I would castrate them since they are probably occasionally nursing. They'll recover quicker feeding on milk.
You'll get a notably lower price for bull calves vs steers.
Feedlots and stockers don't want bull calves. So they have labor cost , initial weight loss, and risk castrating big calves. You get docked for this.
There is a strategy to let calves develop as bull calves to build frames and muscle then castrate them as larger calves before fully weaned.
I did this strategy for a couple of years with good results using a Callicrate surgical tubing bander.
Also if you have really good winter pasture ( oats & ryegrass) , consider holding all your April calves and selling in Spring. Market is always much higher in Spring than in Fall. It's worth holding bulls back to shift calving season to May/ June to do this.
The bander is for sale if interested. With several bands and case.
$300 shipped.
https://callicratebanders.com/industry-tested/?gad_source=1&gad_campaignid=1000982063&gbraid=0AAAAADKnzkKrBPfSFxnXsnp3KgH4tvvvb&gclid=Cj0KCQjww4TGBhCKARIsAFLXndTwiia50PRuT17-XV0wGoDMrEiuzET0QMp-keYH44hJLjN-4qjqazAaAtU0EALw_wcB