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..
Heifer: A heifer is a female animal that has never had a calf. Once a heifer has a calf, she automatically becomes a cow. Bull: A mature male animal that is used for breeding. (And for the record, I did know what a bull was when I initially asked my city kid question!) Steer: A steer is a male animal that has been neutered.