Efecto de la jalea real suplementada a diluyentes de base sintética y no sintética sobre criosupervivencia de esperma bovino

Abstract

Royal jelly (RJ) is a nutrient produced by nurse bees (4 and 11 days old) and contains vitamins, proteins, enzymes, amino acids, and other minerals. There is limited information on the positive effect of royal jelly in ruminant sperm cryopreservation; its beneficial components may be enhanced in different diluents. This investigation evaluated the effect of RJ supplementation in synthetic (TCG= tris, acid, citric, glucose + 6% egg yolk) and non-synthetic (UHT= skim milk + 6% egg yolk) diluents on cryosurvival of bull spermatozoa after refrigeration, freezing and vitrification processes. In a first experiment, 9 ejaculates from 3 healthy bulls (3 ejaculates/week) were used to determine the most suitable concentration of RJ (w/v) at 0% (T0, control); 0,2% (T1); 0,4% (T2); 0,6% (T3); 0,8% (T4) and 1% (T5) supplemented with TCG and UHT extenders on the kinematics of refrigerated sperm for 96 hours. The results demonstrated that a low dose of 0,2% RJ (T1) supplemented to both extenders has a positive effect on progressive motility and velocities (curvilinear [VCL] and rectilinear [VSL]) of chilled bull sperm in the longterm. In a second experiment, 15 ejaculates from 3 bulls (3 ejaculates/week) were used to evaluate the effect of supplementation of 0,2% RJ (w/v) to freezing extenders (TCG+5% glycerol) and vitrification (TCG+100 sucrose). Four groups were formed according to the cryopreservation method (freezing [CONG] and vitrification [VIT]) and the addition or not (control) of RJ: (1) CONG-Co, (2) CONG-RJ, (3) VIT-Co, (4) VIT-RJ. The results showed that during freezing (CONG-RJ vs. CONG-Co, P<0.05), RJ increased VCL, VSL, and beat frequency (BCF), while during vitrification (VIT-RJ vs. VIT-Co, P<0,05), the RJ improved the BCF and integrity of plasma and acrosome membranes. It is concluded that the addition of 0,2% RJ to TCG and UHT extenders improved chilled bovine sperm kinematics. In addition, The RJ better protects sperm membranes during vitrification than the freezing process.