Cattle-fed diets with insufficient forage fiber concentrations may be predisposed to various digestive disorders. It has been suggested that there is a minimal fiber requirement for high-grain diets that is influenced by fermentability of the feed, forage particle size, and grain processing. This study evaluated the impact of grain processing (dry- vs. steam-rolling) and concentration (5.7 vs. 6.6% of dietary dry matter by replacing silage with straw) of undigestible neutral detergent fiber (uNDF) on feed intake, ruminal pH, average daily gain, feed efficiency, and carcass traits of steers fed a high barley-grain finishing diet. Compared to dry-rolling, steam-rolling did not affect ruminal pH, growth performance, carcass traits, or the occurrence of liver abscess. Likewise, uNDF content did not have these parameters, but bunk attendance and meal duration were longer with high vs. low uNDF. Higher uNDF increased mean pH and reduced the duration that pH was <5.8 and 5.2, while increasing the concentration of acetate in ruminal fluid. Steam-rolling did not enhance the utilization of barley-grain as compared to dry-rolling in finishing beef cattle-fed a highly fermentable diet. However, increasing dietary uNDF concentration could be effective for modulating feeding behavior and reducing the risk of ruminal acidosis.

Read the full article in the Journal of Animal Science.