• • Ammonia emission from growing-finishing pig houses averaged 9.852 mg·m−3, below the national limit of 25 mg·m−3, but peaked at 38.36 mg·m−3 during high-temperature (>30 °C) episodes, underscoring the need for temperature-based ventilation control.
• • Total ammonia emission over the monitoring period was 1380.4 kg, equivalent to 0.034 kg·d−1 per pig, providing a benchmark for regional nitrogen load assessments.
• • The exhaust gas absorption device reduced ammonia concentration to 0.437 mg·m−3, achieving a recovery efficiency of 93.5%, demonstrating high technical feasibility for ammonia capture.
• • Temperature was the dominant driver of ammonia volatilization; humidity had a secondary, temperature-modulated effect, with spray cooling providing only transient suppression.