Rojal jelly supplementation can improve boar semen motility and viability parameters during liquid storage

Abstract

Royal jelly is gluten secreted by hypopharingeal and submandibular glands of young worker bees and has different types of biological activity in various cells and tissues of animal models, and serves as an antioxidant source (1, 2, 3). A successful effect of royal jelly supplementation on sperm quality and fertilizing ability has been reported in domestic animals (4, 5, 6). The current study was carried out to investigate the protective effects of the royal jelly supplementation on the sperm kinematics and plasma membrane functionality during the liquid storage of boar semen at16°C and 4°C, at various periods of time (0, 24, 48, 72 and 96 h). Semen samples were collected from 11 boars, diluted with a long-term extender and supplemented with different concentration of raw royal jelly (control – 0%, 0.5%, 1% and 2%) at a final concentration of 50 × 106 sperm/mL. Only those samples having more than 75% motility and more than 75% normal sperm were used for further experiments. In the laboratory, the semen was assessed for sperm morphology, viability (eosin-nigrosin staining),subjective motility and objective sperm motility by the sperm class analyzer (SCA). Sperm viability and motility in two ways were checked after 24, 48, 72 and 96 h of incubation. In total, 396 tests for sperm viability and motility were performed. The longer storage time and the lower incubation temperature showed the lower sperm motility and viability results in the all treated and non-treated samples. The results showed that royal jelly supplementation at lower concentration (0.5% and 1%) for storage time at 16°C temperature resulted in aprotective effect on cell membrane integrity; however, the liquid storage of semen supplemented with 2% royal jelly had a negative effect on sperm plasma membrane integrity. The highest viability values were found in 1%royal jelly concentration at all storage times at 16°C temperature. Sperm subjective and objective motility SCA results in the samples stored at 4°C decreased with a higher royal jelly concentration and a longer storage time and differed significantly compared with results in the samples stored at 16°C (P < 0.05). Our data showed that the royal jelly supplementation at lower concentrations can improve boar semen motility and viability parameters during liquid storage at 16°C for 96 h and no protective effect was observed for sperm functionality and kinematics at 4°C temperature.