A head of cow properly spoken is one cow. Head refers to a number, or rather a variable. to use the term head is just a matter of counting, usually critters, say like sheep , horses, goats even people. Asking for a head count is asking how many. "I saw a herd of Elk about 10 head. they were mixed in with a herd of holstein cows and 4 or 5 head of horses".
A cow's head is shaped sort of like a triangular prism, so that's probably what you would call it: a triangular prism.
A head gate (or head catch), or a squeeze chute. If you're referring to something bigger, then it would be a corral or pen.
Australian's terms for cows and cattle are pretty much the same as what North Americans and British call them: cows.
Cows. They speak English there you know....
A herd.
Twelve cows can be called a flink, a dozen head or a herd of cows.
Not necessarily. It means cattle in a collective term, not cows as in only cows with calves, or dry cows or pregnant cows or bulls or steers or heifers or whatever. When a cattleman says that he has 50 head of cattle, he means cows, bulls, steers, heifers and calves, not just the cows themselves.
calf
a herd
About 100-125 head cows and calves
Who knows; cows don't talk, so they'll never tell.
Cannibalistic. But in reality, cows don't eat other cows (they're strictly herbivores) so this question doesn't apply to them.