Clostridium tertium as a cause of enteritis in cattle     

Silvera M  Finn B  Reynolds KM  Taylor DJ 《The Veterinary record》2003,153(2):60

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Oxidant stress in sled dogs subjected to repetitive endurance exercise     

Hinchcliff KW  Reinhart GA  DiSilvestro R  Reynolds A  Blostein-Fujii A  Swenson RA 《American journal of veterinary research》2000,61(5):512-517

OBJECTIVE: To determine whether repetitive endurance exercise in sled dogs was associated with substantial lipid peroxidation, decreases in antioxidant capacity of the serum, and skeletal muscle damage. ANIMALS: 24 lightly trained sled dogs. PROCEDURE: 16 dogs completed a 58-km run on each of 3 consecutive days; the other 8 dogs (control) did not exercise during the study. Blood samples were collected before the first exercise run and after the first and third exercise runs. Plasma isoprostane and serum vitamin E concentrations, total antioxidant status of plasma, and serum creatine kinase activity were measured. RESULTS: Plasma isoprostane concentrations in dogs in the exercise group were significantly increased after the first exercise run and further significantly increased after the third exercise run. Serum vitamin E concentration was significantly decreased after the first exercise run in dogs in the exercise group, and this change persisted after the third exercise run. There was a significant linear relationship between plasma isoprostane concentration and the logarithm of serum creatine kinase activity (adjusted ? = 0.84). CONCLUSIONS AND CLINICAL RELEVANCE: Results demonstrate that repetitive endurance exercise in dogs is associated with lipid peroxidation and a reduction in plasma antioxidant concentrations. We interpret these results as indicating that the antioxidant mechanisms of minimally trained dogs may, in some instances, be inadequate to meet the antioxidant requirements of repetitive endurance exercise.  相似文献   

Protective immunity against Newcastle disease: the role of antibodies specific to Newcastle disease virus polypeptides   总被引：3，自引：0，他引：3  

Reynolds DL  Maraqa AD 《Avian diseases》2000,44(1):138-144

Studies were performed to determine if passive immunization with hyperimmune sera generated to specific Newcastle disease virus (NDV) proteins conferred protection against virus challenge. Six groups of 3-wk-old chickens were passively immunized with antiserum against either hemagglutinin-neuraminidase/fusion, (HN/F) protein, nucleoprotein/phosphoprotein (NP/P), Matrix (M) protein, a mixture of all NDV proteins (ALL), intact ultraviolet-inactivated NDV (UVNDV), or negative sera. Blood samples were collected 2 days postimmunization, and the birds were challenged with Texas GB strain of NDV. Antibody titers were detected from those recipient birds that had received the antisera against the HN/F, ALL, or UVNDV by a hemagglutination inhibition test, an enzyme-linked immunosorbent assay (ELISA), and a virus neutralization test. Antibodies were detected only by the ELISA from the birds that had received antisera against NP/P and M protein. Antibody titers in the recipient birds dropped by two dilutions (log2) after 2 days postinjection. Birds passively immunized with antisera against HN/F, ALL, and UVNDV were protected from challenge, whereas chickens passively immunized with antisera against NP/P and M protein and specific-pathogen-free sera developed clinical signs of Newcastle disease. The challenge virus was recovered from the tracheas of all passively immunized groups. The presence of neutralizing antibodies to NDV provided protection from clinical disease but was unable to prevent virus shedding from the trachea.  相似文献   

The fluorescent antibody and indirect fluorescent antibody assays for diagnosing stunting syndrome of turkeys     

Reynolds DL  Oesper J  Ali A 《Avian diseases》2000,44(2):313-317

The fluorescent antibody (FA) assay was developed for detecting the stunting syndrome agent (SSA) from intestinal tissue. Similarly, the indirect fluorescent antibody (IFA) assay was developed for detecting serum antibodies to SSA. Convalescent antiserum from turkeys orally immunized with SSA was found to be the primary antibody of choice for the FA assay. Intestinal jejunal samples from poults inoculated 3-4 days postinoculation (DPI) was found to be the best antigen source for the IFA assay. SSA was detected from the intestinal tracts of experimentally inoculated birds at 2 DPI with highest level of reactivity at 3 DPI by the FA assay. After 4 DPI the level of SSA infectivity of the intestines waned to low levels. Serum antibody was detected from experimentally inoculated birds as early as 7 DPI with all birds tested seroconverting by 12 DPI. These assays should prove useful for future studies concerning stunting syndrome.  相似文献   

