title: Effect of corn bran and steep inclusion in finishing diets on diet digestibility, cattle performance, and nutrient mass balance.
abstract: One metabolism trial and 2 finishing trials were conducted to evaluate the effects of adding corn bran and steep liquor (steep) in replacement of dry-rolled corn (DRC) on diet digestibility, cattle performance, and nutrient mass balance in open feedlot pens. The metabolism trial (Exp. 1) used 8 ruminally cannulated heifers in a 4 × 4 Latin square design and the 2 finishing trials used 128 steer calves fed for 167 d (Exp. 2) and 256 yearling steers fed for 126 d (Exp. 3). Dietary treatments for all trials included a DRC-based control (CON), 30% corn bran (30/0), 30% corn bran plus 15% steep (30/15), and 45% corn bran plus 15% steep (45/15), in which by-products replaced DRC and molasses in the diet (DM basis). Diets were not isonitrogenous or isoenergetic. In the metabolism trial, feeding the by-product diets produced greater rumen pH (5.95) than CON (5.76; P < 0.01). Total tract DM and OM digestibility were greater for heifers fed CON than the by-product diets (P < 0.01). Dry matter and NDF ruminal disappearance (%/h) of corn bran were numerically less for cattle fed the CON diet than the by-product diets (2.36 vs. 2.84 and 0.72 vs. 1.66, respectively). In the performance trials, steers fed the by-product diets consumed more DM (P = 0.06) and G:F was either similar for all diets in Exp. 2 (P = 0.56) or less for cattle fed 30/0 than the other diets in Exp. 3 (P = 0.05). Percent N loss was reduced in Exp. 2 by including corn bran in diets compared with CON (P < 0.01). However, in Exp. 3, no differences in percent N loss were detected among treatments (P = 0.16), but more N was removed in the manure from pens where steers were fed by-products (P = 0.01). Although steep did not improve diet digestibility, it was beneficial in maintaining cattle performance in the feedlot studies. Feeding corn bran in combination with steep increased manure N removed and N in compost, but decreased percent N lost during the winter months only.
authors: Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
authors: K M
authors: KM
authors: Sayer
authors: C D
authors: CD
authors: Buckner
authors: G E
authors: GE
authors: Erickson
authors: T J
authors: TJ
authors: Klopfenstein
authors: C N
authors: CN
authors: Macken
authors: T W
authors: TW
authors: Loy
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D004063:Digestion / Q000502:physiology*; D004734:Energy Metabolism; D009753:Nutritive Value; D012621:Seasons; D003313:Zea mays / Q000737:chemistry*