Effects of feeding a high-fiber byproduct feedstuff as a substitute for barley grain in the diets of dairy cows in early lactatio

The objective of this study was to evaluate effects of using wheat dried distillers' grains with solubles (DDGS) to replace barley grain in the diet on dry matter intake (DMI), milk production and rumen fermentation of early lactation dairy cows. Sixty-one Holstein cows including thirteen ruminally-cannulated cows were fed diets containing either barley grain or wheat DDGS at 17% of dietary dry matter for 12 weeks after calving. The hypothesis was that reducing dietary starch content by using DDGS would increase rumen pH, DMI, and milk production of early lactation cows. However, cows fed DDGS did not have higher rumen pH, DMI, or milk production, and tended to have higher plasma non-esterified fatty acid concentration. Wheat DDGS can be used as a partial substitute for grain in the diets of early lactation cows without affecting milk production, but it may be associated with the risk of exacerbating their energy balance.