Urinary Allantoin Excretion of Finishing Steers: Effects of Grain Adaptation and Wet Milling Byproduct Feeding

A metabolism trial investigated microbial protein supply for finishing cattle. In Phase I, cattle were adapted to a dry-rolled corn diet. Urinary allantoin excretion was positively correlated with TDN supply. In Phase II, cattle were fed that diet or diets with a portion of the corn replaced by one of two levels of the corn wet milling byproducts steep liquor or distillers’ solubles. Byproducts inclusion did not increase microbial crude protein supply, as measured by urinary allantoin excretion. Rumen pH also correlated with microbial crude protein supply