The company's name is Igenity.  You will need a blood, hair or tissue sample of the bulls and calves in question.  Once you have the parentage test done on the bulls you won't have to do it for successive years.  The hair and blood cards were free, but I don't know if they still are as it has been a few years since I got the ones I have used.  I usually use the tissue samples because it is a little easier and cleaner, but you have to buy the tissue sample equipment.