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A survey of dry-rolled corn particle size and fecal starch in U.S. feedlots
Optimizing grain processing practices in cattle feeding operations is critical to maximize feed efficiency. A survey was conducted to evaluate dry-rolled corn (DRC) processing practices on particle size distribution and fecal starch in finishing cattle. Twenty four feedlots across South Dakota, Minnesota, Iowa, Nebraska, Kansas, and Colorado participated in the study. Samples of dry-rolled corn, freshly voided feces, and the finishing diet were collected from each feedlot. Particle size distribution of dry-rolled corn samples was determined at the Kansas State University Feed Technology Innovation Center (Manhattan, KS) using a Tyler Ro-Tap Sieve Shaker. The average geometric mean particle size across all operations was 4.6 ± 0.87 mm with a range of 3.2 to 6.8 mm. Fecal starch content averaged 18.2 ± 6.84%; by-product inclusion level averaged 27.0 ± 14.26%; roughage inclusion level averaged 8.3 ± 1.82%; NDF levels averaged 18.7 ± 4.02% on a dry matter basis. Fecal starch values indicate the amount of undigested starch in the feces, which may be influenced by corn particle size. There may be an opportunity to increase the degree of grain processing in some feedlot operations to improve total tract starch utilization.
Keywords:
feedlot, grain processing, fecal starch