BOMB CALORIMETRY OF HIGH-MOISTURE MATERIALS

Studies were conducted to examine the influences of source and amount of primer and moisture content on determined calorie content and to quantitate energy losses which occur during the drying process. Water was added to portions of finely ground, oven-dried corn silage to produce standard samples containing approximately 35, 50, and 65% dry matter. Four primers were tested: two solids, benzoic acid and sucrose; and two liquids, n,n-dimethyl formamide and butyl cellosolve. Primers were added to supply 10, 17, 25, and 50% of the gross energy of the mixture. When various amounts and sources of primer energy were used, differences among determined calorie contents of corn silage samples which combusted were not statistically significant. Samples with 65% moisture required an amount of calories from a primer equal to those furnished by the sample, and samples with less than 45% moisture did not require addition of primer materials for complete combustion. Losses of energy from silages during drying were found to be variable but significant. Therefore, in feeding trials comparing dry with ensiled materials, estimation of the effeciency of utilization of dry matter is of questionable accuracy. © 1969, American Dairy Science Association. All rights reserved.