I have an older cow that calved a week ago. She has a very large and full looking udder. The problem is she doesn't seem to be letting the milk down. I have nursed her by hand and the calf nurses like crazy but only gets little squirts of milk if anything at all. Also her teats tend to seal over about every day. I started putting dilators in her overnight to see if this helps but I don't think it's the answer. Any suggestions? Thanks.