title: Manipulation of dietary protein and nonstarch polysaccharide to control swine manure emissions.
abstract: Odor and greenhouse gas (GHG) emissions from stored pig (Sus scrofa) manure were monitored for response to changes in the crude protein level (168 or 139 g kg(-1), as-fed basis) and nonstarch polysaccharide (NSP) content [i.e., control, or modified with beet pulp (Beta vulgaris L.), cornstarch, or xylanase] of diets fed to pigs in a production setting. Each diet was fed to one of eight pens of pigs according to a 2 x 4, full-factorial design, replicated over three time blocks with different groups of animals and random assignment of diets. Manure from each treatment was characterized and stored in a separate, ventilated, 200-L vessel. Repeated measurements of odor, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions from the vessels were taken every two weeks for eight weeks. Manure from high-protein diets had higher sulfur concentration and pH (P < or = 0.05). High-NSP (beet pulp) diets resulted in lower manure nitrogen and ammonia concentrations and pH (P < or = 0.05). Odor level and hedonic tone of exhaust air from the storage vessel headspaces were unaffected by the dietary treatments. Mean CO2 and CH4 emissions (1400 and 42 g d(-1) m(-3) manure, respectively) increased with lower dietary protein (P < or = 0.05). The addition of xylanase to high-protein diets caused a decrease in manure CO2 emissions, but an increase when added to low-protein diets (P < or = 0.05). Nitrous oxide emissions were negligible. Contrary to other studies, these results do not support the use of dietary protein reduction to reduce emissions from stored swine manure.
authors.affiliation: Department of Agriculture, Food, and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB, Canada, T6G 2P5. grant.clark@ualberta.net
authors.forename: O Grant
authors.initials: OG
authors.lastname: Clark
authors.forename: Soenke
authors.initials: S
authors.lastname: Moehn
authors.forename: Ike
authors.initials: I
authors.lastname: Edeogu
authors.forename: Jason
authors.initials: J
authors.lastname: Price
authors.forename: Jeremy
authors.initials: J
authors.lastname: Leonard
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000821:Animal Feed / Q000032:analysis*; D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008372:Manure / Q000032:analysis*; D008697:Methane / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis; D009812:Odorants; D011134:Polysaccharides / Q000032:analysis; D013455:Sulfur / Q000032:analysis; D013552:Swine / Q000502:physiology*; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D004044:Dietary Proteins; D008372:Manure; D011134:Polysaccharides; D002245:Carbon Dioxide; D013455:Sulfur; D009609:Nitrous Oxide; D008697:Methane