title: Effect of corn processing on degradable intake protein requirement of finishing cattle.
abstract: Three finishing trials were conducted to determine effect of corn processing on degradable intake protein requirement (DIP) of feedlot cattle. In Trial 1, 252 steers were fed 90% concentrate, high-moisture corn-based diets that contained 0, 0.4, 0.8, or 1.2% urea (DM basis) to provide dietary DIP values of 7.0, 8.2, 9.3, and 10.5% of DM, respectively. Nonlinear analysis predicted maximal feed efficiency at 10.2% dietary DIP (95% confidence interval was 9.9 to 13.3%). In Trial 2, 264 steers were fed 90% concentrate, steam-flaked corn-based diets that contained 0, 0.4, 0.8, 1.2, 1.6, or 2.0% urea (DM basis) to provide dietary DIP values of 4.7, 5.8, 7.0, 8.2, 9.3, and 10.5% of DM, respectively. Nonlinear analysis predicted maximal feed efficiency at 7.1% dietary DIP (95% confidence interval was 7.0 to 7.2%). In Trial 3, 90 individually-fed steers were fed 90% concentrate, dry-rolled, high-moisture, or steam-flaked corn-based diets. Urea was factored across diets at 0, 0.5, 1.0, or 2.0% of DM to provide dietary DIP values of 4.8. 6.3, 7.8, 9.2, and 10.7% for dry-rolled, 6.7,8.1,9.6, 11.1, and 12.5% for high-moisture, and 4.7, 6.1, 7.6, 9.0, and 10.5% for steam-flaked corn-based diets, respectively. For the dry-rolled corn-based diet, nonlinear analysis could not predict a requirement because feed efficiency was not improved beyond the first increment of dietary DIP, suggesting that the DIP requirement was met at 6.3% of DM. For the high-moisture corn-based diet, nonlinear analysis predicted maximal feed efficiency at 10.0% dietary DIP (95% confidence interval was 9.2 to 11.3%). For the steam-flaked corn based diet, nonlinear analysis predicted maximal feed efficiency at 9.5% dietary DIP (95% confidence interval was 9.2 to 9.5%). Our estimate of the DIP requirement for dry-rolled corn-based diets (6.3%) agrees well with past research and predicted values. Our estimate of the DIP requirement for high-moisture corn-based diets (10.1%) was very consistent between trials and higher than predicted. Our estimates of the DIP requirement for steam-flaked corn-based diets varied from 7.1 to 9.5%, with an average of 8.3% of dietary DM.
authors.affiliation: Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Cooper
authors.forename: C T
authors.initials: CT
authors.lastname: Milton
authors.forename: T J
authors.initials: TJ
authors.lastname: Klopfenstein
authors.forename: D J
authors.initials: DJ
authors.lastname: Jordon
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000254:growth & development / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage*; D005524:Food Technology / Q000379:methods*; D008297:Male; D009751:Nutritional Requirements; D011897:Random Allocation; D003313:Zea mays
chemical_list: D004044:Dietary Proteins