"A ban on packer ownership of livestock and other alternative marketing arrangements (AMAs) in the beef industry would cost producers, packers and consumers billions of dollars."

Since wealth is not created nor destroyed, merely transferred, there has to be somebody gaining those billions of dollars.  Not everybody can lose money.  If the packer's costs go up, that is probably because they paid more for the cattle or because the retailer paid them less for the beef.  In that case the packer's loss is offset by the producer's and retailer's gain.  If something cost the producer more, the packer or feeder would be in line for the gain.  Claiming everybody loses money makes no sense.