29 Impact of Extended Feeding Duration on Trained Panel Analysis of Locally Grown Beef

Abstract

The objective of this study was to evaluate the impact of increased finishing weights on trained panel analysis and Warner-Bratzler shear force (WBSF) values of locally grown beef. Angus crossbred steers (n = 48) at an average weight of 340.9 kg were divided among two treatments: short-fed (SF) = 522.7 kg average final weight and long-fed (LF) = 613.6 kg average final weight to simulate a beef direct marketing operation. Cattle were split into two pens (n = 12 calves/treatment in each pen) and each pen had access to four automated feeders, which were filled as needed for ad libitum intake. Body weights were recorded at 28 d intervals throughout the finishing process to determine harvest dates and measure cattle performance. Finished steers were transported to a commercial processing facility. A strip loin was collected from the right side of each carcass approximately 48 hours following harvest. Strip loins were wet aged in the absence of light for 21 d, then cut into 2.54 cm steaks and frozen at -20° C until analysis. Sensory evaluations and WBSF were conducted as outlined by the AMSA Sensory Guidelines to evaluate the traits of juiciness, beef flavor intensity, off-flavor intensity, connective tissue amount, myofibrillar tenderness and overall tenderness. Data were analyzed as a completely randomized design with the fixed effect of final cattle weight and the random effect of panel session. Peak internal temperature was included in the model as a covariate. Statistical differences were determined with α ≤ 0.05 and tendencies were observed between 0.06 to 0.09. No differences were observed between treatment groups for initial or sustained juiciness, myofibrillar tenderness, connective tissue amount or overall tenderness (P ≥ 0.140). Steaks from LF cattle produced lower WBSF scores (P < 0.05) compared with SF cattle. Additionally, steaks from LF cattle produced less off flavors (P = 0.05) than SF cattle. Long fed cattle steaks tended to have a greater beef intensity score (P = 0.08). These results indicate that while LF cattle produce more tender beef with more intense beef flavor and less off-flavors, SF cattle still provide a quality eating experience, with less feed input costs. However, if there are potential processing bottlenecks from reduced processing capacity, long fed cattle will also provide a high-quality eating experience as well.