LOUISVILLE, Ky. – The weather forecast for Saturday was improving by the time trainer Chad Brown arrived at Churchill Downs early Friday morning. But he decided it was better to go with what was in front of him than risk chancing a different track Saturday morning, so out went the highly regarded Zandon for his final workout for the May 7 Kentucky Derby, highlighting a morning of activity here that otherwise focused on fillies in the May 6 Kentucky Oaks.