if we were to stop killing , pigs cows, sheeps and other anim als we eat then they would be overpopulated and lets say cows eat grass if there was overpopulated cows they would eat all the grass and all th eother aniamls that eat grass will die due to the lack of food and the animals that eat the animals that die they would soon die because there prey would be dead so we can basicly ruin the food chain in so many ways let me know if this helped you :)
