Feeding Pinus taeda hydrolyzed lignin to dairy cows during peripartum: effects on health status, milk, and colostrum

. The levels of serum biochemical profile markers remained largely within physiological ranges, indicating no adverse effects on systemic health. Oxyphenol® supplementation was associated with lower serum concentrations of alanine aminotransferase and alkaline phosphatase compared with controls, suggesting a possible modulation of hepatic-related biochemical indicators, although specific markers of liver function and inflammation were not assessed. Parallel reductions in circulating thiobarbituric acid reactive substances indicated alleviation of oxidative-metabolic strain around calving with Oxyphenol® treatment. The antioxidant effect was further supported by lower intracellular reactive oxygen species production and greater viability in peripheral blood mononuclear cells from Oxyphenol® cows, reflecting attenuated oxidative burden at the cellular level. In milk, Oxyphenol® did not affect gross composition, fatty acid profile, or coagulation traits, but increased antioxidant capacity and reduced lipid oxidation products, indicating improved oxidative stability. Colostrum composition was unaffected, though lipid peroxidation markers were reduced. These findings are compatible with improved maternal and mammary redox status; however, direct transfer of phenolic compounds or metabolites into milk and colostrum was not assessed and should be confirmed by targeted metabolomic studies.