Keeping your stock cool and comfortable this season is vital to their growth and performance. They need to be able to get out of the direct sunlight and have adequate, clean, fresh water at all times. And no, a stock tank is not acceptable for pigs. Remember if your pig doesn't drink, they don't eat either. You may consider a fan or some way to move the air in their environment. Also if you are concerned about your projects intake do to the heat you may want to supplement a low dose of electrolytes. This will help your project stay hydrated. Good luck and beat the heat!