The authors reported upregulated expression of genes involved in linoleic metabolism (PLB1 and CYP3A4) and arachidonic acid metabolism (PLB1 and CYP2B6) in the jejunum of the high ADG group, which might explain the higher metabolism and relatively lower plasma concentrations of linoleic acid and arachidonic acid as observed for the HF steers in the current study. This evidence concerns the gene CYP3A4 and hydrops fetalis.