I don't know what battery cages are, and I assume that you are wanting to know about veal cages for veal calves, which I have never been around either, but I do have an opinion about sow crates. Unless someone has been around a lot of hogs in various environments, they cannot make an educated statement as to what is best or most comfortable for the livestock. I have worked with hogs in a total outdoor environment, open pen confinements, both for gestation and finishing, and crated gestating sows. The crated gestating sows are better off in the crates B/C there is always going to be a pecking order with these animals and IMHO it is more cruel to see the lower end getting beat up and thin while the ring leaders are fat & mean to the smaller, weaker sows. In the crates you can easily adjust the feed amount to put weight on the thinner animals. As far as farrowing crates verses open pen farrowing, the amount of less crushed pigs alone would atest to the farrowing crates being safer & better than the open pens. If you were to walk into a well run farrowing room you could see immediately how comfortable the sows actually are. My farrowing house when I had hogs was actually more comfortable than my house.