Aiming to evaluate the effect of different concentrations of ethylene glycol or acetamide cryoprotectants on in vitro viability of ram frozen spermatozoa, were used six semen-pools from four Santa Inês crossbred males. After approval, the ejaculate-pool was diluted in Tris egg-yolk plus glycerol (G1=5%; control), ethylene glycol (3%=G2; G3=5%) or acetamide (G4=2%; G5=7%), loaded in straws (0.25mL; 100x106 sperm) and frozeng. Thawed samples (37oC/30 seconds) were evaluated for progressive motility (PM), vigor, plasma membrane integrity (PMi), mitochondrial membrane potential (MMP) and acrosome integrity (ACi). It was found that the PM of G1 was higher (P<0.05) than G3, G4 and G5, and that the vigor of G1, G2 and G3 was higher (P<0.05) than G4 and G5. The PMi of G1 was higher (P<0.05) than G2, G3, G4 and G5, as well as G2 and G3 (P<0.05) where high than G4 and G5. MMP and ACi were not different (P>0.05) among groups. It is concluded that ethylene glycol (3 and 5%) and acetamide (2 and 7%) don't are effectives in protecting ram spermatozoa subjected to freezing.
freezing; cryoprotectants; ram; semen
