Table 2. The summer temperature of the farrowing houses from 4 different pig farms

Year	Average temperature (°C±SD)	Lowest temperature (°C)	Highest temperature (°C)
Farm 1	26.2±1.77	22.3	28.6
Farm 2	25.9±1.56	24.6	26.5
Farm 3	26.8±2.12	23.7	31.3
Farm 4	27.5±2.35	23.5	33