We focussed on evaluating the protective effect of lycopene and resveratrol on post-thaw bull sperm and oxidative stress parameters. Nine ejaculates for each bull were used in the study. Each ejaculate, splitted into three equal aliquots and diluted at 37 °C with base extenders containing lycopene (1 × 10(-3)  g ml(-1) ) and resveratrol (1 mm), and no antioxidant (control), was cooled to 5 °C and then frozen. Frozen straws were thawed in a water bath for evaluation. The supplementation of the semen extender with lycopene and resveratrol increased the percentages of post-thawed computer-assisted sperm analysis (CASA) motility (55.8 ± 3.8 and 61.9 ± 4.0%) and progressive motility (38 ± 2.4 and 37 ± 8.8), compared with the controls (50.7 ± 2.65 and 33.3 ± 3.74%, respectively, P < 0.05). Resveratrol provided a higher ALH (4.3 ± 0.1), in comparison with the control (3.9 ± 0.3, P < 0.05). The supplementation of the semen extender with lycopene and resveratrol produced a higher mitochondrial activity (24.6 ± 2.9 and 30.1 ± 6.5% respectively), compared with that of the control (11.8 ± 9.5%, P < 0.05). It was determined that both antioxidants resulted in a lower percentage of sperm with damaged DNA than that of the control (P < 0.05). Sperm motion characteristics except for ALH, acrosome integrity, sperm viability and oxidative stress parameters were not affected by the adding of lycopene and resveratrol.

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The objective was to determine effects of gallic acid (GA) and carnosic acid (CA), present in carob pods and rosemary extract respectively, on frozen-thawed ram spermatozoa. Thirty ejaculates were collected from five Merino rams, pooled, diluted in Tris-based extender and divided into five equal portions containing: 0.05 or 2 mM of GA; 0.05 or 0.2 mM of CA; or no additive (control). Extended semen was equilibrated at +4°C, loaded into straws, held 5 cm above liquid nitrogen for 12 min then plunged.Computer-aided sperm analysis was used to assess motility, whereas flow cytometry

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The objective of this study was to determine effects of supplementing Tris-based semen extenders with either cholesterol-loaded cyclodextrin (CLC) or 7-dehydrocholesterol loaded cyclodextrin (7-DCLC) plus trehalose (T) for cryopreservation of ram semen. Semen was collected with an artificial vagina from five Merino rams (2–3 years of age) during the non-breeding season. Ejaculates were pooled, divided into eight equal portions, diluted with a standard Tris-based extender containing: no additive (control); T (50 mM); or T (50 mM) + 1.5, 2.5 or 3.5 mg of either 7-DCLC or CLC. Semen was chilled from 37°C to 4°C, placed in 0.25 ml French straws, held 5 cm above liquid nitrogen for 12 minutes, then plunged into liquid nitrogen. After thawing, a computer-aided semen analyzer system (CASA) was used to assess motility, whereas plasma membrane and acrosome integrity (PMAI) and high mitochondrial membrane potential (HMMP) were assessed with flow cytometry. Sperm supplemented with 2.5 mg and 3.5 mg CLC + T had the highest (P &lt; 0.05) total and progressive motility (65.2 ± 4.7 and 19.0 ± 1.0% respectively, mean ± SEM), albeit with no significant differences from sperm with 1.5 or 3.5 mg CLC + T. Sperm with 2.5 mg CLC + T had the highest (P &lt; 0.05) PMAI (59.3%; not different from 3.5 mg CLC + T) and highest (P &lt; 0.05) HMMP (64.6%; not different from 1.5 or 3.5 mg CLC + T). The lowest ALH value, 2.8 ± 0.3 µm was in the 2.5 mg 7-DCLC + T group; otherwise, there were no significant differences among groups for any other CASA end point. In conclusion, adding CLC + T to a tris-based extender optimized quality of frozen-thawed ram semen. Therefore, extenders including CLC + T have potential to improve quality of frozen-thawed ram sperm.