Effect of dried distillers' grains from wheat on diet digestibility and performance of feedlot cattle

Gibb, D. J., Hao, X. and McAllister, T. A. 2008. Effect of dried distillers' grains from wheat on diet digestibility and performance in feedlot cattle. Can. J. Anim. Sci. 88: 659-665. In a 55-d backgrounding period, 120 British cross heifers (312 +/- 20 kg) received diets containing 55% barley silage, 5% supplement and 0 (n = 24), 20 (n = 24), or 40% (n = 72) wheat distillers' dried grains with solubles (DDGS). The remainder of the diet was steam-rolled barley. Replacing half (20%) or all (40%) of the barley with DDGS did not affect dry matter intake (DMI) (P = 0.61), average daily gain (ADG) (P = 0.86), or gain:feed (P = 0.94), indicating the energy content of DDGS is similar to that of barley when included in backgrounding diets. During a 133-d finishing period, DDGS were included at 0, 20, 40, or 60% of diet dry matter (DM) or at 60% plus additional calcium, provided as 1% limestone (n = 24). Additional calcium did not (P > 0.1) affect DMI, ADG, or gain:feed. Increasing levels of DDGS linearly increased (P = 0.001) DMI and reduced (P = 0.04) gain:feed and diet NEg content (P = 0.001), but had no effect on ADG (P = 0.20). Feeding 60% DDGS reduced (P < 0.01) DM digestibility as compared with the control. Wheat DDGS has similar feeding value as barley when included at 20% of diet DM, but digestibility and energy content decline with higher levels of inclusion.