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Abstract. Lactating sows in farrowing crates are susceptible to thermal stress, particularly in hot summer months, resulting in decreased feed intake, increased respiration rate, and reduced milk production. This ultimately reduces piglet weights at weaning. A thermally conductive cooling pad has been developed to remove excess heat from lactating sows through direct contact, rejecting heat into a liquid coolant. An electronic control system was recently added that utilized either a temporal or temperature threshold-based control scheme to intermittently flush cool water through the pad, replacing water that had been warmed by the sow. Twelve lactating sows were provided cooling pads to test the effectiveness of each control type and study how the variation of each control‘s main parameter affected the heat transfer from the sows. The main parameter for the temporal control was the time between flushes while the main parameter for the temperature threshold control was the threshold temperature. All sows were exposed to each main parameter variation for each control type in a random order using a Latin square design to negate any serial effects of treatments. The ambient temperature inside the barn was maintained at 32°C for the duration of the experiment. The effectiveness of each control-parameter combination was measured in kJ of heat removed per liter of water. This data will allow further refinement of the electronic control system, reducing the water necessary to achieve a certain level of heat removal from the sow and optimizing the control protocols for specific animal and environmental conditions.