Has anybody got some experience finishing bulls?

I currently finish steers and heifers on bales silage and concentrates. I have in the past finished black and white bulls where they came on the farm at 6 months old and were finished at 13 months old. I liked the quick turnaround and how fast they grew although they were on a adlib concentrate and straw only diet.

I have been told that processors require bulls to be finished by 16 months or younger. Is it possible to finish them at that age feeding them silage with concentrates or does it have to be a concentrate/straw only diet. I am not looking at doing black and whites again but say angus cross or continental cross bulls.

Anybody with experience fattening and finishing bulls who could give me some advice on diet and what ages/weights they manage to finish them at I would appreciate it.

Thanking you in advance