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Evaluation of cost-effectiveness of targeted sampling methods for detection of Mycobacterium avium subsp paratuberculosis infection in dairy herds
2006
Tavornpanich, S. | Gardner, I.A. | Carpenter, T.E. | Johnson, W.O. | Anderson, R.J.
Objective-To investigate the epidemiologic and financial impacts of targeted sampling of subpopulations of cows, compared with random sampling of all cows, for classification of dairy herd infection status for paratuberculosis. Animals-All cows from 4 infected herds with a low-to-moderate prevalence of paratuberculosis and from 1 noninfected herd in California. Procedure-The infection status of each cow was classified on the basis of results of an ELISA or combined ELISA and fecal culture results. Thirteen sampling schemes designed to randomly sample cows on the basis of lactation number, stage of lactation, and milk production were evaluated. Sampling without replacement was used to obtain a probability of herd detection of paratuberculosis for each evaluated sampling method and for simulated sample sizes between 30 and 150 cows. Marginal cost-effectiveness analysis was used to determine the cost increase relative to the increase in detection probability. Results-Sampling cows in the third or higher lactation and greater than or equal to 200 days into lactation yielded the highest detection probability in most instances, resulting in a detection probability that was 1.4 to 2.5 times that obtained by sampling 30 cows in the second or higher lactation. Costs of testing via the alternative method with a 95% detection probability were approximately $300 lower in a high-prevalence herd (31 %) and $800 lower in a low-prevalence herd (9%), compared with use of the reference method. Conclusions and Clinical Relevance-Detection of herds with paratuberculosis could be improved, and costs of testing substantially reduced by sampling targeted groups of cows.
Afficher plus [+] Moins [-]Evaluation of economic effects and the health and performance of the general cattle population after exposure to cattle persistently infected with bovine viral diarrhea virus in a starter feedlot
2009
To evaluate economic effects and health and performance of the general cattle population after exposure to cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) in a feedlot. 21,743 high-risk calves from the southeastern United States. PI status was determined by use of an antigen-capture ELISA (ACE) and confirmed by use of a second ACE, reverse transcriptase-PCR assay of sera, immunohistochemical analysis, and virus isolation from sera. Groups with various amounts of exposure to BVDV PI cattle were used. After being placed in the feedlot, identified PI cattle were removed from 1 section, but PI cattle remained in another section of the feedlot. Exposure groups for cattle lots arriving without PI animals were determined by spatial association to cattle lots, with PI animals remaining or removed from the lot. 15,348 cattle maintained their exposure group. Performance outcomes improved slightly among the 5 exposure groups as the risk for exposure to BVDV PI cattle decreased. Health outcomes had an association with exposure risk that depended on the exposure group. Comparing cattle lots with direct exposure with those without direct exposure revealed significant improvements in all performance outcomes and in first relapse percentage and mortality percentage in the health outcomes. Economic analysis revealed that fatalities accounted for losses of $5.26/animal and performance losses were $88.26/animal. This study provided evidence that exposure of the general population of feedlot cattle to BVDV PI animals resulted in substantial costs attributable to negative effects on performance and increased fatalities.
Afficher plus [+] Moins [-]CAPRIPOXVIRUS DISEASES IN INDIA
2024
M. R. Omkar | Amitha Reena Gomes | D. Ratnamma | B.M. Chandranaik | G. Sudha
The genus Capripoxvirus (CaPV) comprises three members namely, sheep pox virus (SPPV), goat pox virus (GTPV) and lumpy skin disease virus (LSDV) affecting sheep, goats and cattle, respectively. Capripoxvirus infections produce similar symptoms in sheep and goats, and the three viruses cannot be distinguished serologically. The Capri pox virus disease is an economically important notifiable disease of cattle, sheep and goats (OIE, 2018). This article reviews about the current scenario of Capri pox disease and the better opportunities for prevention and control of disease. Recent outbreaks of the disease have caused the major economic loss in most of the countries including India.
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