Hard to tell his size real well from the picture, but I think he should do ok for light service as long as there's not a huge size difference between him and your cows. Physically he could find a way to make it happen, but like you say you don't want him to get hurt trying either. I would make sure to keep feeding him along since he has a lot of growing to do and working will take some out of him. I bought my current bull about that same age/size, and he has done fine. He only had 3 or 4 cows for his first few months though.