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  • Author or Editor: Bennie I. Osburn x
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Summary

Thirty-two bovine field isolates of bluetongue virus (btv), 6 field isolates of epizootic hemorrhagic disease virus (ehdv) from deer, 4 btv prototype serotypes (10, 11, 13, and 17), and 2 ehdv prototype serotypes (1 and 2) were coelectrophoresed, using polyacrylamide gels. Field isolates were obtained from various regions of the United States. Analysis of polyacrylamide gels and scattered plots generated for comparison of migration patterns for different isolates within each serotype of btv revealed wide variation among the individual segments. The btv serotypes 10 and 11 had more variation, compared with btv serotypes 13 and 17, especially for migration of genome segment 5. A definitive correlation was not seen between the double-stranded rna migration profiles on polyacrylamide gel electrophoresis, geographic origin, herd of origin, or year of collection. One btv field isolate contained more than 1 electropherotype, with 2 bands at the segment-7 position, and it was further characterized as btv serotype 11. Segments 2 and 5 of ehdv isolates were more variable in their migration than were the other gene segments. Generally, migration profiles for ehdv double-stranded rna were more variable, compared with those of btv isolates. Although a correlation was found between migration profiles and serotype of 2 isolates of ehdv, a study of additional ehdv isolates is required before the diversity of electrophoretic patterns of EHDV can be determined.

Free access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

A survey was conducted to assess progress by accredited veterinary medical colleges in the United States and Canada with regard to implementation of recommendations from the North American Veterinary Medical Education Consortium (NAVMEC). Results indicated broad support for many of the recommendations and a willingness among stakeholders in veterinary medical education to accelerate their implementation. Respondents also expressed a desire for evidence-based decisions and detailed implementation planning. Many colleges of veterinary medicine reported progress on initiatives started prior to the meetings of the NAVMEC that closely aligned with NAVMEC recommendations. Only isolated progress toward implementation of system-wide recommendations that required coordination among multiple colleges of veterinary medicine and other stakeholders was identified. Survey results confirmed the need for changes to the current veterinary medical education paradigm and a commitment among many stakeholders to work together to effect these changes.

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in Journal of the American Veterinary Medical Association

Summary

Observations were made on development of diarrhea in special - fed calves (n = 460) on 8 commercial facilities during 2 successive 16-week production cycles at weeks 0, 2, 4, 8, 12, and 16. A total of 23% were affected, with peak number of calves with diarrhea observed at week 0. Suspected enteropathogens were identified in 86 % of these calves, most commonly cryptosporidia, coronavirus, and rotavirus. Identified potential zoonotic pathogens included Giardia and Salmonella spp and verotoxigenic Escherichia coli. Noncytopathic bovine viral diarrhea virus was isolated from 6 calves that had repeated bouts of illness. Only 22% of calves entering the veal facilities had adequate transfer of passive immunity. At week 0, serum IgG concentration in calves that subsequently died or had diarrhea was lower (P < 0.001) than that in healthy calves. All calves that died (n = 6) during the first 4 weeks of production had complete failure of transfer of passive immunity.

Free access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Summary

Results of testing of 19,731 samples from a serologic survey of cattle with bluetongue virus (btv) infections in Australia were analyzed for association between age, species, or sex and test result. Bivariate analysis indicated that all 3 host factors were associated with test result. After adjusting for confounding caused by the location of each animal in the study (high, moderate, and low btv prevalence regions), cattle ≥ 4 years old had an odds ratio of 4.33 (95% confidence interval, 3.99, 4.71) for a positive test result, compared with that for cattle < 2 years old. Cattle 2 to 4 years had an odds ratio of 2.28 (2.14, 2.54), compared with cattle < 2 years old. Bos taurus cattle had an odds ratio of 1.76 (1.63, 2.05) of a positive test result, compared with crossbred cattle, and B indicus cattle had an odds ratio of 1.20 (1.09, 1.33), compared with crossbred cattle. Sexually intact (+) male cattle were found to have an odds ratio of 3.13 (2.66, 3.49) for a positive test result, compared with castrated male (−) cattle, and female cattle were found to have an odds ratio of 1.38 (1.29, 1.48), compared with male (−) cattle.

Multivariate analysis of btv testing results was performed, using stepwise logistic regression. The most parsimonious model selected included age, species, and sex factors, and first-order interaction terms between these factors. This model was only able to be fit to data from cattle restricted to the high (> 25%) btv prevalence region. Odds ratios were found to increase with age for male (−) cattle of all species. Odds ratios were found to be greatest at 2 to 4 years of age for female cattle of all species and for B taurus and crossbred male (+) cattle.

Free access
in American Journal of Veterinary Research