I don't know. Make some warm mash. heat the milk and food and make pooridge for 'em is there much chickens wont eat? I just gave mine the last of the garden tomatoes, they were getting soft
If it's actually spoiled it's not a good idea to give it to them. If it's just "old" and not rotten, then it should be fine.
I've heard milk was not good for them. However, some folk mix in buttermilk with active pro-biotic cultures with feed and some have used calf-mana.
