Abstract
Royal jelly (RJ) is one of the furthermost valuable curative products mentioned by natural medicine scientists due to its promising medical and nutritional purposes. It possesses many impacts, including antioxidants, antimicrobial, antitumor, anti-inflammatory and immunomodulatory functions in human and animal that benefit their health and welfare, resulting in its widespread use in medical and commercial products and healthy food. Recently, favourable functions of RJ on male fertility have been reported in different animals. According to earlier literatures, the level of RJ supplementation in animal diet ranged from 100 to 200 mg/kg. Oral exposure to RJ has been reported to have oestrogenic influences in the adult female rats. Also, RJ may be influential in improvement of pregnancy and lambing rates of ewes. Oral administration of RJ at 100 mg/kg diet before sexual maturity enhanced sexual behaviour and semen quality of male rabbits. Moreover, RJ administration (up to 400 mg/kg diet once weekly) for male rabbits exposed to heat stress can counteract "summer infertility" and improve physiological responses. Furthermore, supplementation of freezing extender media with 0.1 or 3% RJ had a protective influence on cryopreserved and chilled spermatozoa of buffalo and ram respectively. However, the high dose of RJ oral administration (800 mg/kg) by pubescent male rats for 1 month had an undesirable effect on the reproductive system; however, the somewhat unfavourable influences were mitigated by the discontinuation of the administration. This review shows the chemical composition, favourable applications and health benefits of RJ and its effects on reproductive aspects, semen quality and in vitro fertilization outcomes which are advantageous for scientists, researchers, nutritionists, physiologists, embryologists, pharmacists, veterinarians, pharmaceutical industries and animal's breeders.