July 12, 2018

Meat Science and Muscle Biology Symposium

Meat Science and Muscle Biology Symposium: The impact of inflammation and infection on muscle growth, efficiency and meat quality

By: Anne Zinn

The Meat Science and Muscle Biology Symposium was held on Wednesday, July 11 at the ASAS-CSAS Annual Meeting and gave speakers the opportunity to discuss the impact of inflammation and infection on muscle growth, efficiency, and meat quality. Sarah Reed, Assistant Professor at the University of Connecticut, started the afternoon session with a presentation on the roles for inflammation in livestock muscle growth and repair. Reed outlined the importance of efficient muscle growth in livestock and the various intrinsic and environmental factors that can impair prenatal muscle development and postnatal muscle growth. Red then explained that changes in the prenatal (maternal nutrition, heat stress and disease) and the postnatal environments can all increase pro-inflammatory mediators in livestock. Changes in the balance of pro- and anti-inflammatory status during muscle development and/or postnatal growth can negatively impact myoblast proliferation, muscle fiber formation, and hypertrophy. Reed, in collaboration with research completed by Kristen Govoni (UConn) and Steve Zinn (UConn), has spent the past seven years focusing on how maternal nutrition in sheep during maternal gestation alters muscle development and postnatal growth in the offspring, specifically trying to better understand inflammation of muscle tissue as one the mechanisms that causes these changes. Reed emphasized that understanding the impacts of inflammation on myoblast proliferation and differentiation, muscle fiber hypertrophy, and muscle metabolism will allow for improved management techniques and therapeutic interventions. 

Following Reed’s presentation, Anna Dilger, Associate Professor at the University of Illinois, presented on the implications of maternal infection and inflammation for offspring muscle development. Dilger explained that skeletal muscle development during mid-gestation is especially sensitive to the effect of the in utero environment and that appropriate development at this time is crucial for optimal long-term growth. Dilger then outlined researching involving maternal infection and the effects on the offspring, explains that, during gestation, inflammation subsequent to maternal infection can inhibit fetal myogenesis and have long-term effects on offspring growth.  Results demonstrated that infection with porcine respiratory and reproductive syndrome virus during mid-gestation of sows led to dramatic reductions in muscle fiber formation coupled with compensatory modifications in postnatal muscle gene expression and hypertrophy. Additionally, maternal infection and inflammation can alter gene expression. Dilger concluded by explaining that the observed changes suggest that maternal infection and inflammation can alter offspring muscle development and have long-lasting impacts on muscle growth and efficiency of offspring. 

In addition to Reed and Dilger’s presentations, Nicholas Gabler (Associate Professor at Iowa State Unviety) discussed immunometabolism responses to disease in pigs and its impact on feed efficiency, and Casey Maxwell (Associate Advisor, Elanco Animal Health) discussed the effects of disease on growth efficiency and carcass composition of beef cattle.