Xylanase and fermentable xylo-oligosaccharides improve performance in grower-finisher pigs fed a corn-soybean meal based diet

Cecal inoculum collected from broilers fed a diet supplemented with xylanase showed increased gas production in an in vitro fermentation study with arabinoxylan-based substrates, indicating that intestinal microbiota can adapt to increase the capability to ferment arabinoxylans when pre-exposed to xylooligosaccharides (XOS) produced by xylanase. As the most abundant non-starch polysaccharides in a cornsoybean meal-based diet is arabinoxylan, this study tested the hypothesis that a blend of a xylanase and XOS will improve growth performance of pigs compared with those fed a diet supplemented with xylanase alone. One hundred twenty male crossbred (Landrace x Large white x Duroc) pigs (77 days average age; 30 kg average body weight -BW) were allocated to one of three treatments: CTR (control diet), XYL (CTR diet supplemented with 100 g/t of xylanase [Econase XT, AB Vista]) and XYL+XOS [CTR diet supplemented with 100 g/t of xylanase and XOS (Signis, AB Vista)]. Each treatment had ten replicates, with 4 animals each. The control diet was formulated with corn, soybean meal, DDGS and cassava meal as major ingredients. Pelleted diets were fed over 3 phases: grower (30-60 kg), finisher 1 (60-80 kg) and finisher 2 (80-100 kg). Average daily gain (ADG) and daily feed intake (ADFI) were measured from 30 to 100 kg and feed efficiency calculated (FCR). No treatment effects were observed on ADFI. Pigs offered the XYL+XOS had increased ADG (CTR = 1.058 vs XYL+XOS= 1.086 g/pig/d; P = 0.02) compared with those supplemented with xylanase alone (CTR = 1.058 vs XYL = 1.067 g/pig/d; P = 0.40). Feed efficiency was improved with XYL (2.65; P = 0.042) and XYL+XOS (2.60; P < 0.001) compared with CTR (2.71). These results suggest that xylanase in combination with XOS further improves daily gain and FCR compared with a xylanase alone. Interestingly the differences between XYL and XYL+XOS become more apparent in older animals, when the microbiome matures and possibly digests fiber more effectively.