What's wrong with pigeons always open their mouths

Pigeons often open their mouths because they are too hot.In the summer, you should cool down and prevent heat. Pay attention to shading around the loft, and you can also put some insulation materials. Usually, doors and windows should be opened to maintain good ventilation.Pay attention to adjusting the feed matching daily feeding, increase protein and calcium, reduce the ratio of energy feed, and control the amount, do not have leftover.Drink more water in summer, so be sure to provide sufficient water.