Uso de amidas na criopreservação seminal de galos

Abstract

Although the first semen cryopreservation took place with rooster semen, other species have evolved more in the technique. In addition to the high cost of labor for the collection, processing, and seminal insemination, the semen of roosters is more sensitive than mammals to the cryopreservation process, resulting in reduced fertility. Since glycerol, the main cryoprotectant used in this species, has a contraceptive effect on the female reproductive tract, using alternative cryoprotectants is necessary. To improve the protocols in this species, we tested the amides dimethylacetamide (DMA) and methylformamide (MF) at different concentrations (3%, 6%, 9%, and 12%) in the final extender and balanced with the semen for different periods before freezing (1 min, 3 min, 5 min, 7 min, and 9 min). After thawing, sperm kinetics were evaluated using Computer Assisted Sperm Analysis (CASA) and biochemical and ultrastructural characteristics through flow cytometry. Both amides provided greater protection to the plasma membrane when used at high concentrations, although at these concentrations, motility was reduced. Each amide acted according to its physicochemical characteristics, and the most suitable conditions were: DMA 6% with 3 minutes of equilibrium with the semen and MF 3% with 3 to 7 minutes of equilibrium. Under these conditions, the highest motility was obtained with the least cell damage.