An imbalance in reactive oxygen species (ROS) levels can lead to oxidative stress (OS), which disrupts embryonic growth in vitro. This study investigated whether supplementing in vitro production media with alpha-lipoic acid (ALA) could reduce OS, enhance embryonic development, and improve the freezing tolerance of bovine embryos. ALA was added at concentrations of 2.5, 5, 10, and 25 μM to either the in vitro maturation (IVM) or in vitro culture (IVC) medium, and its influence on development was examined. We also tested 25 μM ALA added to both IVM and IVC media to evaluate effects on development, embryo quality, ROS balance, and post-thaw survival. Embryos were generated through conventional in vitro techniques. ALA inclusion in IVM or IVC stages did not modify developmental performance or morphology, but it lowered ROS in grade II embryos and increased hatching rates after 12 h on day 7 (grade I) and day 8 (grade II) following thawing. These outcomes indicate that ALA may support early post-warming recovery and metabolic adjustment of embryos.
