ORIGINAL ABSTRACT

Glyphosate (GLP), 2,4-dichlorophenoxyacetic acid (2,4-D), and atrazine (ATZ) are the most commercialized herbicides in Brazil. Despite the damage to male fertility caused by pesticides, information on cattle remains limited. We evaluated the effects of exposing bovine sperm to concentrations of GLP, 2, 4-D, and ATZ. A semen pool from four bulls was incubated at 37°C for 1 and 3 h in TALP-Fert medium, and treated as follows: Control group (vehicle dimethyl sulfoxide); GLP at 5 (G5), 36 (G36), and 50 (G50) µg/mL; 2,4-D, at 0.5 (D05), 1 (D1), and 5 (D5) µM; and ATZ, at 0.05 (A005), 0.1 (A01), and 1 (A1) µM. Herbicide groups affected various kinematic parameters. Total motility was reduced by ATZ, while progressive motility decreased in all treatments compared to the control. Velocity-related kinematic parameters were significantly impaired by GLP treatment, and hyperactivity was negatively influenced by all three herbicide groups. Sperm morphology was altered in the G50, D5, and ATZ groups, with a higher incidence of major defects compared to the control. The hypo-osmotic swelling test revealed that plasma membrane integrity was compromised only in the A005 and A01 treatment groups. Regarding oxidative stress markers, although no differences were observed in reactive oxygen species generation or lipid peroxidation, total antioxidant capacity was significantly reduced by the 2,4-D treatment. Moreover, fertilization rates declined in the D05 group, which corresponded to the lowest 2,4-D concentration. These findings demonstrate that herbicide concentrations can adversely affect bovine spermatozoa by impairing critical quality parameters, ultimately compromising sperm function.