Evaluating the Impact of Different Seasons on the Air Quality Inside Some Pig Farms in Van Giang District of Hung Yen Province

This study was carried out at 3 pig farms in Van Giang district of Hung Yen province in winter and summer. Its aims to evaluate the influences of different seasons on the air quality inside the pigsty. The air quality was determined by some criterias: temperature, humidity, air speed, the concentration of CO2, H2S and NH3 around the pig house. Results of this research provide farmers with basic knowledge not only about designing and building pig cages but also rasing pigs suitably with different seasons. The results showed that, in both summer and winter, the value of temperature and humidity in pigsites was under permissible limits. Meanwhile, the concentration of CO2, H2S and NH3 were higher than permitted values. In summer, the the concentration of CO2, H2S, NH3 was higher than standard values (3.6 - 5.0; 2 - 26; 1.5 - 8 times respectively). In winter, the amount of these gases were higher the standard values (4.6 - 12.5; 2 - 26; 8.5 - 13.5 times respectively). In winter, the air quality was not good as that in summer with higher level poisonous gases (CO2: 1.2 to 1.5; H2S: 1.1 to 10; NH3: 1.1 to 6.3 times as compared with those in summer). Seasonal factor affected remarkably on indoor climate of pig house.