Fig. 3. 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 with Lys and no yucca (L + 0), a diet with 62.5 mg kg^–1 yucca product (L + 62.5), and a diet with 125 mg kg^–1 yucca product (L + 125). Diet effect (P = 0.885); time since cleaning within week linear covariate effect (P < 0.001).