Jimmy Boyd

A racing horse gives birth to two colts, one of which has a split hoof and is about to be destroyed. A young stable boy saves the horse and raises it to be a champion racer. One day the boy enters his horse in a big race and finds out that the favored horse in the race is his colt's now-grown brother.

The misadventures of a single adoptive father raising a teenage niece with the help of his manservant. (imdb)