I don’t know about England but there’s no pasture around here that’s sterile and infertile if there are cows pooping all over it. Maybe they’re trying too hard and are poop-scooping in behind them.
Poop is fertilizer, dummies.
I remember when I was a kid on the farm. Even months later when you turned a dried cow patty over the bugs, worms, etc were still working under it.