Optimizing Swine Reproductive Performance: Insights from Hourly Flushing Rates and Temperature Trends of Electronically Controlled Grouped Floor Cooling Pads


As swine producers strive to enhance reproductive performance, mitigating the impact of summer heat stress on boar semen quality is of paramount importance. A recent study conducted by researchers from Purdue University, Innovative Heating Technology, and Pig Improvement Company Inc. sheds light on the management trends of electronically controlled grouped floor cooling pads (ECP) in a boar stud during the summer heat stress. The findings offer valuable guidance for producers seeking effective cooling strategies to maintain optimal reproductive conditions.

Objective and Methodology:

The study aimed to assess the flushing management trends of ECP during summer heat stress in a boar stud located in Scottsville, Kentucky. Four groups of five ECPs connected to each other were strategically placed in 15 boar crates within a 350-head evaporative cooled, tunnel-ventilated barn. Temperature sensors were strategically positioned on the 5th pad (Zone 1) or the first pad (Zones 2 and 5), triggering the flushing of 4.25 L cold water when specific temperature thresholds were reached. The researchers collected data on hourly ECP temperatures (PT), ECP flushing rates (FR), barn temperature (BT), barn relative humidity (RH), barn dewpoint (DP), and cooling tank temperature (TT) to analyze the efficiency of the cooling system.

Results and Discussion:

The study revealed that flushing rates (FR) and ECP temperatures (PT) were influenced by the zone, hour of the day, and their interactions. All zones exhibited higher flushing rates (Mean: 64.6%) during late morning to afternoon hours (1100 to 1600), gradually decreasing in the evening (1900h onwards). Zone 1 demonstrated the highest flushing frequency (47.7%), followed by Zone 2 (39.9%) and Zone 5 (33%). Interestingly, Zone 1 ECP temperatures averaged 26.7°C, Zone 2 at 22.1°C, and Zone 5 at 20.7°C, maintaining optimal conditions for boars.

Moreover, Zone 1 flushed less frequently (30.3%) during the nighttime (2100h-0400h), resulting in a cooler ECP temperature (Mean=26.7°C) compared to midday (27.1°C). The study found that the set temperature (27°C or 24°C) or set time every 4 mins effectively maintained ECP temperatures below the specified thresholds, ensuring optimal cooling conditions.


The meticulous evaluation of ECP flushing management trends during summer heat stress provides swine producers with valuable insights for optimizing reproductive performance. The study highlights the importance of understanding hourly flushing rates and temperature trends to effectively manage grouped floor cooling pads. Implementing such strategies can contribute to maintaining desirable ECP temperatures, ensuring boars experience minimal heat stress and ultimately preserving semen quality. Producers are encouraged to consider these findings in the design and management of boar studs, further contributing to the overall success of swine reproductive programs.