Ameliorative potential of dietary supplements, ZnO-K, citrus essential oil, and pumpkin seed oil, on sperm quality in Nile tilapia: Insights from CASA, DNA integrity, antioxidant enzymes, and gene expressions

Sperm quality improvement is crucial to achieving the reproductive efficiency of Oreochromis niloticus . This study examined the effect of three dietary antioxidant supplements, kaolinite-doped zinc oxide (ZnO-K), citrus essential oil (CEO), and pumpkin seed oil (PSO), on sperm quality. Integrated sperm examination tools, including Computer Assisted Semen Analysis (CASA) parameters, spermatozoa DNA integrity, antioxidant enzyme bioassays, and gene expressions, were applied to validate sperm quality. One hundred and ninety-two adult males (mean weight 421.31 ± 6.26 g) were divided into four groups, each with three replicates. The first control group was fed on a diet without supplements. The second group was fed on ZnO- K-containing diet (0.06 g kg ^− 1 ); the third group was fed on a CEO-containing diet (10 g kg ^− 1 ); and the fourth group was fed on a PSO-containing diet (15 g kg ^− 1 ). ZnO-K supplementation significantly elevated milt volume (1.40 ± 0.10 ml) and sperm concentration (5.676 x 10 ⁹ sperm ml ^− 1 ), as well as enhancing CASA parameters, including sperm motility, velocities, and DNA integrity. An increase in antioxidant activities of the enzymes, catalase, CAT, glutathione peroxidase, GPX, and superoxide dismutase, SOD, were observed in the ZnO-K-feeding group, recording 47.333 ± 1.452 U ml ^− 1 milt, 65.667 ± 5.547 mU ml ^− 1 milt and 60.667 ± 3.382 U ml ^− 1 milt, respectively. Notably, upregulation of the expressed genes, HSP70 , and CC chemokines was recorded in sperms from ZnO-K- and CEO-feeding groups, compared with gene expression suppression in the PSO-feeding group. All these findings suggest that ZnO-K and CEO are efficient in enhancing the quality of O. niloticus sperm, with the most pronounced effects shown by ZnO-K.