Well, it definetely sounds funny and very likely is an urban myth, but royal jelly, when fed to a chicken might result in a doubled egg production.I saw this fact on many royal jelly e-stores, and these retailers usually cite Cornell University in Ithaca. I’m not sure if this has been well researched.
Some more research info about royal jelly and chickens

• Bonomi, 1959. Observations and remarks on the effect of royal jelly on the increase in weight, the haematological picture, the development of male gonads and the demobromatological composition of the flesh of chickens
• Giordani, 1961. Effect of royal jelly on chickens.

AND:

Wikipedia article on RJ has been moderated. They have removed this website. THey obviously cannot believe someone can have a royal jelly website not beeing a spammer.  Well … The  users will tell, won’t they.