Effect of Pelleting and 13-glucanase Supplementation on the Ileal and Fecal Digestibility of a Barley-based Diet in the Pig 1,2

The influences of pelleting and 13-glucanase supplementation on the digestibility of dietary components in a barley-based diet were investigated in pigs fitted with cannulas in the terminal ileum. The diet contained 49.0% starch, 18.9% crude protein and 14.8% dietary fiber, with arabinoxylans (4.9%), mixed-linked ~-glucans (3.4%) and cellulose (3.3%) as the main fiber components. Pelleting increased mixed-linked 13-glucan solubility from 45 to 62%. Neither treatment influenced the ileal or fecal apparent digestibilities of dry matter (64 and 80%, respectively), energy (62 and 79%), crude protein (53 and 75%), crude fat (26 and 27%) or dietary fiber (58 and 72%). However, pelleting increased (P < .01) the pre-ileal apparent digestibility of starch from 91.5 to 95.3% and decreased (P < .03) that of ash from -10 to -23%, while increasing (P < .005) the fecal apparent digestibility of starch from 98.6 to 99.7%. The solubility of mixed-linked 13-glucans in ileal digesta was lower (P < .001) in pelleted (26%) than in unpelleted (58%) diets. ~-glucanase supplementation also increased (P < .05) the ileal apparent digestibility of starch, from 92.6 to 94.3%, and of mixed-linked 13-glucans, from 95.7 to 97.1%. Significant betweenpig differences in the apparent digestibility of dietary components were observed. In conclusion, treatments that disrupt the endosperm cell walls in barley can increase the proportion of the diet digested prior to the large intestine. (