A lot depends on what type of longhorns you are dealing with. But, in general, Longhorns are good mommas and have good calving ease, they lack in the muscle and growth department. I would go with something bigger framed, with lots of muscle and growth, and solid colored. My friend has lots of success with charolais cross. Calves grow good and most come out tan or cream. I think they have a Maine/Simm cross bull now, and the calves are just hitting the ground this spring, but have been growing fast once they hit the ground.
Ryan