At any time, the pig farm must strictly control the temperature and humidity of the pig house to ensure that the farm environment is suitable. In particular, the temperature of the pregnant and farrowing houses should be controlled within 28 ° C. If the temperature in the farm exceeds 37 ° C and no cooling measures are taken, the farm will easily induce disease. A series of symptom groups such as prenatal and postpartum low or anorexia, shortness of breath, depression, and fever can severely reduce the number of sows born prematurely, aborted, weak and litters, and lactating sows. Decreased quantity, poor milk quality, diarrhea and poor growth in piglets.