Performance, Body Composition and Carcass Characteristics of Finishing Steers as Influenced by Previous Forage Systems

Abstract

To evaluate effects of previous forage systems on feedlot performance, yearling Hereford steers (average initial weight of 249 kg) were grazed on tall fescue (TF), smooth bromegrass-red clover (BG-RC) or orchardgrass-red clover (OG-RC) pastures before finishing. Serial slaughter was utilized during the first 2 yr of this study to determine changes in carcass characteristics throughout finishing, while steers were slaughtered at approximately 29% body fat during the third year. Steers grazing TF entered the feedlot at lighter weights and maintained lighter weights throughout finishing (P less than .05) even though dry matter intakes and feed conversions were similar (P greater than .05) among treatments. Steers that previously grazed TF had less (P less than .05) body fat, body protein, fat thickness and marbling, smaller (P less than .05) ribeye areas and lower (P less than .05) USDA yield and quality grades than than those that grazed BG-RC and OG-RC. However, linear contrasts indicated that steers grazing TF were compensating in ribeye area, marbling and quality grade as days in feedlot increased. This was confirmed in the third-year study, since carcass characteristics were similar among all steers. During the third year, linear and quadratic contrasts indicated that steers that grazed TF partially compensated in body protein. As days in feedlot increased, live and hot carcass weights, body fat, fat thickness, kidney, pelvic and heart fat, marbling, and USDA yield and quality grades increased (P less than .05), while ribeye area and body protein plateaued. Although carcass characteristics were similar among treatments, steers backgrounded on TF entered the feedlot at lighter weights, and partially compensated in weight after 134 d of finishing.

Stocker Growth on Rye and Ryegrass Pastures Affects Subsequent Feedlot Gains and Carcass Traits

“…However, the High and Medium gain steers had larger REA ( P < 0.05) than the Low pasture gain steers. These results were similar to that of Phillips et al (10) and Hancock et al (3). Hersom et al (4) reported no difference in REA among high and low gaining steers on wheat pastures.…”

“…Phillips et al (10) reported similar FAT and YG among high ADG and low ADG calves during the grazing period when fed to an equal fat thickness. In contrast, Hancock et al (3) reported lower fat thickness, YG, and MARB among low ADG performing animals during the grazing period when fed to a constant weight end point. Loken et al (6) fed two drylot energy rations to create two ADG levels, and concluded that the backgrounding ADG of 1.4 kg/day (low) or 1.7 kg/day (high) did not affect feedlot ADG, and that carcass traits were not affected by these pre‐feedlot ADG.…”

“…Sainz et al (11) restricted the growth of medium‐framed British type steers during the growing phase and observed increased intake and compensatory gains during the subsequent finishing period. Several have assessed various management systems or quality of forages on subsequent gain during the finishing period and effects on carcass traits (3,6,7,9,10). Neel et al (8) wintered stockers in drylot with restricted rations to create three gain categories, and concluded that stocker growth affected finishing performance and carcass quality.…”

Weaning and post-weaning performance by fall-born calves weaned on different dates from endophyte-infected tall fescue pastures managed with two different rotation frequencies

“…Numerous studies have evaluated feedlot performance following a grazing period on E+ fescue. Generally, cattle that previously grazed E+ pastures showed improved gain during a subsequent feedlot period (Coffey et al, 1990;Lusby et al, 1990;Allen et al, 2001;Cole et al, 2001b), but some studies have reported no improvement (Hancock et al, 1987) in feedlot gain or even reduced feedlot gain (Hancock et al, 1988) by calves that grazed E+ pastures previously. However, each of these studies used yearling cattle during post-weaning evaluations on E+ or other non-toxic forages.…”

An evaluation of production and economic efficiency of two beef systems from calving to slaughter1

“…Control steers had higher (P < 0.05) marbling scores than TRT steers. The improvement in marbling score observed in CON steers was a result of time on feed (Hancock et al, 1987;Van Koevering et al, 1995;Klopfenstein et al, 2000). The higher mar- bling score for the CON steers also implies that a higher percentage of steers would grade USDA quality grade Low Choice or greater compared with TRT steers.…”