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排序方式: 共有116条查询结果,搜索用时 15 毫秒
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P. Witt L. de Kroon N. Ankringa M. Delany L. W. L. van Bruggen R. van den Boom M. M. Sloet van Oldruitenborgh-Oosterbaan E. W. Siegers 《Equine Veterinary Education》2022,34(9):e369-e374
A 2-month-old Warmblood colt presented with recurrent colic and regurgitation. Gastroscopy, performed on several occasions, and barium-contrast radiography revealed severe squamous gastric ulceration and stenosis at the level of the margo plicatus. Treatment with omeprazole reduced the extent and severity of the gastric ulcers but did not affect the stenosis. The foal was euthanised because of a poor prognosis, and post-mortem examination confirmed the clinical diagnosis. Severe squamous gastric ulceration, granulation tissue formation and cicatrisation of deep gastric lesions were considered to have caused the stenosis. Gastroduodenal outflow obstruction is a recognised disorder in foals, but stenosis at the level of the margo plicatus has not been reported in foals or adult horses. To the authors' knowledge, this is the first case of severe squamous gastric ulceration, complicated by stenosis at the level of the margo plicatus, in a foal. Although rare, gastric stenosis should be considered in foals suffering recurrent colic and regurgitation. 相似文献
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Soil microbial biomass and nitrogen supply in an irrigated lowland rice soil as affected by crop rotation and residue management 总被引:5,自引:0,他引:5
C. Witt Kenneth G. Cassman Johannes C. G. Ottow Ulrich Biker 《Biology and Fertility of Soils》1998,28(1):71-80
Processes that govern the soil nitrogen (N) supply in irrigated lowland rice systems are poorly understood. The objectives
of this paper were to investigate the effects of crop rotation and management on soil N dynamics, microbial biomass C (CBIO) and microbial biomass N (NBIO) in relation to rice N uptake and yield. A maize-rice (M-R) rotation was compared with a rice-rice (R-R) double-cropping
system over a 2-year period with four cropping seasons. In the M-R system, maize (Zea mays L.) was grown in aerated soil during the dry season (DS) followed by rice (Oryza sativa L.) grown in flooded soil during the wet season (WS). In the R-R system, rice was grown in flooded soil in both the DS and
WS. Three fertilizer N rates (0, 50 or 100 kg urea-N ha–1 in WS) were assigned to subplots within the cropping system main plots. Early versus late crop residue incorporation following
DS maize or rice were established as additional treatments in sub-subplots in the second year. In the R-R system, the time
of residue incorporation had a large effect on NO3
–-N accumulation during the fallow period and also on extractable NH4
+-N, rice N uptake and yield in the subsequent cropping period. In contrast, time of residue incorporation had little influence
on extractable N in both the fallow and rice-cropping periods of the M-R system, and no detectable effects on rice N uptake
or yield. In both cropping systems, CBIO and NBIO were not sensitive to residue incorporation despite differences of 2- to 3-fold increase in the amount of incorporated residue
C and N, and were relatively insensitive to N fertilizer application. Extractable organic N was consistently greater after
mid-tillering in M-R compared to the R-R system across N rate and residue incorporation treatments, and much of this organic
N was α-amino N. We conclude that N mineralization-immobilization dynamics in lowland rice systems are sensitive to soil aeration
as influenced by residue management in the fallow period and crop rotation, and that these factors have agronomically significant
effects on rice N uptake and yield. Microbial biomass measurements, however, were a poor indicator of these dynamics.
Received: 31 October 1997 相似文献
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AEM Horta JP Barbas CC Marques MC Baptista MI Vasques RM Pereira RD Mascarenhas S Cavaco‐Gonçalves 《Reproduction in domestic animals》2010,45(6):e412-e416
The effect of vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination (AI) upon the site of AI (vaginal or cervical) and fertility was studied using a total of 87 estrous synchronized Serra da Estrela ewes (control n = 42 and treated n = 45). Artificial insemination was performed using refrigerated semen at 54–55 h after sponge removal. Lambing rate (fertility) and prolificacy were compared between control and treated ewes. The effect of the site of semen deposition on fertility was also evaluated. Prolificacy rate was not different between control (1.5) and treated (1.59) ewes. The proportion of cervical AI achieved in control (45.2%) and treated (37.8%) ewes was not significantly different. Overall, fertility was significantly lower in control than in treated ewes (42.9% vs 64.4%; p < 0.04). Fertility following vaginal AI was significantly lower for control for than treated ewes (30.4% vs 60.7%; p < 0.03) but the difference was smaller and not significant for cervical AI (control 57.9% vs 70.6%). It was concluded that vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination did not affect the proportion of cervical inseminations but significantly improved the fertility of treated ewes. Although needing confirmation, it was hypothesized that drugs might have induced local secretory modifications leading to an increase of cervical ability to retain more viable spermatozoa for fertilization. 相似文献
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BA Hampson JM Morton PC Mills MG Trotter DW Lamb CC Pollitt 《Australian veterinary journal》2010,88(5):176-181
Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8–16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled. 相似文献
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Panagiotis Mantis DVM Christopher R. Lamb MA VetMB Angela L. Witt DVM Reto Neiger Dr Med Vet PhD 《Veterinary radiology & ultrasound》2003,44(6):682-685
Trilostane, a 3beta-hydroxysteroid dehydrogenase inhibitor, has been used successfully over the last few years for the treatment of canine pituitary-dependent hyperadrenocorticism. In a prospective study of 19 dogs with pituitary-dependent hyperadrenocorticism, the adrenal glands were measured before and at least 6 months after initiation of trilostane therapy. Right adrenal gland length and caudal pole thickness and left adrenal gland caudal pole thickness increased significantly (p < or = 0.05); there was no significant change in left adrenal gland length. Enlargement of adrenal glands during trilostane therapy may occur as a result of suppression of the negative feedback mechanism affecting cortisol production. 相似文献