Nutritional and Fungal Load Dynamics of Fresh Brewers’ Grain Stored Under Aerobic Conditions

Abstract

Brewers’ spent grain (BSG) is the amplest by-product of the brewing process. Fresh BSG is currently used as low-cost cattle feed due to its microbiological instability and high perishability. While recent research has looked the effects of storage time and temperature on the characteristics of wet brewers grains (WBG) as ruminant feeds. Three storage temperatures (15°C, 20°C, and 25°C) and periods (2, 4 and 6 days) were arranged in a 3×3 factorial design. Surface spoilage was not apparent at 15 °C throughout the storage periods. Deterioration was not also observed at 20 °C until the fourth day of storage where slight mold growth was apparent. Extensive mold growth was detected late in the sixth day at 20° C and continued manifestations up until the last day of storage at 25°C. Changes in major nutrients, DM losses, and yeast and mold colony count were significantly affected by the interaction of storage temperatures and durations (P<0.05). Except for samples stored at 15° C, nutrients contents decreased concomitantly (exceptions are ADF, lignin, and loss in DM) with prolonged storage times (p<0.05) and increasing temperatures (p<0.05). Contrast analysis indicated that it would be safe to store under aerobic storage conditions and feed the WBG for dairy cattle.