title: Predicting red meat yields in carcasses from beef-type and calf-fed Holstein steers using the United States Department of Agriculture calculated yield grade.
abstract: Analyses were conducted to evaluate the ability of the USDA yield grade equation to detect differences in subprimal yield of beef-type steers and calf-fed Holstein steers that had been fed zilpaterol hydrochloride (ZH; Intervet Inc., Millsboro, DE) as well as those that had not been fed ZH. Beef-type steer (n = 801) and calf-fed Holstein steer (n = 235) carcasses were fabricated into subprimal cuts and trim. Simple correlations between calculated yield grades and total red meat yields ranged from -0.56 to -0.62 for beef-type steers. Reliable correlations from calf-fed Holstein steers were unobtainable; the probability of a type I error met or exceeded 0.39. Linear models were developed for the beef-type steers to predict total red meat yield based on calculated USDA yield grade within each ZH duration. At an average calculated USDA yield grade of 2.9, beef-type steer carcasses that had not been fed ZH had an estimated 69.4% red meat yield, whereas those fed ZH had an estimated 70.7% red meat yield. These results indicate that feeding ZH increased red meat yield by 1.3% at a constant calculated yield grade. However, these data also suggest that the calculated USDA yield grade score is a poor and variable estimator (adjusted R(2) of 0.31 to 0.38) of total red meat yield of beef-type steer carcasses, regardless of ZH feeding. Moreover, no relationship existed (adjusted R(2) of 0.00 to 0.01) for calf-fed Holstein steer carcasses, suggesting the USDA yield grade is not a valid estimate of calf-fed Holstein red meat yield.
authors.affiliation: Department of Agricultural Sciences, West Texas A&M University, Canyon 79016, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: Lawrence
authors.forename: N A
authors.initials: NA
authors.lastname: Elam
authors.forename: M F
authors.initials: MF
authors.lastname: Miller
authors.forename: J C
authors.initials: JC
authors.lastname: Brooks
authors.forename: G G
authors.initials: GG
authors.lastname: Hilton
authors.forename: D L
authors.initials: DL
authors.lastname: VanOverbeke
authors.forename: F K
authors.initials: FK
authors.lastname: McKeith
authors.forename: J
authors.initials: J
authors.lastname: Killefer
authors.forename: T H
authors.initials: TH
authors.lastname: Montgomery
authors.forename: D M
authors.initials: DM
authors.lastname: Allen
authors.forename: D B
authors.initials: DB
authors.lastname: Griffin
authors.forename: R J
authors.initials: RJ
authors.lastname: Delmore
authors.forename: W T
authors.initials: WT
authors.lastname: Nichols
authors.forename: M N
authors.initials: MN
authors.lastname: Streeter
authors.forename: D A
authors.initials: DA
authors.lastname: Yates
authors.forename: J P
authors.initials: JP
authors.lastname: Hutcheson
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D016014:Linear Models; D008297:Male; D008460:Meat / Q000592:standards*; D011237:Predictive Value of Tests; D014297:Trimethylsilyl Compounds / Q000494:pharmacology*; D014481:United States; D016885:United States Department of Agriculture / Q000592:standards*
chemical_list: D014297:Trimethylsilyl Compounds; C475840:Zilpaterol