The effect of feed intake level on splanchnic metabolism in growing beef steers   总被引：3，自引：0，他引：3  

Lapierre H  Bernier JF  Dubreuil P  Reynolds CK  Farmer C  Ouellet DR  Lobley GE 《Journal of animal science》2000,78(4):1084-1099

The effect of feed intake level (.6, 1.0, and 1.6 x maintenance energy and protein requirements, M) on splanchnic (portal-drained viscera [PDV] plus liver) metabolism was evaluated in six multicatheterized beef steers (398 +/- 27 kg), using a double 3 x 3 Latin square design. On the last day of each 21-d experimental period, six hourly blood samples were collected from arterial, portal, and hepatic vessels. Due to catheter patency, PDV fluxes were measured on five steers, and liver and splanchnic fluxes on four steers. Increasing intake elevated (P < .01) splanchnic release of total (T) amino acids (AA), through increases (P < .01) in PDV release of both essential (E) and nonessential (NE) AA, in spite of a tendency (P < .20) for increased liver removal of NEAA. The PDV release of AA N represented 27 and 51% of digested N for 1.0 and 1.6 x M, respectively. At 1.0 and 1.6 x M, the liver removed 34% of total AA released by the PDV. For individual AA, portal flux of most EAA increased (P < .05) with feed intake, and the increase (P < .10) in splanchnic flux was accompanied by increased arterial concentration for all EAA except histidine, lysine, and methionine. This suggests that these might be limiting AA for this diet. On a net basis, most individual NEAA were released by the PDV except glutamate and glutamine, which were removed by the digestive tract. There was a net removal of NEAA by the liver, except for aspartate and especially glutamate, which were released. Ammonia release by the PDV tended (P < .20) to increase with intake and represented 69, 53, and 45% of digested N at .6, 1.0, and 1.6 x M, respectively. Urea removed by the PDV, unaffected by intake, represented 32, 33, and 21% of the digested N. Arterial glucose concentration increased linearly (P < .01) with greater intake, whereas net liver and splanchnic glucose release increased in a quadratic (P < .05) manner. Net PDV glucose release represented 26% of net glucose hepatic release at 1.6 x M. Intake elevated (P < .10) both insulin and glucagon arterial concentrations, resulting from a larger increment of portal release (P < .01) than hepatic removal (P < .05). Intake-based variations in IGF-I and NEFA arterial concentrations (P < .05) were not related to changes in splanchnic metabolism. These results clearly show the crucial role of the splanchnic tissues in regulating the profile and quantity of AA and concentrations of glucose and pancreatic hormones reaching peripheral tissues.  相似文献   

A sequential study of the pathology associated with the infection of sheep with adult and larval Ostertagia circumcincta     

Scott I  Khalaf S  Simcock DC  Knight CG  Reynolds GW  Pomroy WE  Simpson HV 《Veterinary parasitology》2000,89(1-2):79-94

Disturbances in the physiology of the abomasa of sheep infected with either adult Ostertagia circumcincta given via abomasal cannulae, or larvae (L3) given intraruminally were matched by pathological changes in tissues collected by repeated mucosal biopsy. Within 2-3 days of the transplant of adult worms, abomasal pH had increased markedly in five out of six animals, and there also had been rapid increases in serum gastrin and pepsinogen concentrations in all animals. Reductions in parietal cell number were recorded as early as 1 day after the transplant of adults and were associated with the rapid accumulation of many neutrophils and eosinophils. Mucosal hyperplasia, with increased numbers of cells closer in appearance to mucous/mucous neck cells, was a relatively late development, being most pronounced in the latter part of the infection. In sheep given larvae, changes in secretory physiology were again matched by a concurrent fall in parietal cell number and by the accumulation of inflammatory cells. Changes became maximal when most worms could be expected to be present as adults, confirming the role of adults in the natural disease. Some abnormalities were detected in biopsies collected from animals maintained free of parasites and, although milder in degree, there were similarities to those observed in parasitised tissues, there being fewer parietal cells, a modest degree of mucous cell hyperplasia and inflammatory infiltrates of predominantly neutrophils. These changes were the likely result of trauma to the tissues in the immediate vicinity of the cannula, due either to the presence of the cannula itself or to the frequent collection of biopsy material from areas close to it.  相似文献   

