title: Use of expected progeny differences for marbling in beef: I. Production traits.
abstract: Six Angus bulls with HIGH ( > .4) and six bulls with LOW ( < -.16) expected progeny differences (EPD) for marbling were used to evaluate the impact of marbling on progeny production and carcass traits. Bulls were randomly bred to MARC II (1/4 Hereford, 1/4 Simmental, 1/4 Angus, 1/4 Gelbvieh) composite cows in each of 2 yr to calve in the spring. At weaning, steers and heifers were separated and managed in different production systems. Steers (n = 131) were fed a growing diet (1.1 Mcal of NEg/kg) for 48 d followed by adaptation to a 93% concentrate finishing diet. Heifers (n = 125) were fed a growing diet (.79 Mcal of NEg/kg) for 191 d followed by adaptation to the same 93% concentrate diet. Steers and heifers from each treatment were slaughtered at two times spaced about 60 d apart within both years. Marbling EPD class had no effect on fat thickness, USDA yield grade, carcass weight, finishing daily gain, finishing DMI, or finishing efficiency (P > .18). More (P < .05) carcasses of calves from sires with HIGH EPD for marbling graded USDA Choice than from LOW EPD sires, 74% vs 47%, respectively. Angus sires can be selected to produce progeny that have increased ability to grade Choice without increasing yield grade or decreasing animal growth or feed efficiency.
authors.affiliation: Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Vieselmeyer
authors.forename: R J
authors.initials: RJ
authors.lastname: Rasby
authors.forename: B L
authors.initials: BL
authors.lastname: Gwartney
authors.forename: C R
authors.initials: CR
authors.lastname: Calkins
authors.forename: R A
authors.initials: RA
authors.lastname: Stock
authors.forename: J A
authors.initials: JA
authors.lastname: Gosey
mesh_terms: D000818:Animals; D001823:Body Composition / Q000235:genetics* / Q000502:physiology; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D001947:Breeding; D002417:Cattle / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D005260:Female; D005524:Food Technology / Q000191:economics / Q000379:methods / Q000592:standards*; D008297:Male; D008460:Meat / Q000592:standards*; D014481:United States; D016885:United States Department of Agriculture; D014886:Weaning