The objective of the experiment was to examine effects of a diet containing high corn distillers grain with solubles on manure characteristics and NH₃ emission in dairy cows. Eighteen cows were blocked by parity and DIM and cows in each block were assigned to the following treatments: CON, control diet; 2) DG, CON with distillers grain with solubles at 28.8% (DM basis) replacing mainly soybean meal. The experiment was conducted for 11 wk and feces and urine from individual cows were collected over 3 d in wk 11 (total 8 spot samples per cow). Fecal or urine samples were composited based on an equal volume basis and frozen at −20°C. Immediately before the manure incubation, composited feces and urine were thawed and sampled to determine manure characteristics. Manure was reconstituted according to daily fecal and urine excretion estimated using markers (indigestible NDF and creatinine, respectively) for individual cows. The manures (2 kg of each) were incubated using a multiple chamber system over 10 d to measure NH₃ and H₂S emissions. Due to the limited number of incubation chambers, 6 manures (3 per treatment) have been finished for incubation and sample analysis, and the data from 6 manures were analyzed using the MIXED procedure of SAS where block and incubation chamber within block were random effects and diet was a fixed effect. The ratio of feces to urine and the contents of manure total and volatile solids were not different among treatments. Manure from DG had lower pH (6.64 vs. 7.37; P < 0.01), tended to have lower N (5.2 vs. 5.9 g/kg manure; P = 0.06), and had greater S (1.0 vs. 0.5 g/kg manure; P < 0.01) compared with CON. During the 10-d incubation, NH₃ emission was considerably lower (353 vs. 639 mg/kg manure; P < 0.01) for DG vs. CON. However, H₂S emission over 10 d for DG was similar (5.4 vs. 4.4 mg/kg manure; P = 0.23) with that for CON. After the incubation, manure N concentration was greater (4.3 vs. 3.8 g/kg manure; P = 0.01) for DG vs. CON. In conclusion, manure from cows fed a high-DG diet decreased NH₃ emission mainly due to lower pH of manure.