Effects of supplementing diets containing hulless barley varieties having different levels of non-starch polysaccharides with beta-glucanase and xylanase on the physiological status of the gastrointestinal tract and nutrientdigestibility of weaned pigs

Pigs (n = 78), weaned at 21 days, were used for determining the effects of beta -glucanase and xylanase inclusion, in feeds containing hulless barley, on performance and nutrient utilization in different parts of the gastroin testinal tract (GIT). The hulless barley varieties, Buck and Falcon, having high and low concentrations of beta -glucan and xylose, respectively were used with or without beta -glucanase (600 units/kg diet) and xylanase (745 units/kg diet) inclusions. Diets were provided for ad libitum consumption a nd blood samples were taken from the jugular vein. Weight gain and feed con sumption were recorded on days 5, 10 and 15. Six pigs per treatment were eu thanised on days 0, 5, 10 and 15, and digestive tracts were rapidly removed and divided by ligature into the stomach, three equal parts (proximal, med ial and distal) of the small intestine, caecum and colon. The digesta from each section were analyzed for viscosity, energy, non-starch polysaccharide , (NSP) and amino acids. Enzyme inclusion improved growth performance parti cularly for Buck. Enzyme treatment decreased (P < 0.05) the viscosity in th e distal part of the small intestine for pigs at days 5 and 10. Enzyme trea tment also reduced (P < 0.05) the plasma urea nitrogen concentration at day 10 and increased the apparent ileal digestibility of energy and some amino acids. These results suggest that NSP degrading enzymes are of benefit to early-weaned pigs fed diets based on hulless barley with high beta -glucan content. (C) 2001 Elsevier Science BY All rights reserved.