How old is a cow killed to produce meat?

Beef, just like any other meat from other bovines. However, if the beef is not good quality to be made into steaks, it will be made into ground beef for hamburger, meat balls, stroganoff, etc.

Yes.

A cow is never too old to be slaughtered and processed for meat for human consumption. However, the older a cow gets, the tougher the meat becomes and the less desireable it is - most cows over the...

She has to have a calf before she produces milk, so most cows are at least 24 months of age before they start producing milk.

Between 2-3 months of age.