title: Integrated metabolomic and transcriptome analyses reveal finishing forage affects metabolic pathways related to beef quality and animal welfare.
abstract: Beef represents a major dietary component and source of protein in many countries. With an increasing demand for beef, the industry is currently undergoing changes towards naturally produced beef. However, the true differences between the feeding systems, especially the biochemical and nutritional aspects, are still unclear. Using transcriptome and metabolome profiles, we identified biological pathways related to the differences between grass- and grain-fed Angus steers. In the latissimus dorsi muscle, we have recognized 241 differentially expressed genes (FDR < 0.1). The metabolome examinations of muscle and blood revealed 163 and 179 altered compounds in each tissue (P < 0.05), respectively. Accordingly, alterations in glucose metabolism, divergences in free fatty acids and carnitine conjugated lipid levels, and altered β-oxidation have been observed. The anti-inflammatory n3 polyunsaturated fatty acids are enriched in grass finished beef, while higher levels of n6 PUFAs in grain finished animals may promote inflammation and oxidative stress. Furthermore, grass-fed animals produce tender beef with lower total fat and a higher omega3/omega6 ratio than grain-fed ones, which could potentially benefit consumer health. Most importantly, blood cortisol levels strongly indicate that grass-fed animals may experience less stress than the grain-fed individuals. These results will provide deeper insights into the merits and mechanisms of muscle development.
authors.affiliation: Department of Animal &Avian Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: José A
authors.initials: JA
authors.lastname: Carrillo
authors.affiliation: Department of Animal &Avian Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: Yanghua
authors.initials: Y
authors.lastname: He
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P.R. China, 712100.
authors.forename: Yaokun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Animal &Avian Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: Jianan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Animal &Avian Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Erdman
authors.affiliation: Recombinetics Inc., 1246 University Ave. W, St. Paul, MN 55104, USA.
authors.forename: Tad S
authors.initials: TS
authors.lastname: Sonstegard
authors.affiliation: Department of Animal &Avian Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: Jiuzhou
authors.initials: J
authors.lastname: Song
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000822:Animal Husbandry; D000827:Animal Welfare; D000818:Animals; D001769:Blood / Q000378:metabolism; D002417:Cattle; D020869:Gene Expression Profiling / Q000379:methods*; D008460:Meat / Q000032:analysis; D053858:Metabolic Networks and Pathways; D055432:Metabolomics / Q000379:methods*; D009132:Muscles / Q000378:metabolism; D000069466:Red Meat / Q000032:analysis