I have noted that the best way forward would be to create stricter eutrophication laws and tax artificial fertilizers produced from fossil fuels. This would feel very contradicting to vegetarians and vegans, but factory farming would be hit comparable much harder and it would directly address the environmental factors of factory farming without harming biodiversity.

A complicating factor in this discussion is that a large portion of the feed to cattle comes as a by-product from ethanol production in things like bio fuel. The process result in about 1/3 of the original crop becoming fuel, 1/3 becomes feed, and the rest is waste/water. With more and more focus on producing bio fuel, a natural result is the creation of more feed as a by-product.