A model of arctic tundra vegetation derived from topographic gradients   总被引：10，自引：0，他引：10  

Ostendorf  Bertram  Reynolds  James F. 《Landscape Ecology》1998,13(3):187-201

We present a topographically-derived vegetation model (TVM) that predicts the landscape patterns of arctic vegetation types in the foothills of the Brooks Range in northern Alaska. In the Arctic there is a strong relationship between water and plant structure and function and TVM is based on the relationships between vegetation types and slope (tan ) and discharge (), two independent variables that can be easily derived from digital terrain data. Both slope and discharge relate to hydrological similarity within a landscape: slope determines the gravitational hydrological gradient and hence influences flow velocity, whereas discharge patterns are computed based on upslope area and quantify lateral flow amount. TVM was developed and parameterized based on vegetation data from a small 2.2 km² watershed and its application was tested in a larger 22km² region. For the watershed, TVM performed quite well, having a high spatial resolution and a goodness-of-fit ranging from 71–78&percnt;, depending on the functions used. For the larger region, the strength of the vegetation types predictions drops somewhat to between 56–59&percnt;. We discuss the various sources of error and limitations of the model for purposes of extrapolation.  相似文献   

Temporal trends in bromide release following rewetting of a naturally drained gully mire     

S. Hughes  B. Reynolds  S. A. Brittain  J. A. Hudson  C. Freeman 《Soil Use and Management》1998,14(4):248-251

Abstract. Recently, there has been interest in the occurrence of bromide (Br^-) in natural waters since it has been demonstrated that Br^-, in association with humic substances in raw waters, is readily incorporated into haloacetic acids in the form of organically bound bromine (Br) during water chlorination. We report results of the effects of experimentally rewetting a naturally drained gully mire on the hydrochemistry of Br^-, iron (Fe) and dissolved organic carbon (DOC) in the peat water. Results obtained over a three year period showed that rewetting substantially increased the concentrations of these solutes in the pore water, with peak values of 1 mg dm^-3 (Br^-), > 60 mg dm^-3 (Fe) and > 300 mg dm^-3 (DOC) detected in some samples after rewetting, compared with typical values < 0.05 mg dm^-3 (Br^-), < 1 mg dm^-3 (Fe) and < 15 mg dm^-3 (DOC) under the drained conditions. Bromide, Fe and DOC release were highly seasonal, with the largest concentrations observed in late-summer to autumn. However, whereas seasonal peak concentrations of Fe and DOC have since remained at these higher levels, seasonal peak concentrations of Br^- were progressively attenuated over time, suggesting the latter phenomenon is a flush effect, with no longer-term consequences for water quality.  相似文献   

Nutritional and economic benefits ofLeucaena andGliricidia as feed supplements for small ruminants in humid West Africa     

M. A. Jabbar  L. Reynolds  A. Larbi  J. Smith 《Tropical animal health and production》1997,29(1):35-47

Summary Considering leguminous trees Leucaenaand Gliricidiaas good sources of quality food, on-station and on-farm studies were conducted in the humid zone of West Africa to establish animal responses to levels, times and forms of browse supplementation, to develop alternative feeding strategies for utilising limited feed supply and to assess the economic benefits of feed supplements as against the use of tree foliage as mulch for crop production. Results indicate that at any level of supplement, sheep grew twice as fast as goats. The main benefits of supplementation came through increased growth and survival. Form and level of supplementation had significant effect on intake. Economic analyses showed that crop response to mulching was the principal competing determinant of whether the use of tree foliage as feed supplement was economic.

