My cats keep away the mice, rats and wild birds. They have never touched a chicken and I trust them around day old chicks. On my farm they are more then welcome.
Thank goodness my big birds really are big, but I have lost WAY to many chicks to cats who have gotten into brooders. They are my #1 preditors here. They have attacked the bigger birds and I've treated scrathes, but I've been able to hear the chickens scream during attacks and chase the cats off. I used to love cats, but just this close to completely hating them now. And yes my brooders were closed and solid. I have yet to figure out how they've done it.
Oh- I did not think I needed None of the Above becuase when I voted - I had a null vote option.
I just caught my best hunter, a female raised in the wild for the first 4 months of life, in pounce position. When my mallard walked by, she went for a hiney swat. I chatised her. I think it was a play action of opportunity. My cats and dogs play and tussel pretty roughly sometimes.