Zinc Nanoparticles ameliorated heat stress impacts, improved semen characteristics, and preserved normal antioxidant status and hepatic-renal functions in goat-bucks

Background
Zinc nanoparticles have several medical and biomedical applications in livestock because of their antioxidant and antimicrobial properties. Aims: To improve the reproductive capacity of native male goats during months of heat stress. Material and methods: Goat bucks used in the current work (n=8) were divided into control (0.0 mg zinc nanoparticles) and zinc nanoparticles (50.0mg/daily ZnONPs) groups. For 49 days, semen and blood samples were collected during the cold months (Day -42) and at biweekly intervals from the start of the supplementation (heat stress)until 60 days. Sperm mass and individual motilities, live sperm percent, sperm cell concentration, and plasma membrane integrity percent (hypo-osmotic swelling test, HOST) were determined for each animal in the control and treated groups. Malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase, total proteins, albumin, globulin, creatinine, aspartate transaminase (AST), and alanine transaminase (ALT) were measured in the blood samples. Results: ZnONPs synthesized by the green method using thyme aqueous extract were amorphous and had a diameter of <20nm. Compared to the control, the sperm mass motility of the ZnONPs group increased on Days 15 (P<0.001), 45 (P<0.05), and 60 (P<0.001). The progressive sperm motility of the ZnONPs group was higher than controls on Days -42-30 (P<0.05) and 45-60 (P<0.001). Live sperm %and sperm cell concentrations of ZnONPs group increased (P<0.001) throughout the experiment compared to controls. The number of HOSTs of ZnONPs increased on Days 15-30 (P<0.05) and days 45-60 (P<0.001). Malondialdehyde of supplemented bucks were lower than controls on days -42 (P<0.01), 15-30 (P<0.01), and 60 (P<0.01). The total antioxidant capacity of intreated bucks was higher than that of the controls on Day 30 (P<0.01). Higher SOD activity of treated bucks was observed on Days -42, 15 (P<0.01), and 60. The catalase activity of treated bucks was lower than that of controls on days 30 (P<0.05), 45, and 60 (P<0.0001). Total proteins and globulins of treated bucks showed lower concentrations than controls but higher albumin except on day 15 for total proteins and day 60 for albumin. Lower creatinine levels were observed in treated bucks on days 45 and 60. Slightly higher AST and ALT (P>0.05) were observed in treated bucks on Day 15. Conclusions: The recommended daily allowance of ZnONPs improved semen characteristics, reduced oxidative stress, improved total antioxidant status, and preserved normal hepatic and renal functions.