Effects of glycerol additions on post-thaw fertility of frozen rainbow trout sperm, with an emphasis on interaction between extender and cryoprotectant

Abstract

The study was conducted to evaluate the effects of different extenders, cryoprotectants and glycerol additions on the postthaw fertility and interactions between extenders and cryoprotectants during cryopreservation. Semen was collected by abdominal stripping from 30 adult male rainbow trout (Oncorhynchus mykiss Walbaum, 1792) and diluted with three different extenders (Erdahl-Graham, Lahnsteiner, glucosebased) containing 15% DMA, 15% DMSO, 15% DMA + 1% glycerol and 15% DMSO + 1% glycerol at a ratio of 1 : 2. Diluted samples were frozen as 0.1 ml pellets directly on dry ice (solid CO 2 , )79°C). Eggs were pooled from 10 females. Fertilization was applied in plastic dishes and 600 eggs were used in each fertilization trial. Pellets were thawed in their own extenders (30°C) at a ratio of 1 : 10. 0.3% NaCl was used for activating motility. Sperm-egg ratio was approximately 3 · 10 6 sp per egg. Experimental success was determined as the percentage of eyed-eggs 25 days after fertilization. The highest eyed-egg rate (49.3%) was obtained from semen frozen with glucose-based extender containing 15% DMSO + 1% glycerol. Our results indicate that the glucose-based extender containing DMSO is a useful combination, but that the addition of glycerol does not have a positive effect on postthaw fertility, and that interaction of the extender-cryoprotectant is also important in the cryopreservation of rainbow trout semen.

Effects of Different Doses of Taurine in the Glucose-Based Extender During Cryopreservation of Rainbow Trout (Oncorhynchus Mykiss) Semen

“…In our study, extender containing glucose (300 mM), which is also used by many researchers (9,26), was applied in the freezing of the rainbow trout sperm. Taurine was used as an antioxidant.…”

Cryopreservation of Brown Trout (Salmo trutta macrostigma) and Ornamental Koi Carp (Cyprinus carpio) Sperm

“…Similarly, addition of optimum amount of cryoprotectant reduces cell damages associated with dehydration, cellular injuries and ice crystal formation (Leung, 1991). Although cryoprotectants help to prevent cryoinjuries during freezing and thawing, they can become toxic to cells when the exposure time and concentration are more (Tekin et al 2007). In addition, type of cryoprotectants is also very specific to many species.…”

Effect of Different Thawing Rates on Motility and Fertilizing Capacity of Cryopreserved Grass Carp (Ctenopharyngodon Idella) Sperm

“…Although methods for sperm cryopreservation have been reported in many fish species, principally in large, commercial species such as salmonids and marine teleosts (5,6,25,27) few studies have addressed this subject to the grass carp (7,30). The availability of a reliable method for cryopreservation of grass carp sperm may help to improve the efficiency of reproductive management in hatcheries.…”

“…Cryopreservation techniques involve addition of cryoprotectants and freezing-thawing of sperm samples, all of which may result in some damage to the spermatozoa and may decrease egg fertilization rates. Furthermore, the methods of fish sperm cryopreservation reveal several common problems such as considerable variability in spermatozoa motility or a wide range of fertility in spermatozoa survival after thawing (28).…”