TREHALOSE AND A CALCIUM CHELATOR FOR RAM SEMEN CRYOPRESERVATION

Twenty semen samples from ten rams of the Santa Ines breed were cryopreserved with the goal of verifying the effect of trehalose addition (100mOsmol) (group 1 TRIS+TRE) to a Tris-egg yolk-glycerol extender (group 2 TRIS), associated or not to the calcium chelator EDTA (group 3 TRIS+TRE+EDTA), on the post-thaw sperm viability. After evaluation, the diluted semen samples were cooled at 5C and frozen in liquid nitrogen steam. After thawing, the kinetic sperm parameters were analyzed by a computer analyses system (CASA). The sperm viability was observed by using the multiple sperm parameter staining with propidium iodide (PMI, plasmatic membrane integrity), JC1 (MMP, mitochondrial membrane potential) and FITC-PSA (ACI, acrosomal integrity). The statistical analysis was performed using the SAS software, applying the MEANS procedure for descriptive analysis and the GLM procedure with the Student-Newman-Keuls test (SNK) for comparison of sperm parameters among different groups (with P 0.05) among the groups. It can be concluded that the trehalose addition to the TRIS extender, associated or not to EDTA, had detrimental effect on cryosurvival ram sperm.