Don't the cattle get hardware disease or lead poisoning with the metal particles in the bales?
It can happen, but you'll need to put a lot of lead out there. Still, this is why I mostly shoot into a berm, onto a steel plate that is on a fence row that I killed off, or onto a steel plate just off the edge of a hay meadow.
Cattle first...shooting and hunting works around it.
https://pubmed.ncbi.nlm.nih.gov/9299921/