Date of Award
Program or Major
Master of Science
Peter S Erickson
Two experiments were conducted to compare the deterioration of wet brewers grains (WBG) treated with an enzyme and bacterial inoculant (Silo-King GPX, Agri-King Inc., Fulton, IL). Another experiment investigated ruminal DM and CP degradability of samples taken from experiment 1. Wet brewers grains were divided into separate piles upon delivery. Silo-King GPX was added to WBG at 0 kg/kg (control), 0.45 kg/900 kg WBG, and 0.9 kg/900 kg WBG, mixed for 5 min, and then stored in bins. Piles were left for 28 d to simulate farm storage practices. Samples (300 g) were taken every 2 d, 20.3 cm below the surface and analyzed for nutrients, VFA, molds, yeasts, mycotoxins and clostridia. Treated piles had quadratic increases in fat, acetic and butyric acids and quadratic decreases in starch, Ca, Mg, K, and Mn concentrations. In experiment 1, piles treated with preservative had linear decreases in pH and increases in lactic acid. The log CFU of yeast, mold and clostridia were reduced linearly and quadratically in the treated piles. In experiment 3, treatment resulted in linear and quadratic increases for DM, starch and K concentrations. The log CFU counts for yeast and mold decreased linearly and quadratically with treatment. Crude protein decreased linearly, while lactic acid concentration increased with treatment. A quadratic increase in ADF concentration was observed, while fat, NDIP, Na and acetic acid concentrations decreased quadratically. Covering increased NDF, ADF, NDIP, K and tended to increase log CFU mold. Three non-lactating cannulated cows were used in a 3 x 3 Latin square to determine the DM and CP degradability of samples taken from experiment 1. Cows were fed a diet supplemented with WBG at a rate of 1 kg/d. Dacron bags containing 5.3 g of dried sample were incubated in the rumen for 0, 2, 4, 8, 12, 16, 24 and 48 h (2 bags/sample d). Treatment had no effect on ruminal DM or CP degradability of WBG. This study indicates that using Silo-King GPX may reduce spoilage of WBG, without altering the degradability of the feed.
Marston, Susan P., "Microbial and nutritional changes of wet brewers grains inoculated with a commercial preservative" (2007). Master's Theses and Capstones. 338.