Effects of Technology Use in Beef Production Systems on Meat Quality, Consumer Palatability and Muscle Dimensions of Strip Loins

Abstract

The objectives of this study were to examine the effect of beef production systems with and without the use of a beta-agonist on strip loin quality, consumer acceptance and muscle dimensions compared to an all-natural production system. The treatments include: all-natural (NAT), conventional (CONV), and conventional with zilpaterol hydrochloride (ZH; CONV-Z). Crossbred beef steers (n = 336) were randomized to one of three treatments and fed for an average of 136 d before slaughtered at Creekstone Farm; Arkansas City, KS. Forty-four carcasses that graded USDA Low Choice were identified for each treatment, loins were cut into 2.54-cm thick steaks, imaged, and aged for 14- and 21 d. Data were analyzed in the MIXED procedure of SAS and considered significant at P < 0.05. Analysis of Warner-Bratzler Shears (WBS) and slice shears (SS) showed CONV-Z steaks were tougher than CONV and NAT steaks regardless of aging. Outdoor consumer panelists found strip steaks from NAT and CONV-Z similar for tenderness, but less tender than CONV steaks (P < 0.05). No differences were found in juiciness, flavor and overall liking (P > 0.10). Trained panelists rated CONV-Z as less tender (P < 0.05) and less juicy (P < 0.05) than CONV or NAT steaks. Consumers were unable to detect tenderness or palatability differences found by WBS, SS and trained panelists. Conflicting consumer vs. trained panel results indicate consumers do not describe palatability differences in the same manner as trained panelists. Muscle dimension analysis indicated that longissimus lumborum (LL) area was increased in CONV-Z steers compared to CONV steers (P < 0.01) and CONV were increased compared to NAT steers (P < 0.01). Gluteus medius (GM) area was decreased in NAT steers compared to CONV-Z and CONV (P < 0.01). Maximum dorsal-ventral depth of LL at 25, 50 and 75% length of LL was increased in CONV-Z steers compared to CONV (P < 0.01) and NAT steers (P < 0.01), with the greatest increases at 25 and 75% depth. Results show improvement in muscle conformation creating a more usable center of the plate steak from the use of efficiency improving technologies.