An exposure pathway-describes a unique mechanism by which an. individual or population is exposed to chemical or physical agents at or originating from. a site. Each exposure pathway includes a source or release from a source, an exposure. point, and an exposure route.
Terminology: Young cattle are called calves. A young male is called a bull calf; a young female before she has calved the second time is called a heifer (pronounced heffer). A young female that has had only one calf is sometimes called a first-calf heifer..
These cows that can't produce milk are known as (called something like this) free-martyrs, this only normally happens when a cow, known as a heifer (name of a female cow that has not given her first calf or milk) is a twin with a bull calf (a male cow). Im not sure how this happens but it is to do with featal development.