The study aimed to evaluate the effect of three cryoprotectants: Dimetil Sulfoxide (DMSO), Ethylene glycol (EG) and Glycerol (GL) on the cryopreservation of epididymal alpaca sperm. Testicles of alpacas older than 3 years were used. The epididymides were separated and the tails were dissected. The spermatozoa were recovered with fraction A of the extender (cow skim milk, egg yolk and fructose), selecting samples with sperm motility equal or higher than 50% (n=18, motility = 69%, sperm membrane functional integrity = 48%). The fraction A with the sperm was refrigerated (cooling rate of 1 °C/5 min) until 5 °C. The fraction was divided in three and added the same volume of fraction B with the cryoprotectant (DMSO: 7%, 0.9M; EG: 7%, 0.9M; GL: 7%, 1.2M). Then, 0.5 ml straws were filled with the final dilution and frozen in liquid nitrogen. After 7 days of storage, the post-thaw motilities were 31, 8 and 24% and percentages of sperm membrane functional integrity were 28, 17 and 26% for DMSO, EG and GL respectively. An in vitro fertilization trial was conducted with thawed sperm from groups DMSO and GL, where the cleavage rate at 72 h post-fertilization was 47 and 27% respectively and without statistical difference. The results suggest that dimetil sulfoxide and glycerol are more efficient cryoprotective agents in comparison to the ethylene glycol.
Marino Terreros, C., Wilfredo Huanca, L., Irma Arriaga, C., & Antonio Ampuero, B. (2015). Effect of three cryoprotectans on the cryopreservation of epididymal alpaca spermatozoa. Revista de Investigaciones Veterinarias del Peru, 420-426. https://doi.org/10.15381/rivep.v26i3.11182