I have found my chickens prefer most other things to mulberry leaves, and one year they even ignored the fruit!
That year they were stuffed full of cicadas, so it hardly counts, but you get the idea.
As for growing mulberry among the the other fruit trees, be vigilant.
One of my
volunteer mulberry trees out grew and shaded out a pear tree that was years older.
I was very negligent, but still, these trees are persistent, to say the least.
As for other fodder, my girls like willow leaves a very much, and the branches could make for a good product, as artist charcoal or basketing material.
The nitrogen fixing shrubs and trees are good if only because of their leaf growth patterns.
They tend to leaf out late, drop leaves early, and because they tend to have compound leaves the shade is dappled and the leaves break down easily.
With those advantages, forage and human food are almost just bonuses, but some offer that as well.