title: Effects of weaning age and diet on growth and carcass characteristics in steers.
abstract: Two experiments were conducted to determine the effects of diet on growth of steers weaned at approximately 100 vs 205 d of age. In Exp. 1, a 2 x 2 x 2 factorial experiment was conducted using 78 Angus crossbred cow-calf pairs. The factors examined were age at weaning (early, at 103+/-3 d [EW] vs normal, at 203+/-3 d [NW]), feeding strategy (ad libitum vs postweaning programmed intake), and dietary CP concentration (100 vs 120% of NRC [1984] recommended levels). Early-weaned calves had a greater (P < .001) ADG than NW calves from 103 to 203 d and reached market weight at 385 d vs 418 d for NW calves (P < .001). Likewise, steers offered feed for ad libitum consumption reached market weight at 394 d, compared with 409 d for programmed-intake steers (P < .05). In Exp. 2, 64 Angus crossbred steers were either weaned at 93+/-3 d and fed one of four diets, weaned at 210+/-3 d without access to creep feed, or weaned at 210+/-3 d with access to creep feed for 60 d prior to weaning. Early-weaned calves were heavier (P < .01) than NW calves at 210 d if fed either 100 or 90% concentrate diets, and they had greater (P < .001) backfat thickness at 210 d but no difference (P > .10) in longissimus muscle area compared to EW calves fed a 60% concentrate diet. At slaughter, 80 to 100% of steers on all treatments graded low Choice or higher. Feeding high-concentrate diets to EW beef calves accelerated growth rate and fat deposition early in the feeding period and may be a way to provide young cattle for a high-quality beef market.
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center and The Ohio State University, Wooster 44691, USA. fluharty.1@osu.edu
authors.forename: F L
authors.initials: FL
authors.lastname: Fluharty
authors.forename: S C
authors.initials: SC
authors.lastname: Loerch
authors.forename: T B
authors.initials: TB
authors.lastname: Turner
authors.forename: S J
authors.initials: SJ
authors.lastname: Moeller
authors.forename: G D
authors.initials: GD
authors.lastname: Lowe
mesh_terms: D000367:Age Factors; D000818:Animals; D001823:Body Composition; D002417:Cattle / Q000254:growth & development*; D004032:Diet; D004044:Dietary Proteins / Q000494:pharmacology; D004734:Energy Metabolism; D008297:Male; D008460:Meat / Q000592:standards*; D014886:Weaning; D015430:Weight Gain
chemical_list: D004044:Dietary Proteins