The kinetics of goat sperm is negatively affected after freezing in an extender including zinc oxide nanoparticles

BACKGROUND: Nanotechnology can benefit livestock industries, especially through postharvest semen manipulation. Zinc oxide nanoparticles (Np-ZnO) are potentially an example. OBJECTIVE: To investigate how the addition of zinc oxide nanoparticles (Np-ZnO) affected the characteristics of postthawed goat semen. MATERIALS AND METHODS: Seminal pools from four Saanen bucks were used. Semen was diluted in Tris-egg yolk extender, supplemented with Np-ZnO (0, 50, 100 or 200 μg/mL), frozen and stored in liquid nitrogen (−196°C), and thawed in a water bath (37°C/30s). Semen samples were evaluated for sperm kinetics by computer-assisted sperm analysis (CASA), and assessed for other functional properties by epifluorescence microscopy, such as plasma membrane integrity (PMi), acrosomal membrane integrity (ACi) and mitochondrial membrane potential (MMP). RESULTS: For total motility (TM), the group treated with 200 μg/mL Np-ZnO was superior to the control. In straight-line velocity (VSL), the control was better than the group containing 200 μg/mL of Np-ZnO. For average path velocity (VAP), the control was higher than with 100 μg/mL Np-ZnO. For linearity (LIN), the control was higher than with 200 μg/mL Np-ZnO. In straightness (STR), the control and 100 μg/mL Np-ZnO were higher than with 200 μg/mL Np-ZnO. In wobble (WOB), the control was better than the 50 μg/mL Np-ZnO treatment. In PMi, ACi and MMP no significant differences were found. CONCLUSION: The addition of Np-ZnO (200 μg/mL) to the goat semen freezing extender improved the total motility of cells, whilst negatively affecting sperm kinetics.