Recovery and cryopreservation of epididymal sperm from domestic cat using powdered coconut water (ACP-117c) and TRIS extenders.

Cryopreservation of cats epididymal spermatozoa allows the conservation of the genetic material and the study of the cryogenic effect applied to the gametes of other felines. However, this biotechnique still presents variable results, being necessary the investigation of alternative extenders. Powdered coconut water (ACP-117c) has been efficient in the sperm freezing of several species and in the cat sperm refrigeration. Therefore, we aimed to evaluate the effect of the freezing stages and the quality of the cats' epididymal spermatozoa after thawing, using ACP-117c. Epididymides (n = 36) from 18 cats were processed using TRIS (n = 18) or ACP-117c (n = 18) for sperm recovery. The sperm were immediately evaluated. Then, this was cooled, glycerolized, frozen and thawed, and re-evaluated at each stage for sperm kinetics by Computer Assisted Semen Analysis, viability, functionality (HOST), mitochondrial activity (DAB) and morphology. There was a reduction in total motility and progressive motility after thawing in both groups, and TRIS was superior to ACP-117c. The curvilinear velocity reduced after thawing with ACP-117c. Viability decreased after glycerolization in TRIS. Although it also reduced after thawing in both groups, it was higher in TRIS. There was no change on HOST. Mitochondrial activity decreased during the cryopreservation steps for both extenders. Nevertheless, TRIS presented a higher percentage of spermatozoa from DAB class I and II after thawing. Morphology did not differ between extenders. Therefore, ACP-117c is an alternative for the recovery of cat epididymal spermatozoa; however, it is not efficient for freezing. Glycerolization and thawing are the most critical stages, regardless of the extender.

Use of alternative extender added of fructose aiming the cryopreservation of boar semen / Utilização de diluente alternativo acrescido de frutose visando à criopreservação de sêmen suíno

This study aimed to analyze skimmed milk powder (SMP) and fructose in a new cooling curve to freeze boar semen. A total of 49 semen samples from seven boars were cryopreserved using the new curve with addition of glucose and fructose to the refrigerating diluents: Beltsville Thawing Solution (BTS + G; BTS + F) and Skimmed milk powder (SMP + G; SMP + F), totaling four experimental groups for analysis. To finish the curve, aliquots of semen were packaged in 0.5 ml straws and kept in liquid nitrogen. During the cooling curve, SMP mean spermatic vigor and motility were greater than the BTS (p < 0.05). After thawing, a decrease of spermatic force and motility in both extenders was observed, where the BTS presented spermatic vigor (2.1 ± 0.55) and motility (38 ± 21.8), presenting better results (p < 0.05). There was no statistical difference between sugars added to the BTS and SMP in spermatic force and motility (p > 0.05), although the use of fructose allowed an equalization of motility between the SMP and BTS (p > 0.05). Functionality of membrane was better preserved with the addition of fructose, in both extenders. The rate of sperm viability was significantly higher in extender containing glucose and SMP (71.8 ± 12.5). The percentage of intact acrosome was higher on the treatment containing glucose, independent of the extender (BTS + G: 81.8 ± 7.2, SMP + G: 81.4 ± 14.2). To conclude, the results suggest that the BTS is still the best option to cryopreserve and fructose could be used in boar semen cryopreservation in new cooling curve.(AU)

O presente trabalho analisou o emprego do leite em pó desnatado (LPD) adicionado de frutose em uma nova curva de resfriamento para criopreservação de sêmen suíno. Um total de 49 ejaculados, de sete varrões foram criopreservados utilizando a nova curva de resfriamento com glicose e frutose adicionada aos diluentes Beltsville Thawing Solution (BTS + D; BTS + F) e Leite em pó desnatado (LPD + D; LPD + F), totalizando quatro grupos experimentais para análises. Ao final da curva, as alíquotas de sêmen foram envasadas em palhetas de 0,5 mL e mantidas em nitrogênio líquido. Durante a curva de resfriamento, a média de vigor e motilidade espermática do LPD foi maior do que do BTS (p < 0.05). Após descongelação, observou-se queda do vigor e motilidade em ambos diluentes, com o BTS apresentando melhores resultados de vigor (2,1 ± 0,55) e de motilidade (38 ± 21,8) (p < 0,05). Entretanto, o uso da frutose permitiu equiparação dos valores da motilidade entre LPD e BTS (p > 0,05). A funcionalidade de membrana foi melhor preservada com adição da frutose, em ambos os diluentes. Os dados de vitalidade espermática foram significativamente maiores no diluente contendo glicose e LPD (71,8 ± 12,5). A porcentagem de acrossomas intactos foi maior no tratamento que continha glicose, independentemente do diluente utilizado (BTS + G: 81,8 ± 7,2, SMP + G: 81,4 ± 14,2). Os resultados obtidos indicaram que o BTS, ainda é a melhor opção de criopreservação e que a frutose pode ser utilizada para criopreservação de sêmen de varrão na nova curva de resfriamento.(AU)