Effect of royal jelly as supplementation in feed and extender on sperm quality of rabbits

Background: Royal jelly (RJ) was applied as a supplement to boost rabbit production in Malaysia while examining its impact on buck fertility. Aims and objectives: To evaluate the effect of RJ on sperm quality by oral administration and extender and to investigate the effect of RJ on the histology of rabbit’s testis. Material and Methods: Twenty male rabbits were divided into four groups, each consisting of five bucks. Bucks in the Control (C), T1, T2, and T3 groups were supplemented with 0mg, 100 mg, 200 mg, and 300 mg of RJ/kg body weight three times a week, respectively, for 8-weeks of period. A sperm evaluation was performed once every two weeks. The sample was pooled and divided into two extenders: a control extender (TCFY) and an RJ extender (TCFY with 10mg of RJ). Sperm characteristics, sperm viability, sperm motility, sperm progressive motility, sperm abnormality, and seminiferous tubule diameter were evaluated using a compound microscope. Results: Bucks in T1 showed significantly higher (p<0.05) sperm viability, sperm motility, and sperm progressiveness compared with T2 and T3 in both the control and RJ extender. However, there was no significant difference (p>0.05) in abnormal sperm between all groups. Next, RJ extenders showed a significant difference in viability sperm than control extenders (58.10±1.37 and 46.52±1.79, respectively). Furthermore, there was no significant difference (p>0.05) in testis weight between groups, but seminiferous tubule diameter showed a significantly positive (p<0.05) in T1 compared to control groups (246.03±1.92 and 194.72±1.66, respectively). A high concentration of RJ has a negative effect on sperm quality. This may be due to the high concentration of RJ. Its components may result in an imbalance in redox reactions due to their excessive antioxidative activity. Conclusion: This concluded that RJ proves to improve sperm viability and sperm motility, but the dose of RJ was very important because it has several effects on sperm quality.