Here's an investigation that vegnews.com has just added to their website. I haven't read it, because I know this would be agonizing. But, if you are still on the edge about the cruelty of factory farming, please do read it. This is something everyone needs to feel agony over (since only this will change these practices).
Warning: you may feel a certain mental discomfort; this is your conscience. Welcome it. It is here to make the world a better place for us all. Humans and animals alike.