Found myself in a similar situation a few weeks back and I couldn't think of a way to do it safely - for him and for me, and especially how I would cope if something went wrong - so Odin still has his balls and we will either get the vet to castrate him later in the year or, if he behaves and there isn't an unwanted sperm issue

, live with it until he goes off (which will be November if all goes according to plan.)
We are in the throes of deciding what to do to replace the matriarch Jersey who died

and may well end up with someone fertile at just the wrong time.. or might decide to let Odin do the biz anyway as we are only producing eating calves for ourselves. But will that give him "bull taint", does anyone know? Is there such a thing?