title: Efficacy of laidlomycin propionate to reduce ruminal acidosis in cattle.
abstract: Three trials were conducted to evaluate the efficacy of laidlomycin propionate (LP) to reduce the incidence and severity of ruminal acidosis in cattle fed high-grain finishing diets. In each trial, LP was fed at 0, 6, or 12 mg/kg of diet DM. In two acidosis-challenge trials, ruminally fistulated steers were fed (DM basis) a 50% concentrate diet and then fed a 95% concentrate diet at a specific intake (2.75% BW) or steers were dosed intraruminally with a 100% concentrate diet. Laidlomycin propionate did not alter ruminal pH or total acid concentrations, but in Trial 1 the 6 mg/kg level altered (P < .10) the molar proportions of the acids, increasing total ruminal VFA and decreasing ruminal lactate. In Trial 3, a finishing trial, LP reduced (P < .10) intake day-to-day variation of individually fed steers during a 13-d adaptation period from a 65 to a 100% concentrate diet, suggesting reduced incidence of subacute acidosis. Feed intake was lower (P < .05) during the first 13 d of the trial due to LP but was not affected over the entire trial. Laidlomycin propionate improved feed efficiency (gain/feed) when calculated on a live weight basis (linear, P = .05) or carcass weight basis (linear, P = .20). Laidlomycin propionate does not prevent ruminal acidosis, but it may reduce the severity of ruminal acidosis during adaptation to a 100% concentrate diet.
authors.affiliation: University of Nebraska, Lincoln 68583-0908, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Bauer
authors.forename: D W
authors.initials: DW
authors.lastname: Herold
authors.forename: R A
authors.initials: RA
authors.lastname: Britton
authors.forename: R A
authors.initials: RA
authors.lastname: Stock
authors.forename: T J
authors.initials: TJ
authors.lastname: Klopfenstein
authors.forename: D A
authors.initials: DA
authors.lastname: Yates
mesh_terms: D000138:Acidosis / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D000821:Animal Feed / Q000592:standards; D000818:Animals; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000503:physiopathology; D004032:Diet / Q000592:standards / Q000662:veterinary; D006863:Hydrogen-Ion Concentration; D007476:Ionophores / Q000592:standards / Q000627:therapeutic use*; D008297:Male; D008985:Monensin / Q000031:analogs & derivatives* / Q000592:standards / Q000627:therapeutic use; D012417:Rumen / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D012720:Severity of Illness Index
chemical_list: D007476:Ionophores; D008985:Monensin; C010208:laidlomycin