Milk fever and subclinical hypocalcaemia--an evaluation of parameters on incidence risk, diagnosis, risk factors and biological effects as input for a decision support system for disease control.     

H Houe  S ?stergaard  T Thilsing-Hansen  R J J?rgensen  T Larsen  J T S?rensen  J F Agger  J Y Blom 《Acta veterinaria Scandinavica》2001,42(1):1-29

The present review analyses the documentation on incidence, diagnosis, risk factors and effects of milk fever and subclinical hypocalcaemia. It is hereby evaluated whether the existing documentation seems sufficient for further modelling in a decision support system for selection of a control strategy. Several studies have been carried out revealing an incidence of milk fever most often in the level of 5-10%. Few studies indicate that the incidence of subclinical hypocalcaemia is several times higher than milk fever. The diagnosis based on clinical or laboratory methods or based on presence of risk factors is outlined. The clinical symptoms of milk fever are highly specific and the disease level may thus be determined from recording of treatments. Diagnosis of subclinical hypocalcaemia needs to include laboratory examinations or it may be determined by multiplying the incidence of milk fever by a certain factor. From the documentation on risk factors, it is very complex to predict the incidence from the exposure level of the risk factors. Due to uncertainty, sensitivity analyses over a wide range of values for each parameter are needed. The documentation of cow characteristics, nutrition, environment and management as risk factors are described. Among cow characteristics, parity or age, body condition and production level were found to be important. Risk factors associated with nutrition included most importantly dietary cation-anion difference and calcium level whereas the importance of general feeding related factors like type of feed stuff and feeding level were less clear. Environment and management included season, climate, housing, pasturing, exercise, length of dry period and prepartum milking. Several of the parameters on environment and management were confounded among each other and therefore firm conclusions on the importance were difficult. The documentation of the effect of milk fever includes the downer cows, reproductive disorders, occurrence of other diseases and the effect on milk production, body weight and culling. The reproductive disorders included most importantly dystocia, uterine prolapse, retained placenta, metritis and repeat breeding, and occurrence of other diseases included ketosis, displaced abomasum and mastitis. The documentation was substantial and often quantifiable within certain limits. Overall it is concluded that the present documentation on milk fever concerning incidence, diagnosis, risk factors and effects seems sufficient for a systematic inclusion in a decision support system. A model on milk fever should take into consideration the variation in biological data and individual herd characteristics. The inclusion of subclinical hypocalcaemia would be more uncertain and probably should await further documentation on possibilities of determining the herd level incidence and also the effect of this condition on production.  相似文献   

Epidemiology and diagnosis of Mycobacterium tuberculosis in captive Asian elephants (Elephas maximus).     

S K Mikota  L Peddie  J Peddie  R Isaza  F Dunker  G West  W Lindsay  R S Larsen  M D Salman  D Chatterjee  J Payeur  D Whipple  C Thoen  D S Davis  C Sedgwick  R J Montali  M Ziccardi  J Maslow 《Journal of zoo and wildlife medicine》2001,32(1):1-16

The deaths of two Asian elephants (Elephas maximus) in August 1996 led the United States Department of Agriculture to require the testing and treatment of elephants for tuberculosis. From August 1996 to September 1999. Mycobacterium tuberculosis infection was confirmed by culture in 12 of 118 elephants in six herds. Eight diagnoses were made antemortem on the basis of isolation of M. tuberculosis by culture of trunk wash samples; the remainder (including the initial two) were diagnosed postmortem. We present the case histories, epidemiologic characteristics, diagnostic test results, and therapeutic plans from these six herds. The intradermal tuberculin test, enzyme-linked immunosorbent assay serology, the blood tuberculosis test, and nucleic acid amplification and culture are compared as methods to diagnose M. tuberculosis infection in elephants.  相似文献   

Abdominal situs inversus in a sheep     

Larsen C  Kirk EJ 《New Zealand veterinary journal》1987,35(7):113-114

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Food intake adjustments of chicks: Short term reactions of genetic stocks to deficiencies in lysine,methionine or tryptophan     

D. O. Noble  M. L. Picard  E. A. Dunnington  G. Uzu  A. S. Larsen  P. B. Siegel 《British poultry science》1993,34(4):725-735

1. Growth, food intake, and food preference were measured in two experimental lines (White Rocks and White Leghorns) of chickens fed diets varying in content of lysine, methionine, or tryptophan. Diet A was balanced in all amino acids, while the remaining 6 diets were moderately ( ～ 30%) or slightly ( ～ 15%) deficient in either lysine, methionine, or tryptophan relative to NRC recommendations for broiler diets.

