Pretty much anything can stop alpha radiation. Beta radiation needs a bit more, but again it doesn't take much. So hypothetically, a typical cow patty could block some forms of nuclear radiation.

Gamma radiation, depending on the energy can penetrate lead and concrete. So unless you're talking about multiple cubic meter sized cow patties they aren't going to be blocking gamma radiation.

However, based on what this miserable idiot of judge has said I doubt he has any idea what he's actually talking about.