CRYOPRESERVATION OF ALPACA SPERMATOZOA OBTAINED VIA POST COPULA IN A TRIS EXTENDER WITH EGG YOLK FROM THREE AVIAN SPECIES.

Abstract

The objective of this study was to evaluate the cryopreservation of alpaca spermatozoa obtained via post copula in a Tris extender with egg yolk from three avian species. Forty samples of eight alpacas were collected by the post-copula method. After the collection, we proceeded to evaluate sperm volume, color, motility and concentration. The 25 samples with volume 1 ml and total motility 60% were mixed to form pool (5 samples/pool), divided into three aliquots and diluted in Tris-base with 20% egg yolk from three avian species (hen, quail, paw). These diluted samples were refrigerated for 1,5 h at 5 °C. Once this temperature was reached, the 5% glycerol basic dilutor was added, balanced for 20 min, packed in 0,5 mL straws and frozen in liquid nitrogen vapours for 20 min. The thawed samples were evaluated at different incubation times at 37 °C: 0; 1,5 and 3 h. All parameters of fresh and thawed sperm quality were analyzed using the GLM procedure (ANOVA). The samples collected (fresh) showed a motility of 69,1%, viability of 82,8%, membrane functionality of 77,9% and acrosomal integrity of 85,8%. After the cooling process, no differences were observed between the different egg yolk when comparing the sperm characteristics evaluated (p>0,05). At thawing, motility and acrosomal integrity were superior (p<0,05) when hen and quail were used compared to paw egg yolk. At 1,5 and 3 h of incubation, motility and acrosomal integrity were superior (p<0,05) in the samples with hen and quail with respect to paw. In conclusion, the use of hen and quail provided better cryoprotective action than paw egg yolk in cryopreserved alpaca sperm and incubated at 37°C for 3 h