Effect of Different Extenders and Storage Periods on Motility and Fertilization Rate of Rainbow Trout (Oncorhynchus Mykiss) Semen

The effects of different extenders and storage periods on the motility and fertilization rate of rainbow trout (Oncorhynchus mykiss) semen were evaluated after short-term storage. Semen was collected from anesthetized males by the abdominal massage. After determination of main semen characteristics, the pooled ejaculates were diluted with 4 different extenders at a ratio of 1:3, and stored at 4oC for 72 h. During preservation, spermatozoa motility (%) were determined every 12 h. Fertilization was carried out using the dry fertilization technique. The sperm-egg ratio was approximately 0.5x106 sperm/egg for optimum fertilization success. The highest motility (64.4±5.27%) and fertilization rate (94.3 ± 0.58 %) were obtained from semen stored with glucose based extender after 72 h storage. These results indicate that glucose based extender is a better preservative than the other solutions used in the study for the short term preservation of rainbow trout semen.