On the possible role of birds as transport hosts of 3rd-stage trichostrongyle larvae. Preliminary results     

Jrn Grnvold 《Acta veterinaria Scandinavica》1984,25(1):143-144

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A syndrome of hereditary tyrosinemia in mink (Mustela vison Schreb.).          下载免费PDF全文

K Christensen  P Fischer  K E Knudsen  S Larsen  H Srensen    O Venge 《Canadian journal of veterinary research》1979,43(3):333-340

A hereditary disease in mink (Mustela vison Schreb.) leading to death when the affected kits are about six weeks old has been investigated. The disorder is inherited as a simple autosomal recessive character. Strongly elevated plasma tyrosine concentration is an outstanding feature of the disease. An enzyme defect in tyrosine aminotransferase (EC 2.6.1.5) or 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27) is considered together with the possibility of a parallel between the disease in mink and the disease tyrosinosis or hereditary tyrosinemia in man.  相似文献   

Babesia motasi in sheep on the island of Gotland in Sweden     

Dan Christensson  Erik Thunegard 《Veterinary parasitology》1981,9(2):99-106

Serological survey with an IFA-test showed that 58% (73/125) of the lambs and 88% (46/52) of the ewes on the island of Gotland (Sweden) has antibodies against Babesia motasi.It is likely that such a high incidence of the blood protozoan organisms plays an important part in causing the often observed anaemia in sheep on that island.  相似文献   

The mammalian alimentary system. A functional approach: David S. Madge. Edward Arnold (Publishers) Ltd., London, 1975, 193 pp., £ 4.50 net     

Kirsten Christensen 《Livestock Production Science》1976,3(2):196

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Ostertagiasis in calves. I. The effect of control measures on infection levels and body weight gains during the grazing season in Denmark     

SV AA Henriksen  R.J. Jørgensen  P. Nansen  KR Sejrsen  J. Brolund Larsen  S. Klausen 《Veterinary parasitology》1976,2(3):259-272

The investigation was designed to study the gastro-intestinal helminth infection established in yearling calves with reference to fluctuations in the larval contamination of the herbage during the grazing season. In a 2 × 3 factor experiment, comprising six groups, each of six calves, a comparison was made between infection levels, growth rates etc. in calves grazing the same paddock over an entire season and calves moved before the July rise in herbage contamination to paddocks not grazed earlier in the same season. A comparison was also made between animals receiving no anthelminthic treatment, animals treated 3 weeks after the start of the grazing season and again when moved, and animals treated every 3 weeks during the season.Before July there were no weight gain differences between the various groups of calves. During the rest of the season, the calves which were moved gained 647–869 g, while those that remained on the same paddock, and were exposed to a high level of larval contamination gained only 81–361 g per day. The effect of anthelmintic treatment was less pronounced, though significant. The weight gains were correlated to a high degree with the larval contamination levels of the respective paddocks (r = ? 0.79) as well as with the serum pepsinogen (r = ? 0.75) and albumin levels (r = 0.75) of the calves and to a minor degree also with faecal egg counts (r = ? 0.45). The observed weight gain differences could not be accounted for by differences in grass quantity or quality.  相似文献   

Evaluation of the background for determination of vitamin requirements in pigs     

Kirsten Christensen 《Livestock Production Science》1980,7(6):569-590

The effects of vitamins on important production and performance traits have been evaluated from the present knowledge of the functions of vitamins in the organism and the effects of deficient and excess supplies.It is concluded that there is a lack of current knowledge on almost all aspects of quantitative metabolism of vitamins. Stress is laid on our need to understand problems of availability and sensitive parameters indicating the vitamin status of the organism.A clear distinction between the scientific determination of requirements, and the allowances recommended by advisers is emphasized. A safety margin has to be added to estimates of requirements to cover farm conditions.  相似文献   

Some factors influencing the exposure of grazing cattle to trichostrongyle infection     

P. Nansen  R. J. Jørgensen  J. W. Hansen  Kr. Sejrsen 《Veterinary research communications》1978,2(1):193-205

Fluctuations in the contamination of herbage with trichostrongylid nematode larvae are determined by a number of factors, the most important being climate and management. Practical measures to prevent calves from ingesting large numbers of larvae are based on detailed knowledge of the herbage contamination pattern and its epidemiological consequences. Intensification of animal husbandry methods including increased stocking rates and application of slurry to pasture may increase the hazards of gastrointestinal helminthiasis.

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Kurzfassung Die Fluktuation in der Weidekontamination durch Trichostrongylid-Nematodenlarven wird durch zahlreiche Faktoren bestimmt, deren wichtigste Klima und Bewirtschaftung sind. Praktische Kontrollmassnahmen zur Verhinderung einer hohen Larvenaufnahme durch die Kälber beruhen auf genauen Kentnissen der Weidelandkontaminationsschemata und ihrer epidemiologischen Folgen. Durch Intensivierung der Tierhaltungsmethoden, einschliesslich grösserer Stückzahlen und Düngen des Weidelands mit Jauche können die Gefahren einer gastrointestinalen Helminthiasis zunehmen.

