Cryopreservation of semen is the most important step for its usage in artificial insemination. Freezing of semen leads to a remarkable reduction in post-thaw semen quality. Therefore, selection of a better semen extender has always been considered priority that could serve as a good cryoprotectant.. Our semen production units (SPUs) have been using Tris based egg yolk semen extender since long time. Some modern SPUs like CEBG are using commercially available semen extenders for better post-thaw semen quality.
After collection pooled semen divided into two equal aliquots in separate sterilized test tubes and kept in water bath at 37 ºC. Semen was diluted with each of extender (TCEY and Triladyl) on the basis of sperm concentration (40x106sperm/ ml). Diluted semen was placed bottles and placed in safety cabinet cooled to 4 ºC over and equilibrated for 4 hrs. After equilibration semen was filled in 0.5 ml French straws (20x106sperm/ 0.5 ml). All semen straws placed in automatic freezer 4cm above liquid nitrogen surface in vapors for 10 minutes. Liquid Nitrogen vapors used in automatic programmable freezer to reduce temperature from 4 ºC to -180 ºC and then plunged into liquid nitrogen -196 ºC for freezing and was stored until analyzed. The experiment was repeated for seven times (replicates = 07)
CASA sperm motility parameter and kinematics were analyzed at Center of Excellence for Bovine Genetics (CEBG) Renala khurd District Okara. For further analysis frozen semen straws were brought to the Department of Theriogenology UVAS, Lahore. Effects of Triladyl and TCEY on post-thaw semen quality of the Nili Ravi buffalo semen were compared.
Summary
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In Triladyl group, significantly (P<0.05) higher post-thaw motility (PTM %), Plasma membrane integrity (PMI, %),) DNA integrity (%), Live percentage was found. However, no significant (P<0.05) difference was found regarding NAR results between both groups. Sperm abnormalities were found significantly lower in Triladyl group as compared to TCEY group.
In overall assessment regarding and post-thaw CASA motility parameters, CASA motility, (PROG %), rapid (RAP %), medium (MED%), and slow (Slow, %) and sperm motility kinematics (VAP μm/sec), (VSL μm/sec), (VCL μm/sec), (ALH μm), (BCF HZ), (STR%) and (LIN%) Triladyl was found better than TCEY.
This was concluded that use of commercial semen extender Triladyl resulted in significantly better post-thaw semen quality as compared to Tris citric egg yolk (TCEY) extender.