In vitro evaluation of ram sperm frozen with glycerol, ethylene glycol or acetamide

Crude glycerol negatively affects rabbit spermatozoa motility in vitro

“…García et al (2012) observed a pronounced toxicity of ≥ 3.5% glycerol on stallion spermatozoa in vitro, with the maximal toxicity at 5% glycerol. Compared to our results it can be speculated that the toxicity of a glycerol concentration is species-dependent, supported by findings of Silva et al (2012), where 5% glycerol still protected frozen-thawed ram spermatozoa against loss of progressive motility. It is generally accepted that the toxicity of cryopermeating agents such as glycerol strongly correlates with increasing concentration and exposure time, as there is time latency for glycerol to permeate spermatozoa and reach equilibrium between extracellular and intracellular environment.…”

Ethylene glycol, but not DMSO, could replace glycerol inclusion in soybean lecithin-based extenders in ram sperm cryopreservation

“…Silva et al (2012), found that the addition of 3% to 5% ethylene glycol in freezing media protects post-thaw ram sperm motility similar to findings with the control group (glycerol), but the study was conducted using egg yolk instead of soybean lecithin. Although glycerol is the first and most commonly used cryoprotectant for semen freezing media (Nur et al, 2010), it's use decreases the quality and fertilizing capacity of semen (Pontbriand et al, 1989;Abdelhakeam et al, 1991).…”

“…Based on results of the present study, the lesser percentage of plasma membrane integrity is associated with a lesser percentage of live sperm. Silva et al (2012), demonstrated that treatment with 5% glycerol as well as 3% and 5% ethylene glycol protected ram sperm against the adverse effects of freezing and that 5% glycerol had a greater protection capacity for the sperm plasma membrane. Results of the present study demonstrated that significant damage to plasma membranes occurred during the freezing and thawing sperm using different concentrations of DMSO.…”

“…Low temperatures result in subjecting gametes to atypical stress, which decreases the viability, functionality and fertilizing capacity of sperm (Salamon and Maxwell, 2000;Silva et al, 2012). To reduce or prevent the injuries caused by low temperature, it is essential to add substances that provide the sperm with cryoprotection.…”

Olive oil as an alternative to boar semen cryopreservation

“…Semen is a biological sample with large variation, since hardly showed normal distribution in various evaluations of seminal quality 43,44,45,46 and that increased sampling contributes to decrease variability 47 . Thus, it is believed that increasing the sampling demonstrate the differences statistically between treatments containing olive oil and control because many experiments assessing sperm quality with larger samples obtained superior results in the treated groups 24,33,48 .…”