The pressure in the pleural cavity of livestock is generally equal to atmospheric pressure.

The pressure in the pleural cavity of livestock is less than atmospheric pressure. According to relevant data, the pressure in the pleural cavity of livestock is negative pressure when it is less than atmospheric pressure, and the pressure in the pleural cavity at the end of quiet exhalation is negative pressure. When breathing quietly, the intrapleural pressure is always negative pressure. When the glottis are closed, the intrapleural pressure can be reduced to a very low level. Intrapleural pressure refers to the pressure in pleural cavity. It is determined that the intrapleural pressure is lower than atmospheric pressure, and it is negative pressure when inhaling or exhaling.