Make sure it is not broken. If it is, they are very easy to splint, and will heal rather quickly.
I have had this happen a couple of times. Calves get stepped on when they are young and break a leg.
To splint, take a piece of 3" PVC pipe and cut it into thirds, about 30" long. Find some foam, old rags, or something along thos lines that you can line the PVC pipe with and prevent it from rubbing on the calf's leg. Next, and this may take some assistance, lay the calf down and put the PCV pipe on the back side of the calf's leg with the rags or foam inbetween the leg and the pipe. Leave the pipe BELOW the hoof about 2 inches so they walk on it rather than the hoof. Finally, be sure the calf's leg is straight and take some good old fashioned duct tape and tape it on. Be sure to watch for pressure points, so the pipe does not rub on the calf's hide. That could lead to open wounds, which will lead to infection. Leave the splint on for 4 weeks, and it will be good as new.
Had to do this last year. The calfs leg was slightly crooked, but to the casual observer you would never know.