Effects of media and promoters on different lipid peroxidation assays in stallion sperm.

•Lipid peroxidation (LPO) was determined in viable stallion sperm populations.•Milk-based media protected sperm from LPO under promoter-free conditions.•Ultraviolet light promoted sperm LPO in defined and milk-based media.•The study was designed to investigate both early and late stages of sperm LPO.