The effects of ex vivo cold-storage on cryopreservation of the goat (Caprus hircus) epididymal sperm

BACKGROUND There are many studies focused on long or short storage time of epididymal sperm (EPS) of different species. There are limited studies on preservation or cryopreservation of the domestic goat EPS. OBJECTIVE The aim of the present study was to evaluate the effects of ex vivo cold-storage on freezing of EPS from goat (Capra hircus). MATERIALS AND METHODS In a split-plot design the caprine testes-epididymides (40 pairs) were divided to 4 storage-time groups equally (0, 24, 48 and 72 h), then subjected to cryopreservation using Bioxell. Sperm parameters were analyzed before and after freezing. RESULTS Duration of cold-storage as well as freezing at all storage-time points reduced sperm viability and progressive motility while increased sperm tail abnormalities (p<0.0001). Freezing reduced the percentage of cytoplasmic droplets (p<0.0001). The percentage of detached heads was increased at all storage-time points following freezing (p=0.0019), except at time 0 h. CONCLUSION It can be concluded that cold storage [in refrigerator (4(o)C) for 72 h] of epididymides efficiently protected the goat EPS in terms of progressive motility and viability. However, cold-storage may not protect the goat EPS against cryopreservation with Bioxell.