High-energy forage and feedlot finishing impact on beef consumer acceptability and sensory characteristics in the upper Midwest

Abstract Text: The objective of this study was to determine consumer acceptability and sensory attributes of beef longissimus thoracis steaks from finishing steers grazing high-energy forages vs. fed a conventional feedlot diet. Steaks were from 32 steers fed 1 of 4 treatment diets including: mixed pasture (MIX); simple cereal grain/brassica mixture (SIMP); complex cereal grain/brassica mixture; and conventional feedlot ration (FLOT). All steers grazed a perennial mixed pasture diet prior to being assigned a treatment. Steers (n=8) were fed FLOT diet for 92 d.  Steers in the MIX (n=8), SIMP (n=8), and COMP (n=8) grazed respective pastures for 76 d. Steers from all treatments were slaughtered on the same day. Carcasses were aged 7 d prior to fabricating 2.54 cm thick steaks. Vacuum packaged steaks were aged for an additional 7 d, and frozen (-20 °C) until evaluation for marbling score, instrumental color, pH, and Warner Bratzler shear force. Consumer panelists (n = 106) evaluated fresh steaks aged 15 d for flavor, texture and firmness, juiciness, and overall acceptability using a 9 point hedonic scale (1 = dislike extremely, 9 = like extremely). Data were analyzed with Proc Mixed and Proc ANOVA (SAS 9.4) for sensory characteristics and consumer acceptability, respectively. Marbling scores of steaks from FLOT steers  (524.58) were greater (P < 0.01)  compared to MIX (447.50), SIMP (437.50), and COMP (427.50). There were no treatment differences (P > 0.05) for instrumental color, pH, and Warner Bratzler shear force. There were no correlations (P > 0.05) between marbling and Warner Bratzler shear force. Consumer panel results indicated steaks from steers fed FLOT diet had more preferable (P < 0.05) texture and firmness as well as overall acceptability (7.00 and 6.61) when compared to MIX (6.30 and 6.08) but was not different than COMP (6.63 and 6.21) and SIMP (6.69 and 6.51).  Panelists detected no treatment differences (P > 0.05) in the hedonic ratings of flavor or juiciness. Results indicate that steaks from steers finished on high-energy forages are comparable to those finished on a conventional feedlot diet. Additionally, the brassica-rich forage diets did not impart any noticeable off-flavors in the steaks when compared to steaks from diets without brassicas.

Keywords: sensory, forage-finished, consumer panel