The present work was designed to study the effect of propolis (P) with or without royal jelly (RJ) and bee honey (H) on age of sexual puberty, semen quality and fertility of New Zealand White (NZW) rabbit males. Sixty pre-pubertal NZW rabbit males were used in the present study and were randomly divided into 3 groups (20 bucks per group); males were administered orally with 0.5 mL of a solution/ kg body weight (BW), 3 times weekly for 6 weeks. The solution contained: 1) water for control (1st group), 2) 15 mg propolis with 200 mg royal jelly (RJ) suspended in 0.25 mL bee honey (H) + 0.25 mL water (2nd group), 3) 15 mg propolis (P) was suspended in 0.5 mL water (3rd group). Fertility of rabbit bucks was tested using artificial insemination of 60 hybrid nonparous rabbit females (20 females per each experimental group).
Male NZW rabbits received propolis with or without royal jelly and bee honey showed significant (P<0.05) earlier age at puberty (earlier ages at testis descending into scrotum, separation of penis from sheath, fighting, first ejaculation, appearance of sperm in testis and epididymis). The results also revealed significant (P<0.05) increase of ejaculate volume, percentage of sperm progressive motility, sperm-cell concentration and seminal plasma fructose concentration in treated groups compared to control group. On the other hand, reaction time, percentages of dead and abnormal spermatozoa increased significantly (P<0.05) for control group compared to the other two groups. Blood plasma concentration of testosterone increased significantly (P<0.05) for both 2nd and 3rd groups in comparison with control. Otherwise, plasma concentrations of cholesterol, aspartate amino transferase (AST) and alanine amino transferase (ALT) were reduced significantly (P<0.05) for 2nd and 3rd groups compared to control group. Rabbit bucks treated with either propolis with or without royal jelly and bee honey showed better fertility (higher conception rate and litter size) than control bucks.
In conclusion, the results of the present study showed that oral administration of NZW rabbit males with propolis only or with royal jelly and bee honey could be used beneficially to have earlier age of puberty, improve semen quality and fertility. This improvement was also mirrored on better liver functions.