[Cannoneer No. 4]

At the command PREPARE TO DISMOUNT TO FIGHT ON FOOT, every fourth trooper becomes a horse holder. When the other troopers grab their rifles and dismount they hand the reins of their mounts to the horseholder as he rides by. The dismounted troopers form a skirmish line while the horse holders go to the rear. The horse holder has to control his own mount and three others while the dismounted action takes place.

[MindBender26]

YES.

Knew an old retired E-7 at Ft. Sill who had been a horse holder. Job was usually given to green kids or old semi-disabled privates. Those were days when men served 30 years and retured as Coroprals and Captains.