The aim of this study was to identify the effects of adding quercetin (Q) to Tris extender in order to identify levels of oxidative stress in bull sperm after freeze thawing. Ejaculates were collected via artificial vagina from Holstein bulls. Semen was divided into five tools and diluted to a final concentration of 15 × 10 spermatozoa/ml with the Tris extender containing Q (25, 50, 100 and 200 μg/ml) and no additive (control; C). All examples were equilibrated at 4°C during 4 hr then were loaded into 0.25-ml straws and frozen using a controlled rate. Sperm motility and motility characteristics were determined using the computer-assisted semen analyser. Sperm membrane integrity was assessed using the hypoosmotic swelling test. Sperm chromatin integrity was investigated using the single cell gel electrophoresis. Total antioxidant capacities were performed colorimetrically. Q supplementation used as an antioxidant did not produce better results in the proportion of sperm progressive and total motility, plasma membrane integrity and sperm abnormalities. Q supplementation exhibited the favourable tail length, tail DNA and tail moment. In conclusion, when whole parameters are considered, Q25 can be added to the Tris extender due to its positive effect on sperm DNA integrity and no adverse effect on the progressive and total motilities of sperm.

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

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 < 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 < 0.05) PMAI (59.3%; not different from 3.5 mg CLC + T) and highest (P < 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.

No abstract

This study aimed to investigate the effectiveness of using red pine bark tree extract (P; Pinus brutia Ten) as a TRIS extender in an attempt to prevent oxidative stress in bull spermatozoa after freezing. Semen specimens were obtained from Simmental bulls via an artificial vagina and pooled. They were separated into five specimens and diluted with Tris extender consisting of P (200, 100, 50 and 25 µg/ml) and P free (control; C) up to a final concentration of 16 × 106 per straw. All specimens were equilibrated for a period of 4 hr at a temperature of 4°C, following which they were filled in 0.25‐ml French straws and frozen. Addition of P resulted in favourable tail length in comparison with C (p < .05). The lowest malondialdehyde levels and the highest glutathione levels were detected in all P groups (p < .05). Supplementation with P did not show advanced results in terms of total, progressive sperm motility and total abnormality in comparison with C (p > .05). In conclusion, it has been shown that although P added to a Tris extender does not have a positive effect on sperm motility, it prevents chromatin damage by reducing oxidative stress, in addition to reducing head abnormalities when used at the amount of 50 μg/ml.