2. Body weight and food utilisation efficiency of White Leghorns at 10 d of age were not affected by diet, whereas the lower concentrations of lysine and methionine depressed these traits in White Rocks.

3. Tryptophan deficiency reduced food intake of White Leghorns, but not White Rocks.

4. With choice feeding of balanced and deficient diets from day 10 to 16, preferences between the diets were minimal for White Leghorns, whereas for White Rocks there was an almost immediate preference for the balanced diet, followed by lack of preference or preference for the deficient diet.

5. Apparently for some genetic stocks there is rapid adjustment to deficiencies in these amino acids with overconsumption, followed by compensation for preference of the balanced diet. The response, however, will vary depending on the deficient amino acid.  相似文献   

The qualitative assessment of glycosaminoglycans in the canine intervertebral disc using a critical electrolyte concentration staining technique.     

K G Braund  P Ghosh  T K Taylor  L H Larsen 《Research in veterinary science》1976,21(3):314-317

Through the use of a critical electrolyte concentration staining technique, the glycosaminoglycans (GAGs) in the nucleus pulposus region of the canine intervertebral disc were arbitrarily identified as "hyaluronic acid", chondroitin sulphate and keratan sulphate. Approximate estimates of GAG concentration could be qualitatively deduced by determining the appropriate GAG "ALCIANOPHILIC INDEX". This index was considered to be an effective qualitative adjunct to chemical quantitation of GAGs in the intervertebral disc.  相似文献   

Predicting the spatial distribution of ground flora on large domains using a hierarchical Bayesian model     

Hooten  Mevin B.  Larsen  David R.  Wikle  Christopher K. 《Landscape Ecology》2003,18(5):487-502

Accomodation of important sources of uncertainty in ecological models is essential to realistically predicting ecological processes. The purpose of this project is to develop a robust methodology for modeling natural processes on a landscape while accounting for the variability in a process by utilizing environmental and spatial random effects. A hierarchical Bayesian framework has allowed the simultaneous integration of these effects. This framework naturally assumes variables to be random and the posterior distribution of the model provides probabilistic information about the process. Two species in the genus Desmodium were used as examples to illustrate the utility of the model in Southeast Missouri, USA. In addition, two validation techniques were applied to evaluate the qualitative and quantitative characteristics of the predictions.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

Möglichkeiten zur Förderung und zum Einsatz von Nützlingen an Stadtbäumen     

Barbara Jäckel  Hartmut Balder  Kristina Hasselmann 《Gesunde Pflanzen》2002,54(7):218-226

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Spread of potato virus Y in potato cultivars (Solanum tuberosum L.) with different levels of sensitivity     

Nata&#x;a Mehle  Maja Kova   Nata&#x;a Petrovi   Maru&#x;a Pompe Novak  &#x;pela Baebler  Hana Kre i Stres  Kristina Gruden  Maja Ravnikar 《Physiological and Molecular Plant Pathology》2004,64(6):19

The aim of this work was to correlate the appearance of the symptoms, multiplication and spread of virus after mechanical inoculation of potato (Solanum tuberosum L.) cultivars showing different levels of susceptibility and sensitivity to Potato virus Y^NTN (PVY^NTN). The potato cultivars used were the resistant cultivar Sante and susceptible cultivars Igor, Pentland squire and Désirée. The spread of the virus PVY^NTN in infected plants was monitored using different methods: DAS-ELISA, tissue printing, immuno-serological electron microscopy and real-time PCR. In all three susceptible cultivars, the virus was detected in the inoculated leaves 4–5 days after inoculation. From there virus spread rapidly, first into the stem, then more or less simultaneously to the upper leaves and roots. Real-time PCR was shown to be very sensitive and enabled viral RNA to be detected in non-inoculated leaves of susceptible cultivar Igor earlier than other methods. Therefore, for exact studies of plant–virus interaction, a combination of methods which detect viruses on the basis of their different properties (coat protein, morphology or RNA) should be used to monitor the spread of viruses.  相似文献   

Rangeland Ecology and Management,Volume 71, Issue 4: Soil Health as a Transformational Change Agent for US Grazing Lands Management     

Justin Derner  Alexander Smart  Theodore Toombs  Dana Larsen  Rebecca McCulley  Jeff Goodwin  Scott Sims  Leslie Roche 《Herpetological Monographs》2018,40(4):127-128

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Effect of plant proteins and crystalline amino acid supplementation on postprandial plasma amino acid profiles and metabolic response in rainbow trout (Oncorhynchus mykiss)     

Marine Rolland  Bodil K. Larsen  Jørgen Holm  Johanne Dalsgaard  Peter V. Skov 《Aquaculture International》2015,23(4):1071-1087

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