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) barleybased diet + exogenous enzyme, 3) oat- based diet, and 4) oat- based diet + enzyme. The enzyme supplement used contained endo-1,3(4)-beta-glucanase andendo-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 barleybased 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 barleybased 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.
