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The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows

Dissertation (MSc)--University of Pretoria, 2016.

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Other Authors: Irons, Pete Charles
Format: Thesis
Language:English
Published: University of Pretoria 2017
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access_status_str Open Access
author2 Irons, Pete Charles
author_browse Irons, Pete Charles
author_facet Irons, Pete Charles
collection Thesis
dc_rights_str_mv © 2017 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)--University of Pretoria, 2016.
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institution University of Pretoria (South Africa)
language English
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license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2017
publishDateRange 2017
publishDateSort 2017
publisher University of Pretoria
publisherStr University of Pretoria
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spelling oai:repository.up.ac.za:2263/60272 The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows Irons, Pete Charles u14450756@tuks.co.za Fosgate, Geoffrey Theodore Motimele, Boitumelo UCTD Pregnancy-associated glycoproteins (PAG) Enzyme-Linked Immunosorbent Assay (ELISA) Pregnancy loss Diagnostic validation Ethical clearance Veterinary diagnostics Reproductive performance of dairy herds Veterinary science theses SDG-02 Veterinary science theses SDG-03 Veterinary science theses SDG-09 Veterinary science theses SDG-12 Dissertation (MSc)--University of Pretoria, 2016. The ruminant trophoblast produces pregnancy-associated glycoproteins (BPAGs) starting at day 25 after conception and continuing until parturition. These glycoproteins are detectable in the blood and milk of pregnant females and can be used to diagnose and monitor pregnancy in cattle, small stock and buffaloes. The objective of the study was to estimate the accuracy of three enzyme-linked immune-sorbent assays (ELISA) for BPAGs to diagnose pregnancy in dairy cattle under South African field conditions compared to transrectal ultrasound (TRUS) as a gold standard. A multi-centre prospective study was conducted at five sites in South Africa utilizing the assistance of experienced veterinary practitioners. A total of 1036 plasma and milk samples from dairy cows were analysed. Transrectal ultrasonography was performed immediately after sample collection. The milk and blood samples were analysed with commercial ELISA kits. A total of 532 and 395 cows were found to be pregnant and open, respectively based on ultrasound. The pregnancy rate was 51.4% (532/1036) based on TRUS. Results for sensitivity of ELISA analyses of serum, milk and serum visual ELISA was 99.8%, 99.4%, and 99.6%, respectively. Specificity for the serum, milk and serum visual ELISA was 57.3%, 55.3% and 55.0%, respectively. The results for factors affecting sensitivity and specificity of all the BPAG ELISA analyses (ELISAs) showed that days after AI, breed, DIM and lactation number did not have an effect on sensitivity of any of the BPAG ELISAs. Days after AI and breed influenced the specificity of all the BPAG ELISAs. There was a negative correlation between days after AI and specificity of all the BPAG ELISAs. Specificity decreased gradually as days after AI increased from day 28 to 35. Additionally, pregnancy loss influenced the specificity of the three BPAG ELISAs from 28 to 35 days after AI. In conclusion, the BPAG ELISAs were sensitive tests for detecting pregnancy relative to TRUS B from days 28-35 and 42-49 d after breeding but poorly specific in identifying non-pregnant cows. The specificity estimates were under-estimated due to the incidence of pregnancy loss during early gestation. es2025 Production Animal Studies MSc Unrestricted SDG-02: Zero hunger SDG-03: Good health and well-being SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production 2017-05-08T10:06:15Z 2017-05-08T10:06:15Z 2017-04-07 2016 Dissertation Motimele, B 2016, The sensitivity and specificity of three pregnancy-associated glycoprotein ELISAs and factors affecting test accuracy in South African dairy herds, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/60272> A2017 http://hdl.handle.net/2263/60272 en © 2017 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 UCTD
Pregnancy-associated glycoproteins (PAG)
Enzyme-Linked Immunosorbent Assay (ELISA)
Pregnancy loss
Diagnostic validation
Ethical clearance
Veterinary diagnostics
Reproductive performance of dairy herds
Veterinary science theses SDG-02
Veterinary science theses SDG-03
Veterinary science theses SDG-09
Veterinary science theses SDG-12
The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows
title The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows
title_full The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows
title_fullStr The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows
title_full_unstemmed The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows
title_short The sensitivity and specificity of three pregnancy-associated glycoprotein ELISA assays and factors affecting test accuracy in South African dairy cows
title_sort sensitivity and specificity of three pregnancy associated glycoprotein elisa assays and factors affecting test accuracy in south african dairy cows
topic UCTD
Pregnancy-associated glycoproteins (PAG)
Enzyme-Linked Immunosorbent Assay (ELISA)
Pregnancy loss
Diagnostic validation
Ethical clearance
Veterinary diagnostics
Reproductive performance of dairy herds
Veterinary science theses SDG-02
Veterinary science theses SDG-03
Veterinary science theses SDG-09
Veterinary science theses SDG-12
url http://hdl.handle.net/2263/60272