Evaluation of the addition of quercetin and vitamin E to the cryopreservation medium of ram semen on in vivo fertility

Cryopreservation induces oxidative stress that has adverse effects on post-thawed semen quality. The objective was to evaluate the effect of adding quercetin to sheep semen cryopreservation medium. Semen was collected from three sheep stallions by artificial vagina, and a commercial diluent was used. Treatments were: control; quercetin 200 mu M; vitamin E 100 mu M; and the quercetin and vitamin E combination. Vitality, motility, acrosome integrity and fertility were evaluated in vivo. Numerical variables were analyzed with ANOVA and gestation rate with chi-square. In the evaluation of sperm motility characteristics, no significant difference was found between treatments. The treatment with the highest percentage of live spermatozoa with intact acrosome was quercetin 200 mu M (22.33 +/- 2.51%) compared to the other treatments (P<0.05). In vivo fertility was not statistically significant, but a numerical difference in the percentage of gestation was found with the addition of 200 mu M quercetin (51.92%) compared to the other treatments. In conclusion, the addition of 200 mu M quercetin to the ovine semen cryopreservation medium improved the vitality and integrity of the acrosome, but not the in vivo fertility percentage.