Swine Virus and Genes

It's all in the genes.

Genetic Clue for Fighting Swine Virus

By Ann PerryOctober 18, 2007

Agricultural Research Service (ARS) scientists are part of a team that has found a vital clue for battling a disease called porcine reproductive and respiratory syndrome virus (PRRSV), which costs U.S. swine producers about $560 million annually.

PRRSV-infected pigs are susceptible to pneumonia and reproductive losses, and infected sows give birth to weak piglets. It can take weeks or even months for them to recover from the virus, which evolves and adapts quickly to environmental challenges like vaccines and medications.
Scientists Joan Lunney, Patricia Boyd and Daniel Kuhar conduct research at the ARS Animal Parasitic Diseases Laboratory in Beltsville, Md. Working with animal scientist Rodger Johnson and graduate student Derek Petry at the University of Nebraska-Lincoln, they evaluated two lines of swine for genetic resistance to PRRSV. The Nebraska Index line (I) was chosen because of its improved reproductive traits, and the Hampshire by Duroc cross (HD) was selected for its high growth rates.

All pigs in both groups became infected after exposure to PRRSV. However, I pigs generally recovered more quickly, maintained higher levels of weight gain during...(complete article here).

One of the key things that I noticed in this article is that genetic lines that exhibited rapid growth were most susceptible disease. The supposition is that more energy is devoted to growth and less to immune response. By selecting for growth characteristics, we may be sacrificing disease resistance.