Effects of frame size and time-on-feed on carcass characteristics, sensory attributes, and fatty acid profiles of steers.

Abstract

Weaned British x continental crossbred steers (n = 108, 7 to 8 mo of age) of medium or large frame were used in a replicated experiment with a 2 x 4 factorial arrangement of treatments over 2 yr. Management regimens consisted of backgrounding for 150 d and finishing for 0, 30, 60, and 90 d. Carcass data were collected, and samples from the longissimus muscle were analyzed for long-chain fatty acids, cholesterol, and the percentage of fat. Duration of finishing was a source of variation for hot carcass weight, marbling, percentage of kidney, pelvic, and heart fat, fat thickness, yield and quality grades, cooking loss, flavor intensity, and stearic, oleic, and linolenic acids (P < .05). Myristic, palmitic, and margaric acids were negatively correlated (P < .05) with juiciness and with "cowy" and "painty" taste characteristics. Frame score did not influence long-chain fatty acids; however, there was a relationship between long-chain fatty acids and management regimen. Results suggest that feeding steers a finishing diet up to 90 d after backgrounding for 150 d has a positive influence on carcass characteristics without affecting cholesterol.