![]() ![]() Upon arrival at the laboratory, the average temperature of semen was 18.50 ± 0.09 ☌, total motility was 77.0 ± 0.6%, number of spermatozoa with normal morphology was 90.0 ± 0.4%, and the concentration was 219.5 ± 7.8 × 10 6 spermatozoa/mL. The protocol for use of animals in this experiment Results Animals, semen collection, shipment, freezing and storage The semen freezing and thawing extender, Androstar® CryoPlus and Androstar® Plus, respectively, were also obtained from Minitübe GmbH (Tiefenbach, Germany) while the Minitube Cryoguard and Minitube Cryoguard thawing solutions were obtained from Minitube (Verona, WI, USA). ![]() Pisum sativum agglutinin conjugated to fluorescein isothiocyanate (FITC-PSA), Propidium Iodide (PI), and Hoechst 33342 were obtained from Minitübe GmbH (Tiefenbach, Germany). The aim of this study, therefore, was to determine the effect of using different combinations of commercial freezing extenders (Minitube Cryoguard or Androstar® CryoPlus) and thawing solutions (Minitube Cryoguard Thawing solution or Androstar® Plus) on variables commonly evaluated to estimate the quality of cryopreserved boar semen in vitro. The thawing extender used for increasing the insemination volume, can result in improvements in the morphology and functional characteristics of boar sperm (Knox et al., 2015). Extending the thawed semen is necessary for increasing the volume of the dose used for inseminations in swine (70–100 mL) for traditional transcervical deposition and for deposition of semen in the uterine body (30–50 mL) (Torres et al., 2016a, Ravagnani et al., 2018, Waberski et al., 2019). Thawed boar semen packaged in 5–0.25 mL straw, must be extended before insemination. The effects of these changes, however, are inconsistent, even when commercial solutions are used in cryopreservation and thawing of boar semen (Knox et al., 2015). These include the use of specific fractions of the ejaculate (Saravia et al., 2010, Siqueira et al., 2011), removal or addition of seminal plasma (Okazaki et al., 2009, Torres et al., 2016b), addition of antioxidants (Estrada et al., 2014, Pezo et al., 2021), replacement of lactose (Pezo et al., 2020), as well as, changing holding (Alkmin et al., 2014, Torres et al., 2019) and equilibration times (Passarelli et al., 2020). To improve the fertility of boar sperm, several changes in the cryopreservation regimens have been evaluated. Damage occurs in the acrosome and plasma membranes of the sperm cell, and also impairs sperm motility characteristics (Torres et al., 2016a, Pezo et al., 2020). The cause of the lesser fertility is, in part, due to damage to the structure of boar sperm cells during cryopreservation and thawing processes (Knox, 2015, Yeste et al., 2017). The reason for the infrequent use is that results of numerous studies indicate the use of frozen swine semen results in lesser conception rates and smaller litter sizes. In modern pig production systems, however, there is cryopreserved semen used in only 1% of all artificial inseminations performed (Waberski et al., 2019). It is concluded different combinations of commercial freezing extenders and thawing solutions have effects on the quality of cryopreserved boar semen in vitro.Ĭryopreservation is commonly accepted to be the most suitable biotechnology for long-term storage of boar semen and there can be numerous benefits related to greater biosafety, flexibility of use, and genetic distribution (Knox, 2015, Yeste, 2017). The use of T2, as compared with T1 thawing extender, resulted in an enhanced integrity of the plasma and acrosomal membranes ( P = 0.008). The sperm plasma and acrosomal membrane integrity (AIMI) were greater ( P = 0.009) when samples were preserved in F1 compared to F2 extender. Sperm thawed in T1 had a greater TMOT ( P = 0.008) and PMOT ( P = 0.033) at all times evaluated. The sperm progressive motility (PMOT) as time post-thawing increased was greater ( P = 0.015) when dilutions occurred using F1 compared with F2 extender. There was no interaction between F × T × Time ( P > 0.05), and no interaction between F × T ( P > 0.05). The integrity assessments of the plasma and acrosomal membranes were performed at 30 and 360 min after thawing. The sperm in diluted semen were evaluated for motility kinetics at 30, 180, and 360 min after thawing. Four straws from each treatment sample were thawed and diluted in T1 or T2, resulting in four treatments (F1-T1, F1-T2, F2-T1, and F2-T2). Samples were aliquoted in cryopreservation extender F1 or F2. Ejaculates were collected, diluted (1:1), and cooled before shipping at 17 ☌ overnight. This study was conducted to evaluate whether there were differences in viability of cryopreserved semen when using two different freezing (Minitube Cryoguard – F1 or Androstar® CryoPlus – F2) and thawing (Minitube Cryoguard Thawing solution – T1 or Androstar® Plus – T2) extenders. ![]()
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