Establishment a sperm bank of rainbow trout (Onchorhynchus mykiss) breeding from selected farms specific pathogen-free (SPF) in the country through cryopreservation

By broodstocking and propagating of specific pathogen-free (SPF) rainbow trout in Iran, the need to create a cryopreserved sperm bank from the breeders was deemed necessary. In this study, after evaluation of four different extenders for rainbow trout sperm cryopreservation, the best extender (0.6M sucrose and 8% DMSO) has been selected. The sperm samples were obtained from 24 breeders, including four breeders from each of the selected specific pathogen-free farms of the country in Mazandaran and West Azerbaijan provinces (Sarshar, Maroufi, Fakhari, Hadidi, Malekitabar, and Qorbani) were cryopreserved after qualitative evaluation. The fertilization test of sperm samples on the day of sampling and comparison of their fertilization percentage with frozen-thawed sperms in three time intervals (4, 24 and 48 hours) did not show any significant differences between the sperm of the control group and the frozen-thawed samples. The results indicated that the method used in this research can be well used in cryopreservation the sperm of SPF rainbow trout breeders and if needed, the sperm obtained from the best breeders can be transferred to other centers with this method.