Performance, carcass yield, and carcass quality characteristics of steers finished on rhizoma peanut (Arachis glabrata)-tropical grass pasture or concentrate

Abstract

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 concentrate diet in Texas and slaughtered at Excel, Plainview. Average daily gain during the growing and finishing periods was lower (P < .001) for forage-finished steers (.49 and .94 kg/d, respectively) than for concentrate-finished steers (.78 and 1.33 kg/d, respectively). Forage-finished steers had less fat over the ribeye (8.3 vs 11.4 mm; P < .01), lighter hot carcass weight (280 vs 346 kg; P < .001), and smaller longissimus muscle area (70.8 vs 86.6 cm²; P < .001) than concentrate-finished steers. Yield grade was not different (2.7 vs 2.6; P > .10), but quality grade was slightly better (low Select vs mid Select; P < .01) for concentrate-finished steers. Lean color of forage-finished steers was 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 forage-finished than for concentrate-finished steers. Off-flavors were detected 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 peanut-tropical grass pastures, but with some reduction in quality grade relative to concentrate-finished steers.(ABSTRACT TRUNCATED AT 250 WORDS)