Extending the Potential of Evaporative Cooling for Heat-Stress Relief

Water loss from the respiratory tract (kg/h, as predicted by Equations and the equations in Table 1) as a function of ambient temperature and relative humidity (□, 15%; ▵, 25%; ○, 35%; ■, 45%; ▴, 55%) when cooled air is at 65% relative humidity.

Heat loss from the respiratory tract (W/cow), as predicted from the thermal balance model, as a function of ambient temperature and relative humidity (▵, 30%; ▴, 55%; □, 65%; ■, 75%): A) for a cow standing with the full body surface exposed to 0.3 m/s air velocity; B) for a recumbent cow with two-thirds of the body surface exposed to 1.5 m/s air velocity; and C) for a recumbent cow with two-thirds of the body surface exposed to 0.3 m/s air velocity.

Distribution of mean omnidirectional air velocity at 10cm above the body surface at different angles around the body of 15 standing cows, when the mean air velocity (±SEM) at 1m above the back of the cow is 0.9±0.07 m/s.