PERFORMANCE, CARCASS YIELD, AND CARCASS QUALITY CHARACTERISTICS OF STEERS FINISHED ON RHIZOMA PEANUT (ARACHIS GLABRATA)-TROPICAL GRASS PASTURE OR CONCENTRATE

Steers (n = 156) finished on rhizoma peanut (Arachis glabrata Benth.)- tropical grass pasture in Florida and slaughtered at Central Packing, Center Hill were compared with steers (n = 152) finished on a concentr ate diet in Texas and slaughtered at Excel, Plainview. Average daily g ain during the growing and finishing periods was lower (P < .001) for forage-finished steers (.49 and .94 kg/d, respectively) than for conce ntrate-finished steers (.78 and 1.33 kg/d, respectively). Forage-finis hed steers had less fat over the ribeye (8.3 vs 11.4 mm; P < .01), lig hter hot carcass weight (280 vs 346 kg; P < .001), and smaller longiss imus muscle area (70.8 vs 86.6 cm(2); P < .001) than concentrate-finis hed steers. Yield grade was not different (2.7 vs 2.6; P > .10), but q uality grade was slightly better (low Select vs mid Select; P < .01) f or concentrate-finished steers. Lean color of forage-finished steers w as darker (P < .001) and fat of forage-finished steers had a creamier color (P < .001), but carcasses were not discounted due to yellow fat color. Shear force values were higher(6.8 vs 4.0 kg; P < .001) for for age-finished than for concentrate-finished steers. Off-flavors were de tected by trained sensory panelists in 36% of forage-finished and 14% of concentrate-finished carcasses, but all at barely detectable levels . This research indicates that steers can be finished on rhizoma peanu t-tropical grass pastures, but with some reduction in quality grade re lative to concentrate-finished steers. Fat color and off-flavor proble ms often associated with forage-finishing do not seem to be major conc erns when steers are finished on rhizoma peanut. However, dark lean co lor and poor tenderness of carcasses may reduce beef quality produced on this forage.