Thank you, Chelle, Stone, and Porkpal,
I found your information very useful. A friend of ours raises rabbits so my DH took the manure spreader over to his place to have him fill it with the rabbit poop and then my DH will bring it here and put it in a pile. We have 5 horses and a mule so I will try some horse manure in some beds and rabbit manure in other beds and compare the two. I may also use some good aged cow manure on a couple beds and compare the three. Of coarse, they will all probably have different plants in them so am not sure if I will get a try comparison.
Thanks for your help.