Ten sperm samples from 10 healthy and sexually mature Pietráin boars, aged from 9 to 12 months, were used to conduct this study. All boars were submitted to a collection frequency of twice a week using the gloved-hand technique. The semen was filtered through gauze under hygienic conditions to remove the gelatinous fraction. The sperm rich fraction was immediately diluted 1:6 (v:v) in alongterm extender (Duragen®, Magapor, Zaragoza, Spain),divided into 90 mL semen doses and stored at 15–17◦C.One seminal dose was transported refrigerated to the lab-oratory within 24 h post-collection. No fertility problems were previously associated with processing of semen at the AI station.