Effect of glycerol concentration, Equex STM (R) supplementation and liquid storage prior to freezing on the motility and acrosome integrity of frozen-thawed epididymal alpaca (Vicugna pacos) sperm

摘要

Two experiments were conducted to determine the effects of glycerol concentration and apex STM (R) paste on the post-thaw motility and acrosome integrity of epididymal alpaca sperm In Experiment I. epididymal sperm were harvested from male alpacas, diluted, and cooled to 4 degrees C in a Lactose cooling extender, and pellet-frozen in a Lactose cryodiluent containing final glycerol concentrations of 2, 3, or 4% In Experiment 2. epididymal sperm were diluted in Biladyl (R), cooled to 4 degrees C, stored at that temperature for 18-24 h, and further diluted with Biladyl (R) without or with Equex STM (R) paste (final concentration 1% v:v) before pellet freezing In Experiment I. sperm motility was not affected by glycerol concentration immediately (2%. 16 1 +/- 4.6%, 3% 20 5 +/- 5 9% and 4% 18 5 +/- 6 6%, P > 0 05) or 3h post thaw (< 5% for all groups. P > 0.05). Post-thaw acrosome integrity was similar for sperm frozen in 2% (83 6 +/- 1 6%), 3% (81 3 +/- 2.0%) and 4% glycerol (84 8 +/- 2 0%, P > 0 05) but was higher 3h post-thaw for sperm frozen in 3% (75 7 +/- 3 8%) and 4% (77 2 +/- 4.1%) than 2% glycerol (66 9 +/- 2.7%, P < 0 05) In Experiment 2, sperm motility was higher immediately after thawing for sperm frozen in the presence of Equex STM (R) (Equex (R) 21.5 +/- 3 5%, control 14 4 +/- 2 1%, P < 0.05) but was similar at 3h post-thaw (P > 0 05). Acrosome integrity was similar for sperm frozen with or without Equex STM (R) paste immediately (control 89 6 +/- 1 2%, Equex 91.1 +/- 1 4%. P > 0 05) and 3 h post-thaw (control 69 3 +/- 3 7%. Equex (R). 59 9 +/- 5 8%, P > 005). Sperm cryopreserved in medium containing 3-4% glycerol and 1% Equex STM (R) retained the best motility and acrosome integrity, even after liquid storage for 18-24 h at 4 degrees C prior to cryopreservation