The effect of pelleting, salt, and pentosanase on the viscosity of intestinal contents and the performance of broilers fed rye.

An experiment was conducted to determine the impact of pelleting of rye, dietary salt (.39 and .57%), and crude pentosanase supplementation (0 and .2%) on the viscosity of intestinal contents and the concomitant performance of broiler chicks fed rye-based diets. Each treatment was replicated six times with six birds per replicate. Test diets were fed from 1 day to 3 wk of age, at which time body weight, feed intake, intestinal viscosity, and molecular weight distribution of carbohydrate complexes were determined in fore and hind gut sections. Enzyme supplementation in all treatment combinations significantly increased weight gains and feed conversion efficiency (FCE). Pelleting and salt did not influence weight gain or FCE, although feed intake was increased through the addition of salt. The viscosity of fore and hind gut contents was significantly reduced with pentosanase supplementation, whereas the effects of salt or pelleting were not as clearly defined. Weight gain and FCE correlated with fore but not hind gut viscosity. The viscosity of gut samples was found to be best described by the concentration of carbohydrate complexes with an average molecular weight greater than 500,000 Da. Pentosanase treatment reduced lumenal concentration of these complexes, thereby reducing viscosity and stimulating improvements in growth and FCE.