Abstract: The objective of this study was to evaluate the effects of microecological preparation on ammonia emission in pig house and growth performance of pigs. A 7-day-long verification test of two commercially available microecological preparations ('Yiweikang' and 'Ruierkang') for feed additive use and a commercially available microecological deodorant ('Ruierjia') for environmental use was conducted in a pig house (NO. 1). Subsequently, a formal test was carried out in the followed schedule. The basal diet of the fattening pigs in the experimental pig house (NO. 2) was supplemented with 5‰ 'Yiweikang' and 2. 5% 'Ruierkang'. Furthermore, the spray liquid of 'Ruierjia' was sprinkled in the body surface of the pigs and around the different regions of the experimental pig house (NO. 2). A control group (NO. 3 pig house) was also included in the formal test. The fattening pigs in the control pig house (NO. 3) were fed with basal diet without addition of the microecological preparation, and the control pig house received no deodorant treatment. The formal test lasted for 60 days. The results showed that compared to the control pig house (NO. 3), the ammonia concentration of the experimental pig house (NO. 2) was reduced to 5. 6 mg/kg at the 3^rd day of experiment, with a removal rate of 70. 05%; during the experimental period, the average daily gain of the fattening pigs in the experimental pig house (NO. 2) was elevated by 23. 79%, the daily feed consumption was increased by 4. 45%, the survival rate was 2 percentage points higher, and the feed/meat ratio was decreased by 15. 83%. In conclusion, dietary supplementation and spraying of the microecological preparations can effectively remove the ammonia in pig house and can promote the growth performance of pigs.

Key words: microecological preparation, ammonia, pig, growth performance