Influence of Feeding Regime and Biological Type on Growth, Composition and Palatability of Steers

Abstract

Growth, feed efficiency and serial-slaughter data from 387 steers and rib chemical and palatability data from 240 steers were analyzed for the effects of biological type (small vs large) and five feeding regimes: A = winter growing ration (2.18 Meal ME/kg), summer grazing, 60%-forage finishing ration (2.84 Meal ME/kg); B = same as A, except 20%-forage finishing ration (3.11 Meal ME/kg); C = 96.6%-forage ration (2.40 Meal ME/kg); D = 96.6%-forage ration switched to 60%-forage ration; E = 60%-forage ration. Live weight gains were as expected from the energy density of the rations; however, feed efficiency measured on a pen basis did not differ (P>.05) among regimes or types. Composition of gain was markedly altered by regime; and a similar pattern of regime effects was found for all measures of fatness (A = B < C = D < E). Rate of retail product growth was apparently restricted only for the deferred feeding regimes (A and B). Estimated retail product adjusted to 300 kg carcass weight was 229, 233, 220, 220 and 210 kg for regimes A, B, C, D and E, respectively. Type by regime interactions were unimportant for both composition and palatability traits. Composition data adjusted to equal longissimus muscle fat suggested that placing young cattle directly into the feedlot on moderate-energy rations would minimize excess fat at equal quality grades. Palatability was somewhat reduced (P<.05) for steers directly off grass, but this difference seemingly disappeared by 49 days on feed. Regime effects on taste panel traits were unimportant (P>.05) when adjusted to either constant weight or longissimus muscle fat; however, Warner-Bratzler shear values were higher in regimes A and B at both of these endpoints. Large-type steers had slightly (P<.05) lower palatability scores at constant weight, but not at constant age or longissimus muscle fat endpoints. Copyright © 1977. American Society of Animal Science . Copyright 1977 by American Society of Animal Science.