I personally don't think you need 2 roosters for 24 hens.
We have had 4 roosters for 120 hens and had an average of 89% hatch rate for 1 year. We set eggs every 3 weeks for a solid year.
Since you already have him, here is a copy from one of the FAQ in the Learning Center.
3. What is the best way to introduce new chickens to an already established flock?
Separate newcomers and established birds with a barrier (i.e., wire), so they can see each other but not directly interact for a period of 1-4 weeks. This will help keep fighting to a minimum. Always introduce them while SUPERVISED, so you can control any fighting.
submitted by C.C. , answered by admin , last updated Sep 30, 2007
This should help you
Jean