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. Heifer is the female cow who has passed the calf stage but has not reached the cow stage. Usually, the calf stage ends when the age reaches 10 months from birth. A female will be called a cow when she becomes a mother after reaching the reproductive viability. The heifer is the middle stage of the calf and cow.