Depends on the animals.

My cows are fed exclusively grass, right to finishing.

My pigs and chickens are fed mixes of locally-sourced corn, oats, barley, peas, and lentils from organic growers. And they supplement with grasses and broadleafs because we raise 'em on pasture.

Well-raised, environmentally reasonably-fed animals cost lots of money.

Meat is basically the healthiest thing people can eat.

If you just take the pasture-raised cows alone, the grass grows itself and large herbivores are a natural part of the environment here--the environment and its polyculture would be harmed by their removal.