dr. nancy martin, who is an experienced vet and is giving them hands-on training working with bulls on ao county family ranch. >> it's really amazing, because you can only learn so much in a classroo. the classroom gives us a great basis, and then coming out during the summer, it just gives us the clinical experience that helps tie all the ideas we get from the classroom together. >> today they're learning to test the bulls for disease. it sounds simple, but it's not, especially as some of these bulls can weigh 1,300 pounds. >> yeah. no, the first time that i had to measure the... you know, something under the bull, and every time he moved, i jerked back, pulled away, because i don't want to get kicked. but i think that having that awareness and that respect for the animal is what prevents me from getting hurt. >> ok, zuhal. 89-79. >> despite their busy day, there's always time for fun. and it's usually muddy fun. this testing program is important for cattle ranchers like kim and hry favier. they're fourth-generation ranchers who own the bulls on this family ranch. >> it means a lot to u