Utilização da dimetilacetamida e da dimetilformamida associadas ao glicerol para criopreservação do sêmen ovino

Abstract

This work was carried out with the objective of evaluating the effect of dimethylacetamide (DMA) and dimethylformamide (DMF) cryoprotectants, associated or not with glycerol (GL), used in the formulation of diluents for cryopreservation of ovine semen, on in vitro sperm parameters and fertility in vivo. For that, two experiments were carried out with seven treatments each. In the experiment 1 the objective was to evaluate the effect of the use of dimethylacetamide, in different concentrations, associated or not to glycerol, for the preparation of diluents for sperm cryopreservation, on sperm parameters and fertility index of post-thaw sheep semen. The treatments were divided into G1: GLY6%; G2: DMA3%; G3: GLY5% + DMA1%; G4: GLY4% + DMA2%; G5: GLY3% + DMA3%; G6: GLY2% + DMA4% and G7: GLY1% + DMA5%. Experiment 2 had the objective of studying the efficiency of dimethylformamide in different concentrations in the diluents, associated or not to glycerol, for the maintenance of ovine sperm viability in vitro and in vivo after thawing. The groups were divided into G1: GLY6%; G2: DMF3%; G3: GLY5% + DMF1%; G4: GLY4% + DMF2%; G5: GLY3% + DMF3%; G6: GLY2% + DMF4%; G7: GLY1% + DMF5%. Samples from both experiments were evaluated after thawing, for sperm kinetics through computer assisted sperm analysis and membrane integrity by flow cytometry. The results were analyzed through the Statistical Analysis System - SAS with significance level of 5%. No difference (P> 0.05) was observed between the treatments of experiment 1 using DMA in the in vitro and in vivo evaluations. In experiment 2 with DMF, there was difference (P <0.05) in membrane integrity only between G4 and G7, which was not demonstrated in the in vivo test. It was concluded that the cryoprotectants based on dimethylacetamide and dimethylformamide did not differ from glycerol in relation to cryopreservation of ovine semen and could be used as alternative cryoprotectants.