The aim was to reduce nitrogenous emissions from cow excreta while maintaining milk production levels by feeding diets designed to balance postruminally available methionine (M) and lysine (L). Twenty lactating Holstein cows were blocked by parity and days in milk and assigned to one of 4 dietary treatments using a randomized complete block design with 5 cows per treatment (n = 5). Diets were corn silage based and supplemented with varying amounts of rumen-protected M (Smartamine; RPM) and L (AjiPro-L 2; RPL). Diets included: A) 15% crude protein (CP) with low rumen protected amino acids (RPAA), B) 15% CP with high RPAA, C) 18% CP with low RPAA, and D) 18% CP with high RPAA. Diets were formulated to have similar metabolizable protein content with a 3:1 ratio of L:M for absorption. Milk samples were analyzed for fat, protein, and urea nitrogen (MUN); blood (BUN) and urine (UUN) for urea nitrogen. Urine and feces were collected from each cow on d 0, 14, and 28. Slurry sample emissions were measured over 72 h using flux chambers. Flux chamber emission measurements included methane (CH₄), nitrous oxide (N₂O), ammonia (NH₃), hydrogen sulfide (H₂S), and methanol (MeOH). Data were analyzed using the lmer statistical package in R, with an α of 0.05. Dry matter intake (A:24.3, B:22.8, C:25.0, D:25.8, kg) and milk yield (A:35.6, B:33.5, C:40.4, D:38.4, kg) were lower for the low vs high CP groups. High CP diets increased MUN (A:10.7, B:10.8, C:16.5, D:14.5, kg/dL), PUN (A:8.8, B:9.1, C:14.0, D:14.0, kg/dL), and UUN (A:686, B:654, C:891, D:1060, kg/dL), while RPAA had no effect. Crude protein, but not RPAA, effected both total nitrogen (A:0.66, B:0.63, C:0.75, D:0.75, %) and ammonia nitrogen (A:0.29, B:0.28, C:0.35, D:0.40, %) in the slurry. Gas emissions of NH₃ showed a day and time (A:284.4, B:279.6, C:302.4, D:363.5, mg/hr/m²) and N₂O a day effect (A:0.99, B:1.18, C:1.03, D:1.17, mg/hr/m²). Treatments were similar for CH₄ and MeOH, and H₂S decreased with increasing CP (A:0.10, B:0.05, C:0.05, D:0.04). Overall, precision feeding of RPAA had an effect on nitrogenous emissions over time (RPAA). Decreasing dietary CP concentration from 18 to 15% decreased concentrations of total slurry nitrogen, ammonia nitrogen, and UUN, MUN, and BUN.