Effect of locally available and commercial preservatives on nutrient content, organic matter digestibility and microbial changes of wet brewers' grain

Abstract

The aim of the study was to evaluate the effect of different preservatives on nutrient content, organic matter digestibility (OMD), ammonia nitrogen (NH3-N), short-chain fatty acid (SCFA), yeast, mold, and lactic acid bacteria (LAB) concentrations of wet brewery grain (WBG). The experiment was undertaken for 28-days using five treatments (T); T1 = no preservative; T2 = 1.75% salt; T3 = 2.5% molasses; T4 = 2.5% Effective Microbial (EM) and T5 = 0.6% formic acid. Data was analyzed using a completely randomized two way factorial design of the mixed procedure of SAS (Version 9.1, 2001). The highest dry matter loss was for WBG stored with T1, while the lowest was for WBG treated with T5. WBG treated with T5 had the highest crude protein content, while those with T1 had the lowest. OMD of WBG treated with T5 was higher than T4. SCFA content of WBG treated with T3 was higher than those T4. WBG stored with T1 and T3 had a higher NH3N content than T4 and T5. WBG stored with T1 had the highest yeast and mold concentration, while WBG treated with T5 had the least. The highest LAB count was recorded for WBG treated with T5, while the least was for T1 and T3. Results has shown that preserving WBG with 0.6% formic acid is found to be more effective in terms of preventing spoilage by inhibiting mold and yeast growth as compared to other preservatives used in this study.