title: Effect of degradable and escape protein and roughage type on performance and carcass characteristics of finishing yearling steers.
abstract: We evaluated protein sources for finishing steers in two randomized complete block design experiments. Experiment 1 used 144 steers (334 kg) with 2 x 3 factorially arranged treatments. Basal diets contained .9% urea or 5.6% soybean meal (SBM) and were either not supplemented or supplemented with additional protein (2%) from blood meal-corn gluten meal (BMCG) or SBM. Steers fed urea-containing diets consumed 4.6% (P < .10) more feed than those fed SBM-supplemented basal diets. On the basis of carcass weights, steers fed diets containing SBM as the basal protein source were 3.8% (P < .10) more efficient than those fed urea-containing diets; supplying additional SBM improved gain efficiency (G/F) 4.3% (P < .10) compared with BMCG. In Exp. 2, 384 steers (367 kg) were fed diets containing 1.0% urea (DM basis) and 10% roughage as either sorghum silage (four diets) or alfalfa hay (two diets). Additional protein was either not provided or provided (2%) as SBM, sunflower meal (SFM), or a 50:50 (N basis) SBM:SFM blend in silage-containing diets; for diets containing alfalfa, additional protein was either not provided or provided (2%) as SBM. Averaged across roughage source, added SBM tended (P = .16) to increase ADG. Dressing percent decreased (P = .09) with added SBM but was higher (P = .04) with alfalfa as roughage source. Feeding alfalfa vs sorghum silage as the roughage source increased carcass adjusted ADG 4.3% (P = .06) and G/F 4.8% (P = .02). Supplementing high-grain diets with SBM enhanced diet utilization, but BMCG was of little value.
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-1600, USA.
authors.forename: C T
authors.initials: CT
authors.lastname: Milton
authors.forename: R T
authors.initials: RT
authors.lastname: Brandt
authors.forename: E C
authors.initials: EC
authors.lastname: Titgemeyer
authors.forename: G L
authors.initials: GL
authors.lastname: Kuhl
mesh_terms: D000375:Aging / Q000502:physiology; D000821:Animal Feed / Q000592:standards*; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology*; D004043:Dietary Fiber / Q000145:classification / Q000494:pharmacology*; D004044:Dietary Proteins / Q000378:metabolism / Q000494:pharmacology*; D019587:Dietary Supplements; D002523:Edible Grain / Q000378:metabolism / Q000592:standards; D008297:Male; D000455:Medicago sativa / Q000378:metabolism / Q000592:standards; D011897:Random Allocation; D013025:Glycine max / Q000378:metabolism / Q000592:standards; D014508:Urea / Q000378:metabolism / Q000592:standards; D003313:Zea mays / Q000378:metabolism / Q000592:standards
chemical_list: D004043:Dietary Fiber; D004044:Dietary Proteins; D014508:Urea