title: Effect of beta-glucans contained in barley- and oat-based diets and exogenous enzyme supplementation on gastrointestinal fermentation of finisher pigs and subsequent manure odor and ammonia emissions.
abstract: The objective of the current experiment was to evaluate the influence of dietary cereal sources of beta(1,3)(1,4)-d-glucan (beta-glucan) and enzyme supplementation on indices of environmental pollution from finisher pigs. An experiment with a 2 x 2 factorial arrangement of treatments was initiated to investigate the effect of dietary source of beta-glucan (barley vs. oats) and enzyme supplementation (no vs. yes) on nutrient digestibility, N utilization, intestinal fermentation, and manure odor and ammonia emissions from finisher boars (n = 4; BW = 73.9 kg; SD = 4.7). Sixteen boars were assigned to 1 of 4 dietary treatments (n = 4/treatment): 1) barley-based diet, 2) barley-based diet + exogenous enzyme, 3) oat-based diet, and 4) oat-based diet + enzyme. The enzyme supplement used contained endo-1,3(4)-beta-glucanase and endo-1,4-beta-xylanase. Experimental diets were formulated to contain similar concentrations of DE (13.5 MJ/kg) and digestible lysine (8.8 g/kg). Pigs offered oat-based diets had reduced digestibility of DM (0.795 vs. 0.849; SEM 0.007; P = 0.001), OM (0.808 vs. 0.865; SEM 0.007; P = 0.001), GE (0.806 vs. 0.845; SEM 0.006; P = 0.002), and NDF (0.233 vs. 0.423; SEM 0.033; P < 0.003) compared with those offered barley-based diets. Oat-based diets increased populations of Bifidobacterium spp. (7.26 vs. 6.38 log cfu/g of digesta; SEM 0.201; P = 0.005) and Lactobacillus spp. (6.99 vs. 6.18 log cfu/g of digesta; SEM 0.234; P = 0.022) in the proximal colon and decreased manure odor emissions [2,179.6 vs. 4,984.6 Ou(E)/m(3) (where Ou(E) refers to European odor units); SEM 653.7; P < 0.011] compared with barley-based diets. There was an interaction between cereal type and enzyme inclusion on manure ammonia emissions from 0 to 96 h (P = 0.050). Pigs offered barley-based diets containing an enzyme supplement had increased manure ammonia emissions compared with those offered unsupplemented barley-based diets. However, there was no effect of enzyme inclusion on oat-based diets. In conclusion, pigs offered oat-based diets harbored increased Bifidobacterium spp. and Lactobacillus spp. populations in the proximal colon and had decreased manure odor emissions compared with those offered barley-based diets. Enzyme inclusion had no effect on manure ammonia emissions from pigs offered oat-based diets.
authors.affiliation: School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Lyons Research Farm, Newcastle, Co. Dublin, Ireland.
authors.forename: C J
authors.initials: CJ
authors.lastname: O'Shea
authors.forename: T
authors.initials: T
authors.lastname: Sweeney
authors.forename: M B
authors.initials: MB
authors.lastname: Lynch
authors.forename: D A
authors.initials: DA
authors.lastname: Gahan
authors.forename: J J
authors.initials: JJ
authors.lastname: Callan
authors.forename: J V
authors.initials: JV
authors.lastname: O'Doherty
mesh_terms: D000641:Ammonia; D000821:Animal Feed; D000822:Animal Husbandry; D000818:Animals; D018554:Avena; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004063:Digestion / Q000187:drug effects / Q000502:physiology; D044644:Endo-1,3(4)-beta-Glucanase / Q000494:pharmacology; D043364:Endo-1,4-beta Xylanases / Q000494:pharmacology; D005285:Fermentation / Q000187:drug effects* / Q000502:physiology; D001467:Hordeum; D008297:Male; D008372:Manure; D009812:Odorants; D013552:Swine / Q000502:physiology*; D047071:beta-Glucans / Q000494:pharmacology
chemical_list: D008372:Manure; D047071:beta-Glucans; D000641:Ammonia; D044644:Endo-1,3(4)-beta-Glucanase; D043364:Endo-1,4-beta Xylanases