HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) All Versions of this Article: jas.2008-1447v1 87/5/1638    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Doeschl-Wilson, A. B. Articles by Galina-Pantoja, L. Search for Related Content PubMed PubMed Citation Articles by Doeschl-Wilson, A. B. Articles by Galina-Pantoja, L.

Clinical and pathological responses of pigs from two genetically diverse commercial lines to porcine reproductive and respiratory syndrome virus infection

A. B. Doeschl-Wilson^*, I. Kyriazakis, A. Vincent, M. F. Rothschild, E. Thacker and L. Galina-Pantoja^#

^* Scottish Agricultural College, Sustainable Livestock Systems, King’s Buildings, West-Mains Road Edinburgh, EH9 3JG, UK , Faculty of Veterinary Medicine, University of Thessaly, Trikalon 224, GR-43100, Karditsa, Greece , Department of Veterinary Microbiology and Preventive Medecine, Iowa State University, Ames, IA 50011 USA , Department of Animal Science, Center for Integrated Animal Genomics, Iowa State University, Ames, IA 50011 USA ^# Pig Improvement Company, 100 Bluegrass Commons Bldv., Hendersonville, TN 37075, USA

Andrea.Wilson{at}sac.ac.uk

Abstract

The response to infection from porcine reproductive and respiratory syndrome virus (PRRSV) for 2 genetically diverse commercial pig lines was investigated. Seventy two pigs from each line, aged 6 wk, were challenged with PRRSV VR-2385, and 66 littermates served as control. The clinical response to infection was monitored throughout the study and pigs were necropsized at 10 or 21 d post infection. Previous analyses showed significant line differences in susceptibility to PRRSV infection. This study also revealed significant line differences in growth during infection. Line B, characterized by faster growth rate than Line A in the absence of infection, suffered more severe clinical disease and greater reduction in weight growth after infection. Correlations between growth and disease related traits were generally negative, albeit weak. Correlations were also weak amongst most clinical and pathological traits. Clinical disease traits such as respiratory scores and rectal temperatures were poor indicators of virus levels, pathological damage, or growth during PRRSV infection. Relationships between traits varied over time, indicating that different disease related mechanisms may operate at different time scales, and, therefore, that the time of assessing host responses may influence the conclusions drawn about biological significance. Three possible mechanisms underlying growth under PRRSV infection were proposed based on evidence from this and previous studies. It was concluded that a comprehensive framework describing the interaction between the biological mechanisms and the genetic influence on these would be desirable for achieving progress in the genetic control of this economically important disease.

Key Words: genetic susceptibility • pig • porcine reproductive and respiratory syndrome • respiratory disease • response to infection