I was told by someone who knows recently that pollarding russian olive works great. Here, pollarded willows are the most common tree (pollarding means coppicing up high, out of the reach of browsing animals). We've got a couple of russian olives that have gotten big, and a
local farmer told me that it's fine to cut them off like willows in late winter. They'll make loads of straight shoots just like willow, but much harder, he said. I've seen elsewhere on this site, I think, that "Russian olive eats saw blades for lunch."
But I don't know if cattle will eat it for fodder. Around here, willows and poplars get badly stripped and eaten if not protected, but Russian olive doesn't seem to get browsed much.