Maternal Hydroxytyrosol Supplementation Enhances Antioxidant Capacity and Immunometabolic Adaptations in Nutrient-Restricted Beef Cows and Their Offspring

The impact of maternal dietary restriction and hydroxytyrosol (HT) supplementation during the last third of gestation on plasma malondialdehyde (MDA) concentration, total antioxidant capacity (ABTS assay), and peripheral blood gene expression related to antioxidant defence, immune response, and energy metabolism was evaluated in beef cows and calves. Two feeding treatments in late gestation (T100% vs. T60% of nutrient requirements) and two HT levels (Control vs. HT at 180 mg/kg of diet) were evaluated during gestation (<i>n</i> = 46 cows) and lactation (<i>n</i> = 37 cows and calves). In pregnant cows, undernutrition led to inhibition of glucose oxidation (<i>PDK4</i>), decreased lipid synthesis (<i>HMGCS1</i> and <i>SCD</i>) and TLR signalling; T60% cows showed higher plasma MDA (<i>p</i> < 0.05) with no positive effect of HT on antioxidant capacity. Contrarily, during lactation, earlier HT supplementation upregulated antioxidant capacity and modulated antioxidant gene expression (<i>p</i> < 0.05). In calves, there was an increase in <i>SOD1</i>, <i>CAT</i>, and <i>GPX1</i>, especially in the T60%-HT group (<i>p</i> < 0.05). Interestingly, HT supplementation increased glucose transport (<i>SLC2A1</i>/<i>GLUT1</i>) during pregnancy and lactation (<i>p</i> < 0.05). However, it caused different effects on immunometabolic regulation in both dams and calves, depending on maternal diet. Overall, maternal HT supplementation under restricted nutritional conditions promoted postpartum antioxidant capacity and modulated immune and metabolic gene expression in cows and calves.