In my own opinion…
I will not offer a bottle baby bull calf to anyone, unless they are being castrated and becoming a steer. Bottle baby calves are fun to be around and the joy of feeding them can be really neat and fun, however, you have to remember though that when you are bottle feeding, you have now became the mammary gland of a cow. You have in essence became their mama. Just like your own child, everything you do, you imprint it on the calf.
The key is to have them understand you are the Alpha in the herd AT ALL TIMES. When bulls become older, they go through a “rebellion” stage around 18 months to around 3 years old. We call it the “terrible 2’s”. We compare them to a teen ager and/or baby. They have a habit of not listening. This is the most important time to teach the respect that you want.
The number one rule… Do not let them head butt you or push on you with their head.
The number two rule… Do not push back. It only encourages the behavior. That’s what cows do. They push and head butt.
This goes for both males and females. This is how they fight and play with the rest of the herd. It’s how they establish dominance and their own pecking order. We have babies that will try to push on us at 2 months old. It may be cute, but when they are 5 years old, it can become dangerous.
We use the word “No” a lot when we are training and we pop the nose with our hand when we have behavior like pushing and head butting. It’s just behavior that we don’t tolerate to humans. I have to believe it has kept us safe over the years.
In the end, I look at what they are doing when they are a baby and then try to imagine what the same behavior would be like when they are 4 or 5 years old when they are 400 or 500 pounds.
I always remember that a bull is still a bull. Even though they are smaller, they are still a bull. When they are older, we always keep one eye on the bull at all times when we are out in the herd doing things.
I would start them on a lead and halter as young as you can. They are easier at that age simply because they are small and don’t weigh a whole lot. Plus at a young age, you imprint the behavior easier and quicker with them than when they are older or adult age.