Effect of novel lyophilized extenders on stallion post-thaw sperm motility

Abstract

The aim of this study was to assess the effect of lyophilized freezing extenders, which can be stored at roomtemperature, on stallion post-thaw sperm total motility (TM). Ejaculates of 28 stallions were frozen with fourdifferent extenders: two commercial freezing extenders offered worldwide and two novel lyophilized extenders(STAR and MX3), and two different cryopreservation protocols (CP1 with an equilibration period of 20 min. andCP2 with an equilibration period of 60 min.). The TM was assessed after thaw. Mean TM did not show significantdifferences between cryopreservation protocols within each extender. Mean TM was greater in samples dilutedwith STAR than in samples diluted with Botucrio (P ˂ 0.05), but no significant differences were observed for thisvariable between the other studied extenders. From all evaluated samples, twenty ejaculates showed the greatestTM when using the lyophilized extenders and the CP1. Thus, lyophilized extenders are a promising option forstallion sperm cryopreservation and have the advantage of storage and distribution at room temperature for atleast one year.