When did they have the still born calves? (stage of pregnancy?) Did they udder up? If there is little/no indication of them calving, here they would go in a pen where there are similar open heifers and they will bring considerably more than a straight cull cow. Sold 2 this past spring that came up open for the 2nd time, one out of a cow that was a problem breeder, the other had been checked preg and slipped it, and they brought about twice the cull cow price. They were in very good flesh but not globby fat. No udders to speak of.
I would worry about still born calves if they were full term or close to it. Only had problems with some dead calves, it was the winter of all the cold rain/snow and freezing temps; some were probably born alive and we just didn't find them soon enough and they got chilled and died before they could get up and suck. Lost 4 I think. But to just have a few stillborns would worry me like others have said.
Why not just do freezer beef now?