PID temperature controller in pig nursery: improvements in performance, thermal comfort, and electricity use.

The use of smarter temperature control technologies in heating systems can optimize the use of electric power and performance of piglets. Two control technologies of a resistive heating system were assessed in a pig nursery: a PID (proportional, integral, and derivative) controller and a thermostat. The systems were evaluated regarding thermal environment, piglet performance, and use of electric power for 99 days. The heating system with PID controller improved the thermal environment conditions and was significantly (P < 0.001) more efficient in terms of electricity use to produce 1 kg of body weight (2.88 kWh kg(-1)), specific cost (0.75 R$ kg(-1)), weight gain (7.3 kg), daily weight gain (0.21 kg day(-1)), and feed conversion (1.71) than the system with thermostat (3.98 kWh kg(-1); 1.03 R$ kg(-1); 5.2 kg; 0.15 kg day(-1), and 2.62, respectively). The results indicate that the PID-controlled heating system is more efficient in electricity use and provides better conditions for thermal comfort and animal performance than heating with thermostat.