Mitigation of ammonia emissions from pig production using reduced dietary crude protein with amino acid supplementation.

To mitigate ammonia (NH3) emissions from pig production and understand dynamic emission profiles, reduced dietary crude protein (CP) with amino acid supplementation was studied with 720 pigs in a 12-room research building for 155days that covered from weaned to finishing stages. The pigs were divided into three 4-room groups and fed with 2.1-3.8% reduced CP (T1), 4.4-7.8% reduced CP (T2), and standard (control) diets, respectively. Compared with the control group, T1 and T2 decreased manure volumes and manure NH4+-N concentrations. Group-mean NH3 emission from the control group was 68.9gd-1AU-1 (AU=500kg live mass). Emissions from T1 (46.7gd-1AU-1) and T2 (29.8gd-1AU-1) were reduced by 33.0% and 57.2% (p<0.05), respectively. Dynamic peak NH3 emissions appeared during the third nursery phase for T1 and T2, but delayed to the first grower phase for the control group.