Comparative evaluation of the effect of antioxidants in the conservation of ram semen.

The aim of the present study was to develop a treatment supporting the membrane of ram spermatozoa. Semen of different ejaculates collected from breeding rams was mixed and samples of 10(9) sperm cells per ml and Tris-egg yolk extender were completed with the following antioxidants: alpha-tocopherol acetate (E), glutathione peroxidase (GP), Aromex (AR), resveratrol (R), resveratrol + vitamin E (RE), resveratrol + Aromex (RAR), resveratrol + GP (RGP). Peroxidation was evaluated by the analysis of malondialdehyde (MDA) during incubation for 30, 60 and 120 min at 37 degrees C as well as during a 24-h incubation at 5 degrees C. The success of preservation was checked in a 9-day-long period by observing the acrosomal defects and the motility of spermatozoa. Concentration of MDA was 4.06 nmol/10(9) spermatozoa in samples treated with 15 micrograms R while the control sample contained 69.79 nmol MDA per 10(9) spermatozoa after 24-h incubation. Following 30-, 60- and 120-min storage the concentration of MDA in control and R-treated samples was 25.89, 36.91, 49.57 and 3.69, 3.74, 3.74 nmol/10(9) spermatozoa, respectively. Moreover, a significantly higher proportion of motile sperm cells was observed in the treated than in the control samples. The frequency of acrosomal defects was lower in the treated groups than in the control. These results indicate that RAR treatment can improve the effects of ram semen preservation.