Effect of Zinc Nano Oxide on the Quality of Turkey Sperm in Liquid State

Background: Over the past two decades, there has been a growing body of research on the effects of nanoparticles on semen parameters.Nanoparticles are molecules with dimensions ranging from 1 to 100 nanometers.Due to their unique properties, nanoparticles have attracted significant attention in biotechnology, medicine, animal reproduction, and veterinary sciences.Their high surface area-to-volume ratio increases reactivity and enhances their ability to penetrate biological tissues.These particles possess high chemical stability, allowing them to remain stable under various environmental conditions, and their nanoscale size enables them to cross biological cell membranes, enhancing cellular efficacy.Zinc is one of the essential elements influencing sperm health.It plays a critical role in sperm viability and motility and affects protein metabolism, nucleic acid synthesis, and sperm membrane stabilization.Most enzymes, including carbonic anhydrase, carboxypeptidase, and superoxide dismutase, require zinc as a cofactor.Zinc's positive effects on semen quality are attributed to its ability to enhance sperm antioxidant capacity, thereby mitigating oxidative stress caused by excessive reactive oxygen species (ROS).ROS are highly reactive, short-lived molecules (10^-9 seconds) derived from oxygen and characterized by one or more unpaired electrons.Due to their unstable chemical nature, they react with nearby organic molecules such as lipids, proteins, and DNA to achieve stability.While controlled ROS production plays a physiological role in key sperm processes-such as motility activation, transient adhesion to the uterine tube, capacitation, increased sperm activity, acrosome reaction, and sperm-oocyte fusion-excessive ROS levels lead to oxidative stress.This stress can cause lipid peroxidation of the sperm's cytoplasmic membrane, acrosomal membrane damage, DNA oxidation and fragmentation, and ultimately chromosomal abnormalities.Zinc helps prevent ROS production and defective sperm and leukocytes.It also exhibits antioxidant effects by inhibiting lipid peroxidation and reducing antisperm antibody levels.Oxidative stress in sperm is associated with accelerated oxidation of cellular components and excessive ROS production.Spermatogenesis occurs in three sequential stages (spermatocytogenesis, spermiogenesis, and spermiation) in the seminiferous tubules.In birds, the duration of spermatogenesis is significantly shorter than in mammals-approximately 25 days.The high content of polyunsaturated fatty acids in avian sperm cell membranes renders them particularly vulnerable to lipid peroxidation.Therefore, maintaining a balance between ROS production and the protective function of the antioxidant system is essential for proper cell function.The predominant polyunsaturated fatty acids in avian sperm membrane phospholipids include arachidonic acid (C20) and docosatetraenoic acid (C22), making the sperm highly susceptible to oxidative damage, which can impair sperm morphology and reduce motility.It is believed that this is a major cause of fertility loss during semen storage in birds.Some metalloenzymes (such as lactate dehydrogenase and sorbitol dehydrogenase), which are important for sperm motility, may contain zinc in their structure.Zinc oxide nanoparticles improve acrosomal membrane integrity, preserve membrane health, enhance acrosomal function, and positively affect mitochondrial performance and its functional integrity.