Lyle Defrees' father, Albert, had a big, mean-tempered Holstein bull.  Whenever anyone entered the corral he lowered his head in a threatening manner.

One day Albert brought a buck sheep home from a neighbor's place, and unloaded it into the bull's corral.  The bull resented the intruder, and lowered his head.  The buck sheep backed up, and with lightning speed and great impact, rammed the bull head to head.

The bull dropped like a rock.  And there he lay for a whole day—knocked unconscious.  Finally he got to his feet, and never again lowered his head to anything or anyone.