METABOLOMIC PROFILING OF BOS TAURUS BEEF, DAIRY AND CROSSBRED CATTLE: A BETWEEN-BREEDS META-ANALYSIS.

Cattle breeds may differ substantially in their metabolism. However, the metabolomes of dairy and beef cattle are not well known. Knowledge of breed-specific metabolic features is essential for biomarker identification and to adopt specific nutritional strategies. The muscle hypertrophy (mh), a beef cattle phenotype present in Asturiana de los Valles (AV) but absent in Asturiana de la Montana (AM) and Holsteins, may underlie such differences. We compared the plasma metabolomes of Holstein, AV, AM and crossbred cattle recipients selected for meta-analysis within an embryo transfer (ET) programme. Blood samples were collected on Day 0 (oestrus) and Day 7 (prior to ET) (N=234 samples x 2 days). Nuclear magnetic resonance quantified N=36 metabolites in plasma, and more metabolic differences between breeds were found on Day 0 (N=19 regulated metabolites) than on Day 7 (N=5). AV and AM largely differed from Holstein cattle (N=55 and N=35 enriched metabolic pathways, respectively); however, AV and AM differed in N=6 enriched pathways. Metabolic activity was higher in AV than in Holstein cattle, as explained in part by the mh phenotype. The metabolomic characterization of breeds facilitates biomarker research and helps to define the healthy ranges of metabolite concentrations.