title: Wheat middlings in high-concentrate diets: feedlot performance, carcass characteristics, nutrient digestibilities, passage rates, and ruminal metabolism in finishing steers.
abstract: We conducted two experiments to determine the feeding value and effects on diet digestibilities, passage rates, and ruminal metabolism of wheat middlings (WM) fed as a replacement for either the concentrate or roughage components of finishing diets of steers. In Exp. 1, 120 medium-framed steers were blocked by weight and randomly allocated to one of six treatments of high-concentrate diets: control (0%); 5, 10, or 15% pelleted WM replacing dry-rolled corn (DRC); and 5 or 10% pelleted WM replacing chopped alfalfa hay (ALF) components of the diet. Increasing WM replacement of DRC increased DMI (P < .01) and feed:gain ratio (FG; P < .05) linearly. A 9.2% increase in daily DMI and 10.1% increase in FG were observed at 15% of WM. Daily gain and final weight of the steers were not influenced by WM replacement of DRC. The WM replacement of ALF decreased (P < .01) daily DMI linearly, but it had no effect on ADG, final weight, or FG. In Exp. 2, six medium-framed steers, fitted with ruminal cannulas, were used in a 6 x 6 Latin square design with the same treatments as described in Exp. 1. Dry matter, OM, and starch digestibilities decreased (P < .01) by increasing replacement of DRC with WM, and replacing ALF increased DM and OM digestibilities linearly (P < .01). Wheat middlings could replace only up to 5% of DRC without reducing feed conversion efficiency and diet digestibilities, but complete (100%) or partial (50%) replacement of ALF increased digestibilities of DRC finishing diets.
authors.affiliation: Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0201, USA.
authors.forename: B S
authors.initials: BS
authors.lastname: Dalke
authors.forename: R N
authors.initials: RN
authors.lastname: Sonon
authors.forename: M A
authors.initials: MA
authors.lastname: Young
authors.forename: G L
authors.initials: GL
authors.lastname: Huck
authors.forename: K K
authors.initials: KK
authors.lastname: Kreikemeier
authors.forename: K K
authors.initials: KK
authors.lastname: Bolsen
mesh_terms: D000821:Animal Feed / Q000592:standards; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D002417:Cattle / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D004063:Digestion / Q000502:physiology*; D005285:Fermentation / Q000502:physiology; D005769:Gastrointestinal Motility / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D008297:Male; D000455:Medicago sativa / Q000592:standards; D009753:Nutritive Value; D011897:Random Allocation; D012417:Rumen / Q000378:metabolism* / Q000502:physiology; D014908:Triticum / Q000592:standards*; D015430:Weight Gain / Q000502:physiology; D003313:Zea mays / Q000592:standards