The objective of this study was to investigate whether reducing dietary crude protein (CP) concnetration decreases fecal volatile fatty acis (VFA), manure ammonia, emission and odor and fecal urinary phenolic metobilities. Six barrows were alotted on of 6 dietary treatments in a Latin square deisgn. Treatments consisted of four corn-soybean meal based diets containing 15, 12, 9, and 6% crude protein, a caesin based diet containing 15% CP and a protein free diet. The caesin based and prtoein free diet were used to determine basal endogenous contribution of VFA, phenolics, ammonia and manure odor. Pigs were housed individually in metabolsim crates to allow total collection of faeces and urine. Feaces and urine were analyzed for VFA and phenolic metabolite concentrations, respectively. Faeces and urine were then mixed, stored and fermented at room temperature for 30 days. For ammonia determination, headspace air was sampled from manur slurries at 24, 48, and 72 hours after fermentation. Slurry samples were placed into vials, capped and randomized before odor panel evaluation. Odor effensiveness was classified on severity 1 – non-offensive and 5 – extremely offensive. Reucing CP increased VFA concentrations but did not effect phenolic concentrations in the urine. Manur ammonia emission was reduced as dietary CP concentration decreased from 15-0%. The 15% diet had the least offensive manure with odor qualitative ranking of 2.58. Compared with the 15% CP diet, manure from the 9 and 6% CP diet was found to be more offesnive with odor qualitative rankings of 2.92 and 3.10 respectively. Odor qualitative rank for th 12% CP, potein free,and casein based diets did not differ from the 15% CP iet. These results indicate that recution in dietary CP concentrations decreases ammonia emissions but doesn’t reduce odor offesniveness.