Epidemiology of fasciolosis on a ranch in the Central Rift Valley,Kenya     

L. W. Wamae  J. O. Ongare  M. A. K. Ihiga  M. Mahaga 《Tropical animal health and production》1990,22(2):132-134

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Ecosystem health as a clinical rotation for senior students in Canadian veterinary schools.   总被引：1，自引：1，他引：0       下载免费PDF全文

C Ribble  B Hunter  N Larivire  D Blanger  G Wobeser  P Y Daoust  T Leighton  D Waltner-Toews  J Davidson  E Spangler    O Nielsen 《The Canadian veterinary journal. La revue veterinaire canadienne》1997,38(8):485-490

We describe 4 years of an experimental rotation in ecosystem health offered to senior veterinary students in Canada. Faculty from the 4 Canadian veterinary colleges collaborated in offering the rotation once annually at 1 of the colleges. The 1st rotation was held in Guelph in 1993, followed in successive years by rotations at Saskatoon, Saint-Hyacinthe, and Charlottetown. The rotation is a predominantly field-based experience that allows students to work with veterinary and other role models who are actively engaged in clinical research related to ecosystem health. Five specific field studies that worked particularly well during the rotations are presented. These studies involved investigating mortality in wildlife due to botulism, designing an environmental surveillance system around herds of beef cattle, using belugas to evaluate the health of the St. Lawrence River, dealing with competition for water use by aquaculture and agriculture, and exploring the role of veterinarians during major coastal oil spills. The experience has resulted in our developing the subject matter, field examples, teaching approach, and confidence necessary to make ecosystem health the focus of a productive clinical rotation for senior year veterinary students.  相似文献   

Chronic eosinophilic leukaemia in blast crisis in a cat negative for feline leukaemia virus     

S R Toth  A S Nash  A M McEwan  O Jarrett 《The Veterinary record》1985,117(18):471-472

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Characterization of circulating antibodies against Chlamydia psittaci in turkeys.     

A E Jensen  A A Andersen  J P Tappe  C O Thoen 《Avian diseases》1990,34(4):878-887

Plasma and joint fluids from turkeys experimentally inoculated with Chlamydia psittaci strain TT3 were evaluated by immunoblotting to identify antibodies elicited by chlamydial antigens during the course of infection. Protein antigens from elementary bodies of TT3 were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred electrophoretically to nitrocellulose before being probed with plasma or synovial fluid from TT3-inoculated birds. The major outer-membrane protein (MOMP), the 60,000-molecular-weight proteins, and a 97,400-molecular-weight protein were the predominant antigens recognized by IgG in the plasma and joint fluids. Plasma IgG specific for the 97,400 protein band was first detectable at day 10 postinoculation (PI). Antibodies to the 60,000-molecular-weight protein and MOMP were first detected at days 14-17 PI and at days 7-10 PI, respectively, in some birds, and as late as days 36-42 PI and days 42-70 PI in others. The antibodies were still present at day 142 PI. Immunoblotting techniques indicated that the antigens to which these antibodies were reacting were protein. These observations may have implications for the development of serodiagnostic assays as well as the identification of potential proteins for subunit immunogens in birds.  相似文献   

Tick-borne diseases of cattle in Paraguay. I. Seroepidemiological studies on anaplasmosis and babesiosis     

R. C. Payne  O. Osorio 《Tropical animal health and production》1990,22(1):53-60

Summary A serological survey was carried out in Paraguay to determine the prevalence of antibodies toAnaplasma marginale, Babesia bigemina andBabesia bovis. The results suggest that the parasites are widely distributed throughout the country with prevalence rates of 9w% forA. marginale, 79% forB. bigemina and 71% forB. bovis. Epidemiological studies on calves demonstrated that initial infection with the three blood parasites occurs in most animals within the first nine months of life. It is likely therefore that most of the country can be considered as being enzootically stable with respect to anaplasmosis and babesiosis.

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Enfermedades Transmitidas For Garrapatas En Paraguay. I. Estudios Seroepidemiologicos De Anaplasmosis Y Babesiosis

Resumen Se llevó a cabo un estudio serológico en el Paraguay, para determinar la prevalencia de anticuerpos deAnaplasma marginale, Babesia bigemina yB. bovis. Los resultados sugieren que los parásitos se encuentran ampliamente distribuidos en todo el país, con tasas de prevalencia de 92% paraA. marginale, 79% paraB. bigemina y 71% paraB. bovis.Los resultados epidemiológicos en terneros demostraron que la infección inicial con los tres parásitos sanguíneos, ocurre durante los primeros nueve meses de vida en la mayoría de ellos. Es possible entonces inferir que la mayoría del país es estable enzoóticamente con respecto a anaplasmosis y babesiosis.

