Electrical stimulation (ES) is used in beef slaughter plants to improve tenderness; however, varying levels of low-voltage ES have not been well characterized. The objective was to evaluate the influence of two levels of low-voltage ES on temperature decline, pH, glycolytic potential, and meat quality. Forty-two beef carcasses were chosen from a commercial packing facility. One side of each carcass received either 40 or 80 volts of ES for 60 s at 45 min postmortem. The paired side of each carcass did not receive ES (Control). Temperature loggers were placed in the sirloin of 12 carcasses to record temperature decline. Longissimus muscle pH was measured at 1, 12, and 24 h, and 3 d postmortem. Strip steaks were fabricated for determination of meat quality. A treatment by time interaction was observed for carcass temperature decline (p < 0.001) where ES sides stayed warmer longer than Control sides. A treatment by time interaction was observed for pH decline with Control sides exhibiting an increased pH at 1 h postmortem (p < 0.001). Instrumental color values were increased for ES compared to Control sides (p < 0.001). These results indicate ES slows carcass temperature decline, hastens initial pH decline, and improves instrumental color. Similar results were observed between the ES treatments indicating either ES level may be used to achieve similar quality characteristics.

The objective of this study was to determine the influence of grain- and grass-finishing systems on carcass characteristics of bison bulls and proximate and fatty acid compositions of bison steaks. Bison bulls grazed native pasture until approximately 25 mo of age, then were randomly assigned to grain-finishing (n=98) or grass-finishing (n=98) treatments. Bulls were slaughtered at approximately 30 mo of age. Hot carcass weight (HCW), ribeye area, backfat thickness, kidney fat percentage, marbling score, and instrumental color (L*,a*, and b*) of the ribeye and subcutaneous fat were recorded. Skeletal maturity, lean maturity, and fat color were subjectively scored. Strip loins were collected from a sub-sample of carcasses, fabricated into 2.5-cm steaks, and designated for proximate, cholesterol, or fatty acid analyses. Grain-finished bulls had greater (P<0.0001) HCW, dressing percentage, ribeye area, backfat thickness, kidney fat percentage,and marbling score. The a* and b* values of the ribeye and a* value of subcutaneous fat were greater (P<0.0001), but the L* and b* values of subcutaneous fat were less (P<0.0001) for grain-finished bulls. A greater proportion (P<0.001) of grain-finished carcasses had moderately bright red lean color, whereas a greater proportion (P<0.0001) of grass-finished carcasses had moderately yellow fat color. Steaks from grain-finished bulls had an increased percentage of crude protein (P<0.0001), fat (P<0.0001), and ash (P=0.0006) content but less moisture (P<0.0001). Steaks from grain-finished bulls had more (P<0.001) cholesterol and palmitic, stearic, oleic, linoleic, and arachidonic acids in addition to more total fatty acids (mg/g of wet tissue). However, for total fatty acids, grass-finished steaks had a greater (P<0.0001) percentage of polyunsaturated fatty acids. These data indicate that the finishing system influences the composition of bison bull carcasses as well as the nutrient profile of bison meat.

Brassica cover crops have been widely used for improving soil health and as a feed resource for grazing cows, but their use in backgrounding diets is unknown. The objective of this study was to determine the impact of feeding a brassica cover crop mixture during backgrounding on beef palatability. Thirty steers were assigned to one of two dietary treatments during backgrounding with (1) ad libitum access to freshly cut brassica cover crop forage (CC) containing radish, turnip, rapeseed, and rye grass, or (2) common Midwestern dry lot backgrounding diet (CON). The steers were transitioned to a common finishing diet after backgrounding. Striploins were collected after harvest, and were analyzed for evaluation of the Warner–Bratzler shear force (WBSF), collagen content, autolysis of calpain-1, proteolysis of desmin, and troponin-T; in addition, the tenderness, juiciness, and flavor evaluated by a trained sensory panel. A treatment x day interaction was observed for WBSF (p = 0.02). Steaks from the CON diet were less tender than CC steaks on days 3 and 7, but did not differ on days 14 and 21. Feeding a brassica mixture cover crop during the backgrounding phase of production did not impact the collagen content, autolysis of calpain-1, or proteolysis of desmin and troponin-T. Thus, additional investigation into the mechanisms responsible for the differences observed in instrumental tenderness is warranted.

The objective of this study was to determine the impact of environmental temperature during subprimal transporton moisture loss, color, and tenderness. Cases of striploins (n=24) and sirloins (n=24) were placed on 2 pallets. Each pallet was loaded on a refrigerated truck prechilled to −2.2°C (−2.2FT) or 3.3°C (3.3FT) and transported for 12 h prior to arriving at the South Dakota State University (SDSU) Meat Laboratory. One subprimal was subset from each case for further analysis. Purge loss was measured prior to fabrication into eight 2.54-cm steaks. Steaks were overwrapped and packaged in modified atmosphere packaging prior to a second transport. Four steaks from each subprimal were placed on 1 of 2 pallets. Each pallet was placed on a prechilled refrigerated truck set at −2.2°C or 3.3°C. The steaks were transported for 12 h prior to returning to SDSU, subjected to case life analysis, and stored fresh or frozen. Steaks were evaluated for color, cook loss, purge loss, and Warner-Bratzler shear force. Data were analyzed as a split plot design with main effects of first transport temperature, second transport temperature, and aging day. Data from fresh and frozen product were analyzed separately. Purge loss was increased for 3.3FT sirloins compared with −2.2FT (P=0.0362). L* values for −2.2FT strip steaks were increased (P<0.0001) and purge loss decreased (P=0.0188) compared with 3.3FT steaks. L* values and fresh steak purge loss for 3.3FT sirloins were increased (P=0.0356 and P=0.0460, respectively) compared with −2.2FT steaks. These data indicate varied responses to temperature differences based on subprimal. Thus, a universal recommendation for all meat products could not be made. Further investigation into the impacts of transportation temperatures on various meat products is vital to optimization of the meat supply chain.

The objective of this research was to investigate the influence of beef hot carcass weight (HCW) on consumer sensory attributes. Beef carcasses (n = 116) were selected based on the USDA quality grade and HCW. Lightweight (LW; 296–341 kg), middleweight (MW; 386–432 kg), or heavyweight (HW; 466–524 kg) carcasses with USDA Choice (LC) or USDA Select (SEL) quality grades were used in this study. Carcasses were tracked through fabrication and the semitendinosus, chuck roll, and strip loin were collected and fabricated into eye of round, Denver cut, and strip loin steaks, respectively, for consumer sensory evaluation. USDA Select MW Denver cut steaks had increased overall liking and texture liking scores and were more tender and juicier than the SEL LW steaks (p ≤ 0.02). USDA Select MW strip loin steaks had increased overall and flavor liking scores and were more tender than the SEL LW steaks (p ≤ 0.02). USDA Choice MW eye of round steaks had increased overall, flavor, and texture liking scores and were juicier than the LW eye of round steaks (p ≤ 0.04). The steaks evaluated in this study were differentially impacted by HCW and little to no clear pattern of effects could be determined across cut or quality grade. Additional research is needed to determine the most acceptable HCW from a consumer perspective.