Once you have purchased a second stable on your ranch, you can transfer some of your horses over to the second stable to help organize. To move your horses, go to your stable on the left side of the game, and then click on “Your stable” on the top tab. From there, you can click on “transfer horses”. Select which horses you want to move.
Note: Horses in your second stable will count towards your total horse number, but when you “view horses” from your homepage, the horses in your second stable will not appear. To view the horses in your second stable, you must to go your stable page, then instead of clicking on “transfer horses”, click “second stable”.