I have not read this paper—I will put it on my reading list—but for folks interested in the subject, I recommend Norwood and Lusks’s book Compassion, by the Pound: The Economics of Farm Animal Welfare, specifically chapter 5, which covers different rearing systems. They argue, and I agree, that cage-free systems are better overall for chicken welfare but note that many farmers and specialists feel that caged systems are actually better for overall flock health. For instance, mortality is higher in cage-free systems due to diseases, pecking etc. (Here is some contrary evidence.)
I have not read this paper—I will put it on my reading list—but for folks interested in the subject, I recommend Norwood and Lusks’s book Compassion, by the Pound: The Economics of Farm Animal Welfare, specifically chapter 5, which covers different rearing systems. They argue, and I agree, that cage-free systems are better overall for chicken welfare but note that many farmers and specialists feel that caged systems are actually better for overall flock health. For instance, mortality is higher in cage-free systems due to diseases, pecking etc. (Here is some contrary evidence.)