighborhood signs (20 [15.2%]). Eighty-nine (48%) dogs had some type of identification at the time they were lost (ie, identification tag, dog license tag, rabies tag, or microchip). Owners had a higher likelihood of recovery when they called an animal agency (hazard ratio, 2.1), visited an animal agency (1.8), and posted neighborhood signs. Dogs that were wearing a dog license tag also had a higher likelihood of recovery (hazard ratio, 1.6). Owners were less likely to recover their dogs if they believed their dogs were stolen (hazard ratio, 0.3). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that various factors are associated with the likelihood that owners will recover a lost dog. Both animal agencies and veterinarians can play a role in educating dog owners on the importance of identification tags, licensing, and microchips and can help to emphasize the importance of having a search plan in case a dog is lost.  相似文献   
88.
Background: Pulmonary edema and venous congestion are well‐recognized signs of congestive heart failure (CHF) in advanced canine chronic mitral regurgitation (MR). However, little is known about pulmonary blood volume (PBV), blood pulmonary transit time (PTT), and the regulation of these. Objectives: To measure and evaluate the relationships of PBV, forward stroke volume (FSV), and heart rate normalized blood pulmonary transit time (nPTT) in healthy dogs and dogs with MR. Animals: Thirty‐three Cavalier King Charles Spaniels; 11 healthy, 4 in modified New York Heart Association (NYHA) class I, 11 in class II, and 7 in CHF. Methods: Heart rate normalized PTTs were measured by radionuclide angiocardiography. Left ventricular end diastolic and systolic diameter, left atrial/aortic root ratio, and FSV were measured by echocardiography. PBV and pulmonary blood volume index (PBVI) were calculated by established formulas. Results: PBVI was 308 ± 56 (mean ± SD) mL/m2 for healthy dogs, 287 ± 51 mL/m2 in NYHA class I, 360 ± 66 mL/m2 in Class II, and 623 ± 232 mL/m2 in CHF (P= .0008). Heart rate normalized PTT, not FSV, was a predictor of PBV (r= 0.92 and 0.02, respectively). Conclusions and Clinical Importance: Increased PBV, not decreased FSV, is the main cause of increased nPTT in MR. Increased nPTT can be used as an indicator of abnormal cardiopulmonary function in dogs with MR.  相似文献   
89.
Background: The contribution of right heart (RH) chamber enlargement to general heart enlargement seen on thoracic radiographs in mitral regurgitation (MR) is not known.
Objectives: To determine the size and shape of the RH chambers in normal dogs and dogs with varying degrees of MR.
Animals: Fifty-four privately owned dogs: 13 normal, 41 with varying degrees of MR including 25 with congestive heart failure (CHF).
Methods: Archived first pass radionuclide angiocardiograms were used to produce static images of the RH and left heart (LH) chambers. Indexes of size and shape of the RH and LH chambers were related to severity of MR determined by heart rate-normalized pulmonary transit time (nPTT), vertebral heart scale (VHS), and clinical status. RH shape was measured by a circularity index of RH short axis/long axis.
Results: A 2nd degree polynomial fit best described the ratios; RH/LH dimension to nPTT ( R 2= 0.62) and to VHS ( R 2= 0.43), RH/LH area to nPTT ( R 2= 0.64) and to VHS ( R 2= 0.58), all P < .001. RH circularity was decreased in CHF, P < .001. In CHF, the RH chambers of 16 dogs were both flattened and enlarged, whereas 9 had convex septal borders.
Conclusions: RH chambers are not significantly dilated in dogs with mild to moderate MR without CHF. In CHF, RH chambers enlarge and also may be compressed by the LH chambers. Pulmonary hypertension probably is present in some dogs with CHF. Increased sternal contact is not a useful sign of right-sided heart dilatation in MR.  相似文献   
90.
Personalized identification (ID) tags that contain contact information for the dog or cat owner can help assure lost animals are quickly reunited with their owners. The authors have previously reported that while the majority of pet owners stated that ID tags were very important, only a third responded that their pet wears an ID tag. The objective of this study was to evaluate if providing and putting on the pet a free collar and ID tag during an owner's visit to a veterinary hospital or spay/neuter facility increased the likelihood that the pet owners would actually keep the identification on their pet at least 6-8 weeks after they were placed on the pet. A second population of dogs and cats that were adopted from animal control and humane society shelters were also studied to assess retention of a collar and personalized ID tag. Telephone follow-up occurred a mean of 8 weeks after the tag was applied. Retaining and using the tag significantly increased for the veterinary group with 13.8% reporting their pets were currently wearing an ID tag pre-intervention, and 84.3% reporting their pets were currently wearing and ID tag post-intervention. Of the dogs and cats that were adopted, at follow-up 94% of owners reported their pets were currently wearing an ID tag. Approximately 5% of those who participated in the post-intervention survey lost a pet and recovered that pet because of the ID tag. This suggests that ID tagging is an effective method to potentially decrease stray intake into shelters and return pets home. The data also support placing tags and collars directly on pets as a method to retain those ID tags and collars on the animals, thus increasing the likelihood they will be returned home if lost or during a disaster.  相似文献   
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