Efecto de la jalea real sobre la capacidad fecundante in vitro de espermatozoides bovinos congelados y vitrificados

Abstract

Royal jelly (RJ) is a product secreted by the cephalic glands of nurse bees that, due to its powerful protein and antioxidant composition, has been used in the cryopreservation of spermatozoa. In this regard, this study evaluated the effect of royal jelly on the in vitro fertilizing (IVF) ability of frozen and vitrified bovine spermatozoa. Four treatments were evaluated based on the supplementation with RJ (0 [control] and 0.12% w/v) and the type of cryopreservation (conventional freezing [CF] and vitrification [VIT]): CC-JR (n=80 straws); CC-Co (n=80 straws); VIT-JR (n=20 cryotubes), and VIT-Co (n=20 cryotubes). Each treatment was objectively evaluated for its kinematics and fertilizing capacity using a CASA system (SCA®) and in vitro fertilization (200 oocytes/treatment), respectively. The results showed higher post-cryopreservation kinematics (P < 0.05) with the freezing treatments (CC- JR and CC-Co) than with the vitrification treatments (VIT-JR and VIT-Co). The CC-RJ treatment produced higher (P<0.05) curvilinear velocity (VCL) and straight-line velocity (VSL), and beat cross frequency (BCF) than the CC-Co treatment, while the VIT-JR treatment only produced higher (P<0.05) BCF compared to its control VIT-Co. The VIT-JR treatment produced a higher (P<0.05) cleavage rate (%) than the CC-Co treatment (62.9±3.53 vs. 51.7±3.25, respectively). However, the blastocyst rate (%) at 7 days after IVF did not differ (P>0.05) among treatments: CC-JR: 9.66±2.74; CC- Co: 11.03±2.45; VIT-JR: 8.82±2.54; and VIT-Co= 7.06±2.31). In conclusion, royal jelly improved some kinetic parameters of spermatozoa after freezing, while it only improved BCF after vitrification. Additionally, RJ had no effect on in vitro fertility.