A Two-House Field Comparison of Multi-Parameter and Conventional Environmental Control for Rabbits Under Hot–Humid Summer Conditions

This study compared a programmable logic controller (PLC) combining indoor temperature, outdoor temperature, and outdoor relative humidity with conventional temperature-triggered pad cooling and manual fan adjustment in two commercial rabbit houses in Leshan, China, a region characterized by a hot and humid climate. The 33-day summer trial included 108 selected Hyla rabbits aged 39 d per house. The PLC house had a mean air temperature 0.36 °C higher and relative humidity 4.34 percentage points lower than the control house. Final body weight and average daily gain were higher, while feed conversion did not differ significantly. Intra-abdominal temperature near the cooling pads was 0.29 °C lower. Estimated cooling pad recirculation was 81.0% lower and combined fan and pump electricity use was 21.2% higher. A partial-budget analysis at a standardized scale of 3000 retained rabbit production-equivalents estimated a benefit 2955.95 Chinese yuan (CNY) higher for the treatment house than for the control house under the specified prices and scaling assumptions. Each strategy was applied in one house, so these preliminary differences cannot be separated from house effects. These observations support further evaluation in independently replicated houses, with animal responses, resource use, and deployment costs assessed together.