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

•Mitigating ammonia from a 720-pig research building was studied for 155 days.•Two crude protein (CP) reduced diets were compared with standard diet for the pigs.•Two groups of pigs fed with CP-reduced diets emitted 33% and 57% less ammonia.•Manure volumes and NH4+-N in manure decreased as the CP reduced in the feed.•Peak emissions occurred earlier in growth stages for the treated than the control.

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 155 days 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 68.9 g d−1 AU−1 (AU = 500 kg live mass). Emissions from T1 (46.7 g d−1 AU−1) and T2 (29.8 g d−1 AU−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.