Fig. 2. Ammonia emission rates as time after chambers were cleaned out progressed within each week. Three growing-finishing pigs in each chamber were fed a control corn and soybean meal diet (C), a reduced crude protein diet containing Lys (L), and a further reduced crude protein diet containing Lys, Met, Thr, and Trp (LMTT). Diet effect (P = 0.098); time since cleaning within week linear covariate effect (P < 0.001).