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Resume La contamination des herbages par les larves de nématodes du genre des trichostrongyloides varie en fonction d'un nombre de facteurs, dont les plus importants sont les conditions climatiques et le mode d'exploitation. Les mesures pratiques de lutte visant à empêcher les veaux d'absorber une trop grande quantité de larves sont basées sur une étude détaillée des modalités de la contamination des herbages et de ses conséquences épidémiologiques. Le recours à des méthodes d'élevage intensif, avec l'accroissement du taux de charge et le traitement des pâturages à l'aide de certaines boues que cela implique, peut accroître le risque d'helminthiases gastrointestinales.

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Riassunto La fluttuazione dei livelli di contaminazione dei pascoli erbosi da parte di larve di tricostrongili è dovuta a fattori diversi, fra i quali particolarmente importanti sono il clima ed il tipo di conduzione. Nella pratica, le misure di controllo destinate a proteggere i vitelli da una massiva assunzione di larve si basano sull'analisi particolareggiata dell'andamento del processo di contaminazione dei pascoli erbosi e delle relative conseguenze sul piano epidemiologico. L'introduzione di metodi di allevamento piu intensivi, compresa una maggiore concentrazione dei capi e la fertirrigazione dei pascoli, può aumentare i rischi di insorgenza delle elmintiasi gastrointestinali.

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Virus resistance problems in plant breeding     

K. Björling 《Plant foods for human nutrition (Dordrecht, Netherlands)》1966,13(1-4):330-333

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Effect of freezing and thawing on microbial activity and glyphosate degradation in two Norwegian soils   总被引：2，自引：0，他引：2  

Stenrød M  Eklo OM  Charnay MP  Benoit P 《Pest management science》2005,61(9):887-898

Little research has been done on pesticide dissipation in cold climates and there is a need to focus on the influence of climate on pesticide degradation in soil. Glyphosate, N-(phosphonomethyl)glycine, is a herbicide frequently used for controlling perennial weeds through application after harvest and was used as a model compound for this study. The effect of freeze-thaw activity on the availability of glyphosate in soil, and consequently its mineralization by soil microorganisms, was studied through laboratory incubations of repacked soil cores treated with 14C-labelled glyphosate and subjected to different freeze-thaw treatments. Winter simulation regimes applied were constant thaw (+5 degrees C), constant freezing (-5 degrees C), unstable conditions with short fluctuations (24 h of -5 degrees C followed by 24 h of +5 degrees C), and long duration fluctuations (3 weeks of -5 degrees C followed by 3 weeks of +5 degrees C). Distribution of 14C-glyphosate was followed during the incubation through measurements of the mineralized fraction (14CO2), soil water fraction, KOH extractable fraction, and non-extractable fraction. Microbial parameters used to characterize the soils were estimates of size of microbial biomass, overall microbial activity and microbial diversity. The constant freezing treatment exhibited the lowest amount of glyphosate mineralization. The constant thawed treatment and the treatments with fluctuating temperature exhibited significantly increased mineralization. These results were in accordance with the observed concentration of glyphosate in soil water; the higher the activity, the lower the concentration. The amount of glyphosate extractable with KOH and the resulting non-extractable fraction, however, were not significantly affected by soil type or temperature regime. The glyphosate mineralization pattern was comparable with the overall microbial activity in the soils. Observed different levels of diversity might explain some of the difference in total glyphosate mineralization between soils.  相似文献   

Plasma calcium, inorganic phosphate and magnesium during hypocalcaemia induced by a standardized EDTA infusion in cows     

Mellau LS  Jørgensen RJ  Enemark JM 《Acta veterinaria Scandinavica》2001,42(2):251-260

The intravenous Na2EDTA infusion technique allows effective specific chelation of circulating Ca2+ leading to a progressive hypocalcaemia. Methods previously used were not described in detail and results obtained by monitoring total and free ionic calcium were not comparable due to differences in sampling and analysis. This paper describes a standardized EDTA infusion technique that allowed comparison of the response of calcium, phosphorus and magnesium between 2 groups of experimental cows. The concentration of the Na2EDTA solution was 0.134 mol/l and the flow rate was standardized at 1.2 ml/kg per hour. Involuntary recumbency occurred when ionised calcium dropped to 0.39-0.52 mmol/l due to chelation. An initial fast drop of ionized calcium was observed during the first 20 min of infusion followed by a fluctuation leading to a further drop until recumbency. Pre-infusion [Ca2+] between tests does not correlate with the amount of EDTA required to induce involuntary recumbence. Total calcium concentration measured by atomic absorption remained almost constant during the first 100 min of infusion but declined gradually when the infusion was prolonged. The concentration of inorganic phosphate declined gradually in a fluctuating manner until recumbency. Magnesium concentration remained constant during infusion. Such electrolyte responses during infusion were comparable to those in spontaneous milk fever. The standardized infusion technique might be useful in future experimental studies.  相似文献