I have a 2 and a half week heifer, she is a holstein, Jersey mix. She is a small one. She has been chewing on the cattle panels, to the point that it makes your ears hurt. She chews on them all the time. Is she lacking a mineral? She doesn't seem to have any other issues. I have been offering her sweet feed, but she doesn't seem interested in it at all. How can I get her to quit this?