Ok. Solve it without making the problem worse.

Remember you can't grow crops on the land we run most cattle on, it's marginal or steep.

If we remove cows from the marginal land, and sheep from the steep land deer and goats move in

Deer and goats are ruminants like sheep and cows. They will have the same emissions

Presumably we won't be farming the land, it'll be national parks or similar

So with cows and sheep we have a chance of improving their emissions, because we can inoculate them with specific methane eating bacteria, we can feed them supplements that let the existing bacteria crack methane.

With wild animals it's hard to do anything.