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Maladies Des Bovins Transmises Par Les Tiques Au Paraguay. I. Etudes Seroepidemiologiques Sur l'Anaplasmose Et La Babesiose

Résumé Une enquête sérologique a été réalisée au Paraguay pour déterminer la fréquence des anticorps pourAnaplasma marginale, Babesia bigemina etBabesia bovis. Les résultats indiquent que les parasites sont largement répandus dans tout le pays avec des taux de prévalence de 92% pourA. marginale, 79% pourB. bigemina et 71% pourB. bovis. Les études épidémiologiques réalisées sur des veaux ont démontré que l'infection initiale avec les trois parasites sanguins se produit chez la plupart des animaux durant les neuf premiers mois de la vie. Il est donc vraisemblable que l'on peut considérer la majeure partie du pays comme enzootiquement stable pour ce qui concerne l'anaplasmose et les babésioses.

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Safety and efficacy of two sustained-release intrareticular selenium supplements and the associated placental and colostral transfer of selenium in beef cattle     

D T Campbell  J Maas  D W Weber  O R Hedstrom  B B Norman 《American journal of veterinary research》1990,51(5):813-817

One hundred fifty Se-deficient, pregnant, crossbred beef cows were assigned to 1 of 4 treatment groups: group A, Se-deficient control; group B, 1 Se bolus at 0 and 119 days; group C, 1 Se bolus at 0 days; and group D, 2 Se pellets at 0 days. The Se bolus is an osmotic pump designed to release 3 mg of Se/d into the reticulorumen. The Se pellets weight approximately 30 g and contain 10% elemental Se, which is liberated in the reticulorumen. The Se bolus is designed to provide Se supplementation for 120 days and the Se pellets provide supplementation for up to 18 months. Cattle were maintained on Se-deficient pasture or forages prepared from these pastures for the duration of the experiment. Blood samples were collected from cows prior to treatment (time 0) and at 28, 52, 119, and 220 days thereafter and analyzed for blood Se (BSe) concentration. Body weights were recorded at each sampling time. Blood Se concentration of cows from all supplemented groups were significantly (P less than 0.01) higher than control values at all sample dates after treatments began. By the end of the 220-day study, treatment group-B cattle had significantly (P less than 0.01) higher BSe concentrations than any other group. Body weights of treatment groups fluctuated throughout the study, but did not differ (P greater than 0.05) between groups. One cow and 6 calves born to cows during the experimental period died. Necropsy of 5 calves provided no evidence linking these deaths to treatments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Factors affecting the efficacy of acrolein in irrigation channels in southern Argentina     

D J BENTIVEGNA  & O A FERNÁNDEZ† 《Weed Research》2005,45(4):296-302

Growth of the submerged weed Potamogeton pectinatus L. is a major problem in the irrigation channels located in the Lower Valley of the Colorado River (39°10′–39°55′S; 62°05′–63°55′W) in Argentina. Previous studies indicate that weed control with acrolein is effective in reducing submerged plant biomass. In this study, we evaluated the influence of some variables affecting acrolein and its dissipation in water. Three main parameters, acrolein dosage, the height of the plants and the velocity of water contributed to 80% of the reduction of the submerged weed biomass. Water flow and concentration of the chemical explained 68% of the factors influencing the dissipation of the herbicide. Water velocity, electrical conductivity, pH and the duration of application have a secondary effect in the dissipation process. The constant rate of dissipation (K) was 0.235 L h⁻¹ (SD ±0.125), implying that the chemical will disappear from the system in <24 h. As a practical guideline for the control of mature, dense stands of P. pectinatus within the irrigation system under study, the following conditions are advisable: flow volumes of 500 L s⁻¹ or higher, water velocity of 0.42 m s⁻¹ or more and c. 6.5 mg L⁻¹ concentration of acrolein for at least a 11-h period.  相似文献   

Production and related variables in bovine leukaemia virus-infected cows     

R. M. Jacobs  J. L. Heeney  M. A. Godkin  K. E. Leslie  J. A. Taylor  C. Davies  V. E. O. Valli 《Veterinary research communications》1991,15(6):463-474

