Volume 7, Issue 3 (May 2005) 7, 303–309; 10.1111/j.1745-7262.2005.00021.x
Effects on the quality of frozen-thawed alpaca (Lama pacos) semen using two different cryoprotectants and extenders
Alexei Santiani, Wilfredo Huanca, Rómulo Sapana, Teodosio Huanca, Néstor Sepúlveda and Raúl Sánchez
1.Veterinary Institute for Tropical and Highland Research, Faculty of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, P.O. Box 03-5034, Lima 41, Perú
2.Quimsachata Experimental Station, National Institute of Agrarian Research, Puno, Perú
3.Reproductive Biotechnology Center, Universidad de La Frontera, P. O. Box 54-D, Temuco, Chile
Received: 2004-07-30 Accepted: 2004-12-13
Aim: To evaluate two extenders and two cryoprotectant agents (CPA) for alpaca semen cryopreservation.
Methods: Semen samples were obtained from four adult alpacas (Lamapacos) and frozen using extender I (TRIS, citrate, egg yolk and glucose) or extender II (skim milk, egg yolk and fructose), each containing either glycerol (G) or ethylene glycol (EG) as CPA. Consequently, four groups were formed: 1) extender I-G; 2) extender I-EG; 3) extender II-G; and 4) extender II-EG. Semen was diluted in a two-step process: for cooling to 5 °C (extenders without CPA), and for freezing (extenders with CPA). Viability and acrosome integrity were assessed using trypan blue and Giemsa stains.
Results: When compared, the motility after thawing was higher (P < 0.05) in groups II-EG (20.0 % ±6.7 %) and II-G (15.3 %± 4.1 %) than that in groups I-G (4.0 % ±1.1 %) and I-EG (1.0 %± 1.4 %). Viable spermatozoa with intact acrosomes in groups II-EG (18.7 % ±2.9 %) and II-G (12.7 % ±5.9 %) were higher than that in groups I-G (5.7 % ±1.5 %) and I-EG (4.0 %±1.0 %).
Conclusion: The skim milk- and egg yolk-based extenders containing ethylene glycol or glycerol to freeze alpaca semen seems to promote the survival of more sperm cells with intact acrosomes than the other extenders.
Keywords: cryopreservation, glycerol, ethylene glycol, extenders, alpaca spermatozoa
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