| Popis: |
The objective of this study was to verify the efficiency of two different extenders: TRIS/Fructose/Citric Acid/Glycerol (8 %) - (TRIS 8 %) (Morton, 1988 modified) and commercial extender - MP50) (PAPA et al., 2002) – for freezing dog semen. Ten ejaculates from different adult dogs were collected by digital manipulation. The samples semen were evaluated for sperm motility and vigor, hypo-osmotic swelling test, sperm membrane integrity, sperm morphology, ultra structural analysis in three different moments, fresh (T1), cooled (T2) and thawed (T3). The samples were packaged in 0.5 mL French straws with 40 x 106 spermatozoa/ straw, and kept at 5 0C for 60 minutes (T2); then frozen in static vapor of nitrogen for the following 20 minutes and immersed in liquid nitrogen until being thawed in 70 0C water for 8 seconds (T3). By analysis of variance, it would be possible to verify the animal effect on almost all variables observed in this study, except for sperm motility and membrane integrity. For cooled semen (T2), MP50 were significantly better for hypo-osmotic swelling test, sperm membrane integrity (p0,05). A análise ultra-estrutural do sêmen mostrou edema e ondulação da membrana plasmática e acrossomal nas diferentes etapas do processo de criopreservação. Conclui-se que os meios diluentes utilizados mostraram ser semelhantes quanto às características morfofuncionais após a descongelação. PALAVRAS-CHAVE: Cão, congelação, meio diluente, sêmen. |
