Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates

Neospora has become a commonly recognized infectious cause of abortion in dairy cattle. The organism is associated with mid to late term abortion outbreaks with rates exceeding 30% in some herds. Cows infected with this organism exhibit no other clinical signs. While this disease has been reporte...

Full description

Bibliographic Details
Main Author: Murphy, Julia M.
Other Authors: Veterinary Medical Sciences
Format: Others
Published: Virginia Tech 2014
Subjects:
Online Access:http://hdl.handle.net/10919/36843
http://scholar.lib.vt.edu/theses/available/etd-61798-124656/
id ndltd-VTETD-oai-vtechworks.lib.vt.edu-10919-36843
record_format oai_dc
spelling ndltd-VTETD-oai-vtechworks.lib.vt.edu-10919-368432021-10-05T05:39:10Z Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates Murphy, Julia M. Veterinary Medical Sciences Pelzer, Kevin D. Lindsay, David S. Swecker, William S. Jr. Zajac, Anne M. Roberson, Jerry R. veterinary epidemiology ELISA Neospora has become a commonly recognized infectious cause of abortion in dairy cattle. The organism is associated with mid to late term abortion outbreaks with rates exceeding 30% in some herds. Cows infected with this organism exhibit no other clinical signs. While this disease has been reported in other parts of the country, no assessment of Neospora seroprevalence has been undertaken in the Southeast. This study sampled commercial dairy herds to assess Neospora seroprevalence in dairy cows and investigate its significance as an abortifacient agent in Virginia. Twenty four herds participated in the study. Twelve herds had DHIA reported annual abortion rates of 6% or greater (high abortion rate herds) and twelve herds had abortion rates of 2% or less (low abortion rate herds). High abortion rate herds were each paired to a low abortion rate herd (control) herd within the same county. A single blood sample was collected from all cows confirmed to be 90 to 240 days pregnant, with a maximum of thirty samples per herd. A random sample of cows was selected in herds with more than 30 pregnant cows between 90 and 240 days gestation. Neospora antibody titers were determined using a serum ELISA test at the California Veterinary Diagnostic Laboratory. Both mean and median seroprevalence of high and low abortion rate herds were compared using the Mann-Whitney Rank Sum test and the Median test, respectively. No significant difference was found in either case (p=0.56, p=0.41). These findings suggest that Neospora does not contribute significantly to the average abortion rate in Virginia's dairy cattle. Master of Science 2014-03-14T20:51:58Z 2014-03-14T20:51:58Z 1998-06-30 1998-06-30 1999-07-28 1998-07-28 Thesis etd-61798-124656 http://hdl.handle.net/10919/36843 http://scholar.lib.vt.edu/theses/available/etd-61798-124656/ ch1.pdf ch2.pdf In Copyright http://rightsstatements.org/vocab/InC/1.0/ application/pdf application/pdf Virginia Tech
collection NDLTD
format Others
sources NDLTD
topic veterinary epidemiology
ELISA
spellingShingle veterinary epidemiology
ELISA
Murphy, Julia M.
Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates
description Neospora has become a commonly recognized infectious cause of abortion in dairy cattle. The organism is associated with mid to late term abortion outbreaks with rates exceeding 30% in some herds. Cows infected with this organism exhibit no other clinical signs. While this disease has been reported in other parts of the country, no assessment of Neospora seroprevalence has been undertaken in the Southeast. This study sampled commercial dairy herds to assess Neospora seroprevalence in dairy cows and investigate its significance as an abortifacient agent in Virginia. Twenty four herds participated in the study. Twelve herds had DHIA reported annual abortion rates of 6% or greater (high abortion rate herds) and twelve herds had abortion rates of 2% or less (low abortion rate herds). High abortion rate herds were each paired to a low abortion rate herd (control) herd within the same county. A single blood sample was collected from all cows confirmed to be 90 to 240 days pregnant, with a maximum of thirty samples per herd. A random sample of cows was selected in herds with more than 30 pregnant cows between 90 and 240 days gestation. Neospora antibody titers were determined using a serum ELISA test at the California Veterinary Diagnostic Laboratory. Both mean and median seroprevalence of high and low abortion rate herds were compared using the Mann-Whitney Rank Sum test and the Median test, respectively. No significant difference was found in either case (p=0.56, p=0.41). These findings suggest that Neospora does not contribute significantly to the average abortion rate in Virginia's dairy cattle. === Master of Science
author2 Veterinary Medical Sciences
author_facet Veterinary Medical Sciences
Murphy, Julia M.
author Murphy, Julia M.
author_sort Murphy, Julia M.
title Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates
title_short Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates
title_full Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates
title_fullStr Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates
title_full_unstemmed Comparison of Neospora seroprevalence in Virginia dairy herds with high and low abortion rates
title_sort comparison of neospora seroprevalence in virginia dairy herds with high and low abortion rates
publisher Virginia Tech
publishDate 2014
url http://hdl.handle.net/10919/36843
http://scholar.lib.vt.edu/theses/available/etd-61798-124656/
work_keys_str_mv AT murphyjuliam comparisonofneosporaseroprevalenceinvirginiadairyherdswithhighandlowabortionrates
_version_ 1719487407500296192