The nutritive value for ruminants of thin stillage and distillers' grains derived from wheat, rye, triticale and barley

Abstract

A study was conducted to determine nutrient degradabilities of thin stillages and distillers' grains derived from wheat-, rye-, triticale- and barley-based ethanol production. In vitro protein degradabilities of wheat, rye, triticale and barley thin stillages were determined using a protease enzyme assay. One ruminally fistulated cow was used to determine ruminal nutrient degradabilities for wheat, rye, triticale and barley distillers' grains. Results of the in vitro study showed that the soluble protein fraction was highest for rye thin stillage and lowest for barley thin stillage. The degradation rate of the slowly degradable protein fraction was higher for wheat and triticale thin stillage than rye thin stillage and was higher for rye than barley thin stillage. Effective degradability of crude protein followed the order rye (659 g kg−1) > triticale (632 g kg−1) > wheat (608 g kg−1) > barley (482 g kg−1) thin stillage. Ruminal degradability of dry matter was highest for rye and lowest for barley distillers' grains. Ruminal degradability of dry matter was also higher for wheat than triticale distillers' grains. Crude protein from barley distillers' grains had a lower ruminal degradability relative to crude protein from wheat and rye distillers' grains. Ruminal degradability of neutral detergent fibre was highest for rye distillers' grains (470 g kg−1), intermediate for wheat and triticale distillers' grains (average 445 g kg−1) and lowest for barley distillers' grains (342 g kg−1). It was concluded that thin stillage and distillers' grains derived from barley had a lower nutritive value for ruminants compared with those derived from wheat, rye and triticale. © 2000 Society of Chemical Industry