Session: Animal Breeding and Genetics I: Biology of Complex Traits - Disease

14 - Genome-wide Association Studies of Disease Resilience Traits from a Natural Polymicrobial Disease Challenge in Pigs

Thursday, July 15, 2021

9:00 AM – 9:15 AM EST

Location: Kentucky International Convention Center (KICC), M105 & 106

Presenting Author(s)

Jian Cheng, PhD

Postdoc
NC State University
Raleigh, North Carolina

PDF Slides and Audio

Author(s)

RF

Rohan Fernando

Iowa State University
Ames, Iowa
HC

Hao Cheng

University of California, Davis
Davis, California
SK

Stephen D. Kachman

University of Nebraska-Lincoln
Lincoln, Nebraska
KL

KyuSang Lim

Iowa State University
Ames, Iowa
JH

John Harding

University of Saskatchewan
Saskatoon, Saskatchewan
MD

Michael Dyck

University of Alberta
Edmonton, Alberta
FF

Frederic Fortin

Centre de Développement du Porc du Québec Inc
Quebec City, Quebec
GP

Graham Plastow, Ph.D.

Professor and CEO, Livestock Gentec
University of Alberta/Agriculture and Agri-Food Canada
Edmonton, Alberta
Jack C. Dekkers

Professor
Iowa State University
Ames, Iowa

Infectious diseases cause tremendous financial loss in the pork industry, emphasizing the importance of disease resilience, which is the ability of an animal to maintain performance under disease. The objective of this study was to identify quantitative trait loci (QTL) for disease resilience based on both univariate and bivariate genome-wide association studies (GWAS). Data used were late nursery and finisher growth rates and clinical disease phenotypes, including medical treatment and mortality rates, subjective health scores, feed and water intake traits and carcass traits, collected on 50 batches of 60 or 75 crossbred (LRxY) barrows under a polymicrobial natural disease challenge. Multiple QTL were detected for all traits. The major histocompatibility complex (MHC) region (22-25 Mb on chromosome 7) was found to be associated with multiple traits, including late nursery and finisher growth rates, average daily feed intake and intake rate, average daily water dispensed, water intake duration, and number of visits to the drinker. The MHC region explained ~13% of genetic variance for late nursery growth rate. Further fine mapping identified four QTL in the MHC region for late nursery growth rate that spanned the class I, II, and III regions. Gene set enrichment analyses found genomic regions associated with resilience phenotypes to be enriched for previously identified disease susceptibility and immune capacity QTL, for genes that were differentially expressed following bacterial or virus infection and immune response, and for gene ontology terms related to immune and inflammatory response. In conclusion, MHC and other QTL identified play an important role in host response to infectious diseases and can be incorporated in selection to improve disease resilience. Funded by Genome Canada, Genome Alberta, USDA-NIFA, and PigGen Canada.