Interpretive Summary: Genetic parameter estimates of liver abscesses in feedlot beef cattle

By: Melanie K Hess, Rebecca L McDermott, Galen E Erickson, Matthew L Spangler

Condemned livers result in over $15M in lost income to the U.S. beef industry annually and the main cause of condemned livers is from abscesses. Liver scoring is a four-level measurement of abscess severity: 0 (no abscesses), A− (mild abscesses), A (moderate abscesses), and A+ (severe abscesses). We explored the sources of variation contributing to liver abscesses including underlying genetic variation in 1,747 feedlot cattle fed a range of diets. Of the sources of variation explored, diet was shown to have a relatively large impact on liver score. Although 10% of the variation in liver score was attributed to the genetic differences among animals there were no SNP identified as playing a large role in liver abscess severity. Liver score was not correlated with hot carcass weight, 12th rib fat, longissimus muscle area, or marbling score. Our results show that genomic selection could be a useful tool, alongside current mitigation strategies such as carefully formulated diets, to reduce the risk of liver abscesses in feedlot cattle without impacting routinely measured carcass traits.

Read the full article in the Journal of Animal Science.