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Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002
Dissertation (MSc (Veterinary Science))--University of Pretoria, 2009.
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University of Pretoria
2013
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| _version_ | 1867613448352825344 |
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| access_status_str | Open Access |
| author2 | Bisschop, Shahn P.R. |
| author_browse | Bisschop, Shahn P.R. |
| author_facet | Bisschop, Shahn P.R. |
| collection | Thesis |
| dc_rights_str_mv | © 2009, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc (Veterinary Science))--University of Pretoria, 2009. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/22859 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:36:18.633Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/22859 Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002 Bisschop, Shahn P.R. Duncan, Neil M. dgbwala@yahoo.com Bwala, Dauda Garba Newcastle disease virus (NDV) Chickens South Africa (SA) UCTD Dissertation (MSc (Veterinary Science))--University of Pretoria, 2009. Since 2002, the South African poultry industry has experienced outbreaks of Newcastle disease (ND) caused by a newly introduced virus (NDV) strain belonging to lineage 5d/VIId (“goose paramyxovirus” - GPMV). Control of the disease has proved difficult with commercially available vaccines appearing ineffective. In the first of two studies, broilers chicks were vaccinated with VG-GA vaccine (lineage II), then challenged with both GPMV and a “classic” challenge virus (RCV) of lineage 3d/VIII to compare the efficacy of the vaccine against both strains. In the second study, commercial and SPF hens in lay were vaccinated with La Sota vaccine and challenged with GPMV isolate, and immunohistochemistry staining used to determine the distribution pattern of viral antigen in the oviduct of the hens. The second study also compared the efficacy of cloacal and ocular routes of vaccination. The first study did not detect any statistically significant difference in protection offered by the vaccine against the GPMV strain in comparison to the RCV strain. The protection offered by the vaccine against challenge with both viruses was found to be dosedependant with 106.0 EID50 producing a 100% protection and 94.44% and 13.89% for 104.5 EID50 and 103.0 EID50 vaccination doses respectively. Protected birds did not manifest clinical signs, but still had macropathological lesions in some organs at necropsy. The computed protective doses (PD50 and PD90) for the VG-GA vaccine were 103.51 and 104.38 for GPMV and 103.79 and 104.43 for RCV. Results from the second study showed no clear difference in the protection of the oviduct from challenge with GPMV by either the cloacal and ocular routes of vaccination. Vaccinated birds were fully protected (100%) against challenge by La Sota vaccine, but not against infection and replication of the virus, as birds showed varying degrees of macropathology with numerous stained viral antigens in the oviducts demonstrated by immunohistochemistry. The susceptibility and colonisation of the oviduct of laying hens by both the lentogenic La Sota and the virulent NDV isolates was confirmed, with the uterus being more susceptible than magnum and isthmus. Necrosis and apoptosis of cells of the oviduct were not detected but cellular infiltration, gland dilatation and interstitial oedema were observed. Production Animal Studies unrestricted 2013-09-06T13:50:57Z 2010-03-12 2013-09-06T13:50:57Z 2009-11-27 2010-03-12 2010-02-26 Dissertation Bwala, DG 2009, Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002, MSc (Veterinary Science) dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/22859 > E10/28/gm http://hdl.handle.net/2263/22859 http://upetd.up.ac.za/thesis/available/etd-02262010-123322/ © 2009, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Newcastle disease virus (NDV) Chickens South Africa (SA) UCTD Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002 |
| title | Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002 |
| title_full | Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002 |
| title_fullStr | Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002 |
| title_full_unstemmed | Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002 |
| title_short | Challenge studies in chickens to evaluate the efficacy of commercial Newcastle disease vaccines against the strains of Newcastle disease virus prevalent in South Africa since 2002 |
| title_sort | challenge studies in chickens to evaluate the efficacy of commercial newcastle disease vaccines against the strains of newcastle disease virus prevalent in south africa since 2002 |
| topic | Newcastle disease virus (NDV) Chickens South Africa (SA) UCTD |
| url | http://hdl.handle.net/2263/22859 http://upetd.up.ac.za/thesis/available/etd-02262010-123322/ |