Effects of USDA feeder grade and time-on-feed on carcass characteristics and cooked beef palatability

Yearling feeder steers (n = 128), selected to vary in frame size and muscle thickness, were fed for 100, 130 or 160 days and then slaughtered. USDA grade data were collected and cooked rib steaks were evaluated for palatability attributes. Frame size was positively related to carcass weight and longissimus muscle area and negatively related to all fatness measures and to USDA yield grade. Steaks from large-framed steers received the lowest sensory panel ratings for juiciness and overall palatability. Muscle thickness of feeder steers was positively related to all measures of carcass muscling. Steaks from thinly muscled (No. 3) steers received higher ratings for juiciness and overall palatability than did steaks from thickly muscled (No. 1) steers. Large-framed or thickly muscled (No. 1) steers produced the lowest percentages of carcasses with at least Choice quality. Although some statistically significant differences were observed when the data were sorted by frame size or muscle thickness, few real trends were evident that would be of value to cattle feeders.