Evaluation of dried distillers grains with solubles as a partial replacement of barley silage or barley grain in diets for lactating dairy cows

Feeding value of dried distillers grains with soluble (DDGS) as an energy source for lactating dairy cows was evaluated in two studies. A diet in which barley grain was replaced by DDGS at 20% of dietary dry matter (DM) did not affect milk yield but tended to increase rumen pH compared with the control diet. Diets in which barley silage was replaced by DDGS at 20% of dietary DM increased milk yield and decreased chewing time compared with the control diet in both studies, but decreased rumen pH and milk fat concentration in the second study, and the inclusion of alfalfa hay in place of barley silage at 10% of dietary DM did not alleviate those depressions. In conclusion, DDGS can be used as an energy source as a partial replacement of barley grain or barley silage in diets for lactating dairy cows.