Support more local organic farmers and a drastic decrease in population. The first one is obviously the only viable solution, but the latter is what I wish for. Epic feed lots are simply not sustainable and are terrible for the environment. Both are problems we need to quickly address or face the complications of balance attempting to be restored. We can't exist in disequilibrium and there is nothing smart or balanced about the way we are currently managing the huge feed lots that girdle across our country. If I need to explain why its gross that hormone pumped steers are forced to live in pens littered in their own shit, fed poor quality feed and injected with antibiotics to help cope with the awful conditions isn't a smart or efficient practice then...... monoculture woo! Thats for a different discussion, though.
Perhaps turn more suburban and open city areas into small farms so people can slowly take control of their own food and grow it themselves. You're right, grass fed beef isn't capable of supporting our massive nurabers....so if our practices don't change the problem then perhaps we need to change our population. I know we're on our way to that anyway. Its Bio 101: Any organism that becomes over abundant, and lacks an apex predator will wallow in its own waste, use up resources, experience genetic instability, and then see a drastic decrease in population size. Equilibrium.
They actually DO round up wild horses for slaughter. They also auction them off but guess who also has a presence at horse auctions.... They round up wild horses to "keep populations small" so they don't encroach on farmer land. I believe its an annual thing. Thats how you get the "Adopt a Mustang" thing.