The present invention provides antibodies which specifically bind early
conception factor, which can be found in body fluids of animals including
but not limited to the cow, cat, dog, horse, human, sheep, and pig. The
invention provides methods for detecting conception or the absence of
conception in an animal, the latter being recognized by the absence of
early conception factor in a suitable body fluid collected from the
animal. Apparati for detecting early conception factor in a body fluid
from an animal comprising the antibodies which specifically bind early
conception factor are also provided.