Determination of pregnancy status in ungulate ruminants

A method for determining pregnancy status in an ungulate ruminant animal comprising determining the level of extra-uterine expression of a pregnancy-induced protein in blood or milk collected from the animal during the period 15 to 30 days following breeding, wherein the protein is an Interferon-tau induced protein, and comparing the level of expression of said protein in the animal to that of a non-pregnant female animal of the same species, wherein an absence of increase in the level of the expression of the protein in the animal compared to that of the non-pregnant animal indicates that the animal is not pregnant or where an increase of two times or more in the level of the expression of the protein in the animal compared to that of the non-pregnant animal indicates that the animal is pregnant.