Toward commercialization: Improvement of a semen cryopreservation protocol for European perch enables its implementation for commercial-scale fertilization

Abstract

This study emphasis improved semen cryopreservation protocol for commercial scale fertilization in European perch. The optimized procedure involves a new extender (GM 25 K) containing 0.30 M glucose, 7.5% methanol and 25 mM KCl at 3.0 × 109/mL spermatozoa. The supplementation of glucose-methanol extender with 25 mM KCl enabled high sperm motility (54%) up to 30 min post thawing, showing improvement compared to earlier studies performed on this species. Interestingly, an improved procedure allowed us to handle the semen prediluted in extender up to 30 min and this time period is prerequisite for freezing large volumes of semen at commercial scale. Further, assessment on efficiency of these post-thaw semen showed high fertilization rate for cryopreserved (77.6 ± 14.0) and fresh semen (78.0 ± 14.7; P > 0.05). Cryopreservation of semen performed with improved protocol enables to fertilize up to 237 g of eggs (~118,500 eggs) in a single application which is on commercial scale requirement. Thus, the improved protocol can be implemented to facilitate sustainable commercial scale fertilization toward selective breeding programs of European perch.