The correct spelling is "cramp" and not "calf". The cramp is the involuntary contraction of the muscle and is usually very painful.
voluntary
No, the calf muscle is skeletal muscle. Smooth muscle is found in organs like the stomach and intestines that are involved in involuntary movements, whereas skeletal muscles like the calf muscle are attached to bones and are responsible for voluntary movement.
They are involuntary muscles.
Calf. The same terms that apply to cattle generally apply to bison.
A calf a full grown calf is a cow!
A stray calf is commonly referred to as a "lost calf" or a "wandered calf."
Calf's. The calf's tail was swatting at the fly.
A baby buffalo is called a calf.
The offspring of a cow is referred to as a calf. A heifer calf is a female calf, a bull calf is an intact male calf, and a steer calf is a castrated male calf (castrated after birth).
Both. A calf is a general term for a young bovine, regardless of sex. A calf, thus, can be either male or female. A male calf is called a bull calf, and a female calf a heifer calf. If the bull calf has been castrated, he is then called a steer calf.
A nonspecific calf injury. If your calf is knackered then you have calf-knack. It is a colloquialism from Britain.
A newborn calf, a baby calf or just a calf.