I think the biggest problems I see if everyone went veg would be medical products that are made of slaughterhouse by products and family farms such as ranches losing their livey hoods. I can see how people who live on ranches and possibly don't know any other way of living would feel very threatened.
Surplus animals would not be a problem among domesticated animals. Wild animals people hunt is a different story.
Surplus animals would not be a problem among domesticated animals. Wild animals people hunt is a different story.