Effect of Particle Size of Corn Silage on Digestibility and Rumen Fermentation

Abstract

Corn in early dent stage, of three theoretical cuts of .62, 1.27, and 1.91 cm was ensiled. Diets from each silage were balanced with other ingredients and fed to four mature sheep per diet in a completely randomized experiment to measure digestibility. In addition, each diet was fed to two mature fistulated dairy steers to determine effects on rumen fermentation. Digestibilities of dry matter were 71.8, 72.3, and 67.7% for the .62, 1.27, and 1.91 cm silage diets. There were no significant differences in any digestibilities due to cut of silage except digestion of nitrogen-free extract was reduced on the 1.91 cm cut diet. Volatile fatty acid concentrations (μmoles/ml of rumen fluid) for the same diets were 51, 80, 44 for acetate; 18, 23, 12 for propionate; and 10, 14, 7 for butyrate. For each acid the concentration on the 1.27 cm cut silage was highest, followed by the .62 cm and 1.91 cm cut diets. © 1979, American Dairy Science Association. All rights reserved.