Search Results (4)

The effect of four extenders on buck semen quality parameters was examined during a 48 h liquid storage. Semen was collected from six Skopelos bucks and diluted in the following extenders, containing: soy lecithin (SL, OviXcell^®), plant phospholipids (PP, AndroMed^®), egg yolk lecithin (EY, Steridyl^®), or no phospholipids (basic extender). Samples were stored at 5 °C for 48 h and assessed at 0, 24 and 48 h for viability (eosin-nigrosin), acrosome integrity (SpermBlue^®), membrane functional integrity (HOST), mitochondrial function (Rhodamine 123/SYBR-14/PI) and motility parameters (CASA). No significant reduction in total or progressive spermatozoa motility and mitochondrial function was observed at 24 h, whereas they all dropped significantly at 48 h, in all extenders. Spermatozoa viability, cell membrane functionality and acrosome integrity dropped progressively (0 h > 24 h > 48 h) in all groups. No significant difference among extenders was observed concerning spermatozoa mitochondrial function. Overall, spermatozoa viability, cell membrane functionality and acrosome integrity were higher in the three commercial extenders, compared to the basic extender. SL and EY extenders (OviXcell^® and Steridyl^®, respectively) preserved viability more effectively than the PP extender (AndroMed^®). Total motility was higher in the PP extender, compared to the SL extender. Spermatozoa acrosome integrity tended to be higher in the EY extender compared to all the other extenders. Further investigation of the protective potential of different types of cryoprotectants on liquid buck semen storage is important. Full article

There are limited studies on the factors affecting the success of ram epididymal spermatozoa (REPS) cryopreservation. On this note, the current study assessed the influence of three commercial soy lecithin-based semen extenders, AndroMed^® (AND), BioXcell^® (BIO), and OviXcell^® (OVI), and two concentrations (400 × 10⁶ vs. 200 × 10⁶ spermatozoa/mL) on the pre-freeze and post-thaw quality of REPS. The REPS were retrieved from nine adult rams’ testes and diluted with each of the three extenders to both concentrations. Straws were frozen manually. Standard motility (SMP) and kinematic parameters (KPs) were assessed via a CASA, while spermatozoa viability, morphology, and acrosomal integrity were assessed via the Kovács–Foote staining technique. The concentration did not significantly affect the pre-freeze and post-thaw SMP and KPs of REPS. BIO and OVI had significantly higher pre-freeze and post-thaw BCFs, post-thaw VAP, and the percentage of all intact heads than AND. In contrast, AND had a significantly lower percentage of REPS with tail defects than BIO and OVI. The 400 × 10⁶ spermatozoa/mL concentration resulted in a significantly higher percentage of all intact heads than the 200 × 10⁶ spermatozoa/mL concentration. Freezing significantly increased tail defects and decreased the percentage of REPS with distal cytoplasmic droplets. The cryopreservation of REPS at the 400 × 10⁶ spermatozoa/mL concentration is recommended. All three extenders must be optimized to preserve the viability, membrane integrity, and better normal morphology of REPS; the reason for increased tail abnormality after the freezing/thawing process needs to be studied. Full article

The supplementation of cryopreservation media with antioxidants improves the post-thaw quality and fertilizing ability of spermatozoa. To maximize the fertility of frozen–thawed buck spermatozoa, further research is required to overcome obstacles that have yielded controversial results and standardize protocols. In the present work, the effect of adding fumaric acid (a well-described antioxidant) to a soy lecithin semen extender on certain quality parameters of spermatozoa following freezing and thawing was examined for the first time. Five sexually mature Skopelos bucks were used, and ejaculates were collected with an artificial vagina. The semen samples (98 samples, five replicates) were diluted (400 × 10⁶ spermatozoa/mL) with OviXcell^®, supplemented with fumaric acid (0 mM, 2.15 mM, 10 mM or 30 mM), equilibrated (5 °C; 3 h), packed (0.5 mL straws), frozen and stored (−196 °C) until further processing. After thawing, the spermatozoa total and progressive motility (CASA), viability (eosin–nigrosin), membrane functional integrity (HOST), acrosome integrity (SpermBlue^®) and mitochondrial function (Rhodamine-123/SYBR-14/PI) were evaluated. Statistical analysis was performed with one-way ANOVA, followed by Duncan’s test; significance was set at 0.05. The addition of 2.15 mM fumaric acid improved (p < 0.05) spermatozoa viability, membrane functional integrity, acrosome integrity and mitochondrial function compared to all other concentrations. The addition of 30 mM fumaric acid decreased (p < 0.05) spermatozoa viability and mitochondrial function compared to all other concentrations. These results indicate a beneficial effect of a 2.15 mM fumaric acid addition to a soy lecithin extender on post-thaw buck spermatozoa quality. Further research is required to evaluate the in vivo fertility of frozen–thawed buck spermatozoa treated with fumaric acid, as well as to elucidate the mechanism of action of fumaric acid in spermatozoa. Full article

This study aimed to evaluate and compare the effect of three semen extenders (S-EXT) on 22 spermatozoa (SPZ) parameters (subjective and computer-assisted sperm analysis evaluations), before and after semen cryopreservation throughout different months of the breeding season in the Portuguese Merino breed. According to the multivariable model, the SPZ viability (alive %), kinetics subjective individual motility, total motility, total progressive motility and its subpopulations, and beat cross frequency) were higher in the egg yolk-based S-EXT improved by Estação Zootécnica National (Portugal) than in Ovixcell^® or Andromed^® extenders. All the differences were only observed in thawed semen, except for total motility and total progressive motility, in which Ovixcell^® also showed the poorest results on fresh semen. An interaction effect between S-EXT and semen processing was observed on 72.3% (17/22) of the evaluated parameters, evidencing a variable cryoprotective action between S-EXT. The SPZ viability was poorer in the onset of the breeding season (end of April/early May) than in the previous middle breeding season (November/early December), suggesting the influence of a short anoestrous season on ejaculate quality, even though the volume and SPZ concentration of the ejaculates remained stable throughout the experiment. Additionally, S-EXT x semen processing x month interaction effect on 59.1% (13/22) of the evaluated parameters evidenced the importance of SPZ time collection in a natural environment to cryopreserve ram’s semen. We concluded that, overall, the egg yolk-based S-EXT provided a greater value to the cryopreservation of Merino rams´ semen. Nevertheless, the causes of the interaction effect between S-EXT, semen processing and/or month on several SPZ parameters should be addressed, including SPZ molecular research in new studies, in order to improve egg yolk-based as well as in egg yolk-free-based S-EXT. Full article