Effects of a Multi-Element Trace Mineral Injection and Dietary Vitamin E Supplementation on Performance, Carcass Characteristics, and Color Stability of Strip Steaks from Beef Heifers

The objective was to evaluate the interaction of a trace mineral injection (Multimin 90; TM) and a supranutritional level of dietary vitamin E (VITE) supplementation on performance, carcass characteristics and color stability of strip steaks from beef heifers. Prior to trial initiation, Angus × Simmental crossbred heifers (N = 48) were managed on a common, trace mineral maintenance diet. Heifers were stratified by BW and allotted to 1 of 4 treatments in a 2 x 2 factorial arrangement: 1) saline injection and no additional vitamin E in the diet, 2) trace mineral injection and no additional vitamin E in the diet, 3) saline injection and 2000 IU Vitamin E heifer^-1 d^-1, or 4) trace mineral and 2000 IU Vitamin E heifer^-1 d^-1. Trace mineral injection (1 mL/68 kg BW) or saline injection were given once at the beginning of the 89 d finishing period. Diets contained 35% dry rolled corn, 35% modified wet distillers grains plus solubles, 20% corn silage, and 10% supplement. Cattle were slaughtered as one group and strip loins collected postmortem. Strip steaks were cut from each carcass and placed in overwrap trays for serial evaluation of color stability for 16 d. Data were analyzed using the MIXED procedure of SAS with fixed effects of VITE and TM, their interaction, and pen included as a random effect. Color stability data were analyzed as repeated measures. Trace mineral injection and VITE had no effect on final BW, DMI, or G:F (P ≥ 0.12). Trace mineral injection and VITE had no effect on HCW, yield grade, 12^th- rib backfat thickness, or ribeye area (P ≥ 0.34). Marbling scores tended to increase (P = 0.08) in VITE heifers compared heifers not supplemented VITE. Vitamin E supplementation reduced final lipid oxidation (1.00 vs. 1.97 µg MDA/g fat, P = 0.03) and total visual discoloration (15.82 vs. 33.96%, P = 0.04) of steaks compared with steaks from non-supplemented heifers. Heifers fed supranutritional levels of VITE produced steaks that maintained retail color longer evidenced through lower hue angle values (38.17 vs. 38.66°, P < 0.01) than heifers not supplemented with VITE. Interestingly, steaks from heifers receiving TM had greater visual discoloration (27.68 vs. 22.09%, P < 0.05) at the end retail display compared with steaks from heifers receiving saline injection. Overall, VITE supplementation improved color stability and TM appeared to increase the rate of discoloration of strip steaks from beef heifers.