Supplementation of barley-based diets with β-glucanase for pigs: Energy and amino acid digestibility response C. Kong and O. Adeola 1 Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 1 Corresponding author: ladeola@purdue.edu ABSTRACT: An experiment was conducted to determine the effect of graded levels of β-glucanase supplementation to barley (Hordeum vulgare)-based diets on the digestibility of DM, GE, N, and AA for growing–finishing pigs. Eight pigs (initial BW: 53.3 ± 3.2 kg) were each fitted with a simple T-cannula at the distal ileum and allotted to a replicated 4 × 4 Latin square design with 4 diets and 4 periods in each square. Diets were based on a barley–soybean (Glycine max) meal (SBM) basal diet (BD) containing 199 g CP and 3286 kcal DE per kilogram of diet. Treatments consisted of the BD and the BD supplemented with 10,000 (10K), 20,000 (20K), or 30,000 (30K) units of β-glucanase per kilogram at the expense of corn (Zea mays). Chromic oxide (0.5%) was included as an indigestible marker. Each experimental period consisted of 4 d of adaptation, 1 d of feces collection, and 2 d of ileal digesta collection. Apparent total tract digestibility (ATTD) of DM ranged from 81.0 to 82.5% and was not affected by β-glucanase supplementation. In the BD, ATTD of GE and N was 83.1 and 83.3%, respectively, and was not different in the BD supplemented with up to 30K units of β-glucanase per kilogram at 83.4 and 83%, respectively. Increasing levels of β-glucanase supplementation to the barley–SBM-based diet did not affect the ATTD of any criteria measured. Apparent ileal digestibility (AID) for DM, GE, and N ranged from 60.6, 65.4, and 70.8% (10K) to 66.4, 71.0, and 74.9% (20K), respectively. For indispensable AA, AID for Lys (79.9%) and Met (78.1%) was lowest in the BD supplemented with 20K and 10K units of β-glucanase per kilogram, respectively, and was not different from the digestibility of Lys and Met in the diet with added 30K units of β-glucanase per kilogram at 80.8 and 80.4%, respectively. There were neither significant linear nor quadratic effects of β-glucanase supplementation to barley–SBM-based diets on the AID of DM, GE, N, and AA. In conclusion, β-glucanase supplementation did not affect apparent ileal and total tract nutrient digestibility in grow–finish pigs fed a barley–SBM-based diet. Key words: amino acid, barley, β-glucanase, digestibility, ileal cannulated pigs © 2012 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2012.90:74–76 doi:10.2527/jas50543 INTRODUCTION Beta-glucans, which are present in the endosperm wall of barley, are composed of glucose molecules in long linear polymers with mixed β-(1→4) and β-(1→3) glycosidic bonds and have been identified as antinutritional nonstarch polysaccharides causing poor growth and nutrient digestibility in pigs. The supplementation of β-glucanase, which hydrolyzes β-glucan, to barley-based diets may improve growth and nutrient digestibility in pigs (Li et al., 1996). The efficacy of β-glucanase has been demonstrated in broiler studies (Hesselman and Åman, 1986; Ravindran et al., 2007). However, results from studies with pigs have been equivocal (Graham et al., 1989; Li et al., 1996). Moreover, there is a scarcity of information concerning the digestibility of AA in barley-based diets for growing pigs as influenced by β-glucanase supplementation. The current study was designed to determine the effect of graded levels of β-glucanase supplementation to barley– soybean meal (SBM)-based diets on the digestibility of DM, GE, N, and AA for growing–finishing pigs. MATERIALS AND METHODS All animal procedures were approved by the Purdue Animal Care and Use Committee. Animals and Dietary Treatments Eight Hampshire × Duroc × Yorkshire × Landrace barrows (initial BW 53.3 ± 3.2 kg) were each surgically fitted with a simple T-cannula at the distal ileum to Published January 23, 2015