A newly developed milk dot blot test was used to detect anti-bovine leukaemia virus (BLV) antibody in milk samples from 2079 lactating adult cows from among 61 herds. The milk dot blot test was highly repeatable; the concordance rate, compared with the agar gel immunodiffusion test performed on serum, was 83.5%. All herds contained BLV-positive cows; the prevalence rate was 36%. BLV-positive cows tended to come from larger herds and were older and more often later in lactation. Fourteen production and related variables (herd size, age, days open, days in milk, milk somatic cell count, milk, fat, and protein produced in the current lactation, projected production of milk, fat, and protein, and breed class average deviations for milk, fat, and protein) were compared between BLV-positive and BLV-negative cows. Although somatic cell count, milk produced, and projected production of milk and protein were related significantly to BLV status using simple tests of association, once the variables herd size, age and days in milk were controlled, these differences were removed. Further analyses using logistic (outcome: individual cow BLV status) and least-squares regression (outcome:herd proportion of BLV-positive cows) failed to show an association between any of the measured production or related variables and BLV-positivity. We concluded that the effect of BLV on production and related variables in dairy cows was below the sensitivity of our analytical techniques or was non-existent.Abbreviations ABCA herd average breed class average for milk, fat, and protein production - AVGAGE average age of the herd - ADIM herd average for days in milk - AGID agar gel immunodiffusion - AVGSCC herd average milk somatic cell count - BCA breed class average, a milk, fat and protein production index calculated by comparing a cow's actual 305-day lactation production to the corresponding BCA standard for the same breed, age, and month of calving - BLV bovine leukaemia virus - CALVINT calving interval - COWAGE cow age - DBCA breed class average deviation for milk, fat, and protein production, the difference between an individual cow's BCA and the herd average - DIM days in milk - HS herd size corresponding to the number of lactating cows in a herd - LACT actual amount of milk, fat, and protein produced in a cow's lactation - ODHIC Ontario Dairy Herd Improvement Corporation - PCTPOS percentage of herd that is BLV-positive - PROJ projected 305-day production for milk, fat, and protein by fitting to a standard lactation curve adjusted for days in milk and age at calving - RHBCA rolling herd average for breed class average for milk, fat, and protein production, the average for all cows that completed a lactation (cows must have completed a 305-day lactation) during the previous 12 months - SCC milk somatic cell count  相似文献   

Larval feeding behaviour of the endangered fish golden bubblebee goodeid, Allotoca dugesi, implications for conservation of an endangered species     

O. DOMÍNGUEZ-DOMÍNGUEZ  S. NANDINI  & S. S. S. SARMA 《Fisheries Management and Ecology》2002,9(5):285-291

Abstract To improve survival of cultured juvenile fishes, it is important to understand prey preferences and predation behaviour of fish larvae. In this study, the feeding behaviour and prey preference of Allotoca dugesi (Bean), a small fish species endemic to Mexico and currently threatened with extinction are presented. Three zooplanktonic prey, viz. Brachionus calyciflorus (Pallas) , Moina macrocopa (Goulden) and Daphnia pulex (Leydig) were tested. The mean size (standard length ± SE, mm) of the larvae ranged from 9.0 ± 0.1 mm at week 1 to 18 ± 2 mm at the end of the experimental period (8 weeks). The gape size (mean ± SE) increased from 0.125 ± 0.002 mm at the first week to 2.300 ± 0.361 mm by the eighth week. Capture success (capture/attack) ranged from 0.80 to 0.98 with Brachionus , 0.72–0.94 with Moina and 0.17–0.46 with Daphnia . Prey preference experiments were conducted using B. calyciflorus, M. macrocopa and D. pulex at a fixed ratio of 5 : 2 : 2 ind. mL⁻¹, respectively, and revealed a positive selection for rotifers and Moina , but avoidance of Daphnia . The results are discussed with reference to conservation efforts for Allotoca dugesi .  相似文献   

Occurrence and treatment of cracked-skull disease affecting Clarias spp. in homestead ponds in Nigeria     

J. N. AWA  W. O. ALEGBELEYE 《Journal of fish diseases》1991,14(4):467-473

Abstract. Cracked-skull disease, previously unrecorded in Nigeria, affected fish in 80% of the homestead ponds investigated in this study. It was peculiar to mud catfish, Clarias spp., under intensive culture in urban Lagos, Nigeria. Male and female fish that were more than 10cm in length were equally vulnerable. The accessory respiratory structures were involved, but the liver, kidney, heart and the other internal organs were not. At its peak, the infection was characterized by a lateral crack in the skull, which resulted in death. Dip treatment in either 2-0ppm potassium permanganate or 0-5ppm formalin (with alcohol) for 30s day ¹resulted in 65-0 and 41-3% full recovery in 7 days, respectively. The implications of the disease for homestead fish culture are discussed.  相似文献