Effects of Baking Hulless Barley on the Digestibility of Dietary Components as Measured at the Ileum and in the Feces in Pigs

The effects of different baking conditions on the apparent digestibility of dietary components were examined in pigs with an ileal cannula. The pigs were fed a hulless barley-based diet that was 1) uncooked, 2) baked for 4 h using high moisture, low temperature (37% dry matter, 121°C) conditions (HMLT), or 3) baked for 1 h using lower moisture, high temperature (48% dry matter, 204°C) conditions (LMHT). Ileal digesta and fecal dry matter were not different between the three diets. Pigs fed the HMLT and LMHT diets had 4% and 2% higher starch digestibility at the lieum, respectively, than did pigs fed the uncooked diet (P < 0.05). Total Klason lignin recovered at the terminal ileum was similar for all diets even though initial Klason lignin values for the LMHT diet were twice that of the uncooked or HMLT diet. Digestibility of non-starch polysaccharides (NSP) as measured at the ileum and in the feces of pigs fed the baked diets was about 10% higher than in pigs fed the uncooked diet (P < 0.1). The ratio of NSP ileal digestion:NSP digestion as measured in the feces was over 0.75 for all diets. Baking increased digestibility in the barley-based diet by increasing the digestibility of starch and dietary fiber. Increasing the severity of baking (LMHT) tended to decrease digestibility compared to the mild baking (HMLT), but not significantly.