Farmers describe how GMO feed makes their animals sick:
Many things were tried, but the one common thread among the farmers on the film was that they all ditched GMO feed for a non-GMO blend. The improvements were significant and they were noticed in a short period of time. The cows and pigs continued to improve more and more as time went on.Danish farmer switches to non-GMO feed, health of pigs improve dramatically.
Iowa farmer switches to non-GMO feed, drug costs for animals cut in half. Jim Blomgren switches to non-GMO seed, which is cheaper.
Long-term toxicology study on pigs fed GMO feed. PDF. ISSN 1177-4258. Journal of Organic Systems, 2013. Flawed study claims GMO feed is safe. Discussion here.
Scratch and Peck.