The purpose of the present experiment was to investigate the protective effects of palmitoleate on the quality of ram semen during low temperature liquid storage. Ejaculates were collected using the artificial vagina from four Qezel rams twice a week. Ejaculates were pooled, diluted with Tris-egg yolk extender without palmitoleate (control) or supplemented with 0.125 (P 0.125), 0.25 (P 0.25), 0.5 (P 0.5) and 1 (P 1) mM palmitoleate at a final concentration of 500 × 10 spermatozoa/ml. Total motility and forward progressive motility (FPM) as well as other spermatozoa kinematics were evaluated by computer-assisted sperm analysis. Moreover, viability and membrane functionality were determined in the spermatozoa. Additionally, amounts of malondialdehyde (MDA), total antioxidant activity (AOA), nitric oxide (NO) and superoxide dismutase (SOD) activities were evaluated in the medium and spermatozoa at 0, 24, 48 and 72 hr of storage. The palmitoleate supplementation resulted in a significant (p < .05) increase in total motility and FPM with the highest increase at 0.5 mM concentration for 72 hr. P 0.5 group also resulted in the highest percentage of membrane-intact spermatozoa (76.60 ± 1.95%) and viability (75.81 ± 1.34%) at 72 hr (p < .05). The amounts of MDA and NO were lower in P 0.125, P 0.25 and P 0.5 groups compared to control at 48 hr and 72 hr (p < .05). Higher amounts of AOA were obtained in palmitoleate-treated groups in medium and spermatozoa during storage time (p < .05). Furthermore, palmitoleate supplementation increased the SOD activities in spermatozoa compared to the control (p < .05). The results of the present experiment reveal that supplementation with 0.5 mM palmitoleate improves ram spermatozoa motion characteristics, AOA levels and SOD activities during liquid storage. Then, palmitoleate could be used as an antioxidant source during liquid storage of ram semen.

The present experiment was conducted to evaluate the effect of kinetin on ram semen quality during cold storage. Ejaculates were collected using an artificial vagina from five Qezel rams. Ejaculates which met the criteria (volume of 0.75-2 ml; minimum spermatozoa concentration of 2.5 × 109 spermatozoa/ml and forward progressive motility of 80%), were pooled, diluted with extender without kinetin (control) or enriched with 25 (K 25), 50 (K 50), 100 (K 100) and 200 (K 200) μM kinetin at a final concentration of 500 × 106 spermatozoa per mL. Spermatozoa motion characteristics were evaluated by computer-assisted sperm analysis. In addition, percent of viability (spermatozoa showing no color was considered to be alive) and spermatozoa with intact plasma membrane (spermatozoa with curled/swollen tail was considered healthy) were determined. Moreover, amounts of malondialdehyde (MDA), total antioxidant activity (AOA), nitric oxide (NO) and superoxide dismutase (SOD) activity were determined in the seminal plasma and spermatozoa at 0, 24, 48 and 72 h of storage. Higher percent of total and forward progressive motility was observed in K 25, K 50 and K 100 groups compared to control group at 72 h of storage (P < 0.001). Moreover, K 25 (78.61 ± 1.11%), K 50 (82.46 ± 1.08%) and K 100 (82.96 ± 1.49%) groups showed higher percentage of viability compared to control (72.38 ± 1.49%) at 72 h of storage (P < 0.05). Semen enrichment with kinetin resulted in the higher percent of intact plasma membrane of spermatozoa at 48 and 72 h (P < 0.001). Amounts of MDA were lower and amounts of AOA were higher in K 50 and K 100 groups compared to control at 48 and 72 h (P < 0.05). There were no significant differences in NO levels and SOD activities of seminal plasma and spermatozoa among groups during the experiment. The present experiment revealed that kinetin at proper concentration could enhances spermatozoa kinematics, viability, spermatozoa plasma membrane functionality and amounts of AOA and reduces the level of lipid peroxidation during chilled storage of ram semen.

Current study was carried out to examine the protective effects of quercetin against toxicity induced by hydrogen peroxide in rooster semen in vitro. Semen samples were collected from ten roosters (Ross 308 broiler breeder males, 32 weeks old) twice a week by abdominal massage method. Samples with ≥70% progressive motility were selected, pooled, diluted and used for the study. Experimental groups consisted of negative control, control that received solvent of quercetin, H2O2 (40 μM) and combination groups which incubated with constant dose of H2O2 (40 μM) plus various levels of quercetin (20, 40 and 80 μM). Measurement of total hydroperoxide (HPO), malondialdehyde (MDA), nitric oxide (NO), total antioxidant capacity (TAC) and superoxide dismutase activity as well as routine sperm tests were done at 0, 24 and 48 hr of storage at 4°C. Results revealed that exposure to hydrogen peroxide significantly increased HPO (138.43 ± 7.32 vs. 66.08 ± 3.97 μmol/g protein), MDA (7.21 ± 0.08 vs. 5.71 ± 2.16 μmol/g protein) and NO (0.367 ± 0.013 vs. 0.215 ± 0.011 μmol/g protein) levels and decreased sperm progressive motility (27.28 ± 1.21 vs. 47.49 ± 1.29%), and amounts of TAC (11.49 ± 0.39 vs. 15.70 ± 0.79 mmol/g protein) compared to control at 24 hr (p < 0.05). Changes at mentioned variables were repeated at 48 hr of storage. Also, co‐administration of quercetin (especially at 40 and 80 μM) with hydrogen peroxide restored the toxic effects of hydrogen peroxide on rooster semen parameters such as primary and secondary lipid peroxidative indicators and other evaluated variables. The study concluded that rooster semen enrichment with quercetin would protect lipid peroxidative and nitrosative hydrogen peroxide‐mediated damage during cold liquid storage of rooster semen.

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