Flight of the Swan
Herds of Thunder, Manes of Gold: A Collection of Horse Stories and Poems.
After Don Andreas Sepulveda bets that his mare, Black Swan, can win a race against Governor Don Pio Pico's stallion, he announces that his young son Antonio will be his rider. Antonio's special bond with Black Swan and his light weight give him just the advantage needed to win the race and along with it five thousand pesos and one thousand head of cattle. An oft repeated theme exceptionally well told.