Here's the general process I do. Go to the ASA database, type in the sire and then dam of the bull in question, and look at the actual birth weights of the progeny.
I saw Cabrera in Denver- in fact I led him from the tie outs up to the barn. By visual appraisal alone, the bull looks like a heifer bull candidate. He's moderate framed, square on his feet, and pretty smooth made throughout. Primo has some big bw's, but I guess time will tell whether Cabrera inherited that trait or not. He's a good bull, and once Matt will sell me a few straws, I'll use him.
I've seen a picture, there are calves on the ground.