I don't know of a website that has information on the subject, but I have been around holstein steers for most of my life, and from my experience, as soon as possible, get them on grain and pump the grain to them. This way they will finish quicker and also IBP/Tyson pays well on holstein steers if their below a certain live weight (1,475 pounds ?). Anyway, make sure they have enough roughage in their ration or otherwise they are apt to bloat.