Nutrient digestion by dairy cows fed diets replacing starch with non- forage fiber

Abstract

Corn starch is used as the main energy source in lactating dairy cow diets. Feeding high levels of corn starch may be associated with negative health impacts on lactating dairy cows, such as ruminal acidosis and laminitis along with higher feed costs and lower income from reduced milk components. Dried distillers grains with solubles (DG), a co-product of the ethanol industry, is an excellent source of energy. Ranathunga et al. (2010) demonstrated that that incrementally reducing the amount of starch in a ration from a high of 29% to a low of 20% by adding DG resulted in similar milk production and composition by lactating dairy cows. The objective of the study was to evaluate the effect of replacing starch from corn with non-forage fiber from DG and soybean hulls on the nutrient flow to the omasum, ruminal nutrient degradability, total tract nutrient digestibility, and nitrogen partition of lactating dairy cows.