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Beneficios Nutricionales Y Economicos De La Utilizacion DeLeucaena YGliricidia Como Suplementos Para Pequenos Rumiantes En Zonas Humedas Del Africa Occidental

Resumen Considerando que los árboles de los génerosLeucaena y Gliricidia son fuentes de alimento de buena calidad, se llevaron a cabo estudios en granjas y estaciones experimentales en zonas húmedas del Africa Occidental para determinar (1) la respuesta de los animales a diferentes niveles, momentos y formas de suplementación, (2) desarrollar estrategias de alimentación alternativas para aprovechar alimentos escasos y (3) determinar los beneficios económicos de la utilización de las hojas de los árboles mencionados como suplemento en lugar de como sistema de protección de los cultivos. Los resultados indicaron que, para cualquier nivel de suplementación, las ovejas crecieron dos veces más deprisa que las cabras. Los principales beneficios de la suplementación fueron un aumento en el crecimiento y en la supervivencia. La forma y el nivel de suplementación tuvieron efectos significativos sobre la ingestión. Los análisis económicos indicaron que la respuesta de los cultivos a la protección con hojas y estiercol fue el pricipal factor a tener en cuenta a la hora de decidir acerca de si la utilización de las hojas como suplemento para el ganado resultaba económica.

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Interets Economiques Et Nutritionnels DeLeucaena EtGliricidia En Tant Qu’Apports Alimentaires Pour Les Petits Ruminants De L’Afrique Humide De l’Ouest

Résumé Considerées comme des sources nutritionnelles de qualité, des études furent menées surLeucaena etGliricidia dans les fermes et les lieux d’élevage dans la zone humide d’Afrique de l’ouest dans le but d’établir les résponses des animaux aux niveaux, durées et formes du broutage, pour développer des stratégies alternatives d’alimentation pour l’utilisation limitée d’apports alimentaires et pour estimer les avantages économiques des suppléments nutritionnels par opposition à l’utilisation de ces legumineuses comme terreau pour la production de récolte. Les resultats montrent que quel que soit le niveau d’apport nutritionnel, la croissance des moutons fut deux fois plus rapide que celle des chèvres. Les principaux intérêts de l’apport nutritionnel résiderent dans l’augmentation de croissance et de la survie des animaux. La nature et le niveau de l’apporteurent un effet significatif sur la consommation. Des analyses économiques montrérent que la résponse des récoltes après apport en terreau fut le principal facteur en compétition d’un point de vue économique, pour l’utilisation de ces légumineuses comme supplément alimentaire.

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Analysis of sawn lumber production from logging residues of branchwood of <Emphasis Type="Italic">Aningeria robusta</Emphasis> and <Emphasis Type="Italic">Terminalia ivorensis</Emphasis>     

Reynolds Okai  Okyere Boateng 《European Journal of Forest Research》2007,126(3):385-390

One way of meeting the supply demands of the wood industry is through the reduction of waste in timber processing. It has been estimated in Ghana that for every tree felled, nearly 50% of the tree volume is left in the forest in the form of branches, crownwood, and stumps. In this study, the potential of utilizing branchwood as raw material from logging residues to help meet the timber demands of the downstream processing sector was analyzed experimentally. The sawing characteristics of the branchwood of Aningeria robusta and Terminalia ivorensis with diameters in the range 10–25 cm using live sawing and cant sawing methods were determined using a randomized complete block design, 2 × 4 factorial with three replications. Experimental results indicate that, the relative lumber value yields for first and second grade boards of A. robusta and T. ivorensis branches were 25 and 20%, respectively, while the green lumber volume yields were 40 and 32%, respectively. A high proportion of sapwood and the occurrence of washboarding in T. ivorensis contributed to that species’ relatively low lumber value and volume yield. The experimental results further indicate that the sawing technique used had no significant influence on lumber yields. However, at 5% level of significance, significant differences in lumber yield existed between some of the diameter classes.  相似文献