A survey of dry-processed-corn particle size and fecal starch in midwestern United States feedlots1

Feedlots (n = 35) were asked to participate in a survey to evaluate dry-rolled corn processing practices, processed-corn particle-size distribution, and fecal starch content in finishing cattle. Feedlots were located in the central United States states of Kansas, Nebraska, South Dakota, Minnesota, Colorado, and Iowa. Samples of dry-processed corn and finishing diet were collected from each feedlot, along with samples of freshly voided feces collected from 3 pens of finishing cattle with samples collected from 3 animals per pen with a total of 9 samples per feedlot composited. Average particle size of dry-processed corn, including dry-rolled and hammermill-ground corn, across all operations (n = 35) was 4,223 ± 1,265 μm with a range of 1,165 to 6,823 μm. Dry-rolled corn average particle size (n = 31) was 4,534 ± 899 μm with a range of 2,167 to 6,823 μm. Hammermill-ground corn (n = 4) average particle size was 1,817 ± 1,158 fm with a range of 1,165 to 3,552 μm. Fecal starch content averaged 19.0 ± 6.5% with a range of 7.0 to 36.6%. Diet composition was evaluated for coproduct (27.8 ± 13.4%) roughage concentration (8.9 ± 2.0%).3 ± 4.3%). Data from this survey provide an indication of dry-rolled corn particle size and dietary formulation practices for feedlots located in the Midwest and Northern Plains regions of the United States. Fecal starch values indicate the amount of undigested starch in the feces, which may be influenced by corn particle size. Some feedlots may have the opportunity to increase the degree of grain processing to improve total-tract starch utilization.