Metabolomics reveals changes in urea cycle associated to residual feed intake in growing heifers

摘要

Previous studies exploring biomarkers of residual feed intake (RFI) in beef cattle have been conducted on fast-growing males. However, predicting RFI in females is also important because the cowherd represents most of the feeding cost of the overall system. In order to identify candidate biomarkers of RFI in growing females, 48 Charolais heifers with the highest and lowest RFI were selected from 142 individuals to study their blood plasma metabolome through a non-targeted metabolomics approach. The analysis highlighted 147 ions potentially of interest regarding the RFI classes (raw P-values from ANOVA: P<0.1, of which n=74 with _P<0.05). Many of these ions were related directly (ornithine, carbamoyl-P, citrulline) or indirectly (aspartate, lysine, valine) to the urea cycle. Our results suggest that lower intake associated with low RFI led to a lower activity of the urea cycle in efficient growing heifers.