In vitro effects of two different commercial freezing and thawing extenders on boar sperm quality.

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. Ejaculates were collected, diluted (1:1), and cooled before shipping at 17 °C overnight. Samples were aliquoted in cryopreservation extender F1 or F2. 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). The sperm in diluted semen were evaluated for motility kinetics at 30, 180, and 360 min after thawing. The integrity assessments of the plasma and acrosomal membranes were performed at 30 and 360 min after thawing. There was no interaction between F × T × Time (P > 0.05), and no interaction between F × T (P > 0.05). The sperm progressive motility (PMOT) as time post-thawing increased was greater (P = 0.015) when dilutions occurred using F1 compared with F2 extender. Sperm thawed in T1 had a greater TMOT (P = 0.008) and PMOT (P = 0.033) at all times evaluated. The sperm plasma and acrosomal membrane integrity (AIMI) were greater (P = 0.009) when samples were preserved in F1 compared to F2 extender. The use of T2, as compared with T1 thawing extender, resulted in an enhanced integrity of the plasma and acrosomal membranes (P = 0.008). It is concluded different combinations of commercial freezing extenders and thawing solutions have effects on the quality of cryopreserved boar semen in vitro.