Improving Pig Health Through
Genomics
ThePigSite News Desk
October 02, 2008
Health is one of the most important contributors to animal
welfare, productivity and profitability in pig production today.
For the past 30 years, pig breeders have focused on genetic
improvement of lean growth, feed efficiency, meat quality and reproduction. However,
in recent years, selection objectives have been broadened to include livability,
robustness and disease resistance.
A DNA marker for selection of resistance to F18+ E. coli has
been available for several years. This marker decreases mortality and improves
growth on farms experiencing post-weaning scours and/or oedema
disease.
However, for most diseases affecting intensive production
systems such as porcine reproductive and respiratory syndrome (PRRS), porcine circovirus type 2-associated diseases (PCVAD), Haemophilus parasuis and swine
influenza virus, resistance is a complex and polygenic trait. Selection for
improved resistance to these diseases will be incremental and require use of
multiple markers in complex breeding schemes.
Novel technologies such as pig gene microarrays, single
nucleotide polymorphism (SNP) panels and advanced bioinformatics are being used
to identify new health candidate genes for these economically important
diseases.
Lagging behind, however, is availability of large DNA
datasets from pedigreed populations with accurately measured health phenotypes
that are needed to identify associations between SNPs
and health traits. Increased focus on datasets with
health traits will be the key to finding useable discoveries with new genomics
technologies.
Currently, the industry uses dozens of SNP markers to
increase the accuracy of selection for complex breeding objectives, including
disease resistance.
As the pig genome is sequenced and barriers to genotyping
thousand of markers are eliminated, genomic selection for health traits will
receive increasing attention from commercial breeders.
Reference
Mellencamp M.A., Galina-Pantoja L., Gladney C.D. and Torremorell M. (Ralco Nutrition, Inc.,
Marshall, MN 56258, USA). 2008. Developmental Biology (
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