Impact of feeding de-oiled wet distillers grains plus solubles on beef shelf life 1

Research was conducted to determine the effect of feeding de-oiled wet distillers grains plus solubles (WDGS) on beef fatty acid profile, retail shelf life and development of oxidation products during retail display (RD). A total of 336 crossbred yearling steers (initial BW = 351.08 ± 19.05 kg) were fed 1 of 7 dietary treatments: an all corn control (1:1 blend of dry rolled and high moisture corn), 35%, 50%, or 65% inclusion of WDGS, either full-fat or de-oiled. Within each treatment 15 Choice carcasses were randomly selected (n = 105), strip loins were obtained, aged 7 and 21 d, and representative steaks from each strip loin were placed in RD conditions for 7 d. Fatty acid profiles were determined (mg/100 g tissue basis) and differences (P ≤ 0.05) were found in the C16:1, C18:1T, C18:2 and total polyunsaturated fatty acids (PUFA) among dietary treatments. Palmitoleic acid (C16:1) was predominant (P < 0.0001) in the corn control group, intermediate in the 35% de-oiled WDGS group, but no differences (P > 0.05) were observed between all other diets. Elaidic acid (C18:1T) was greater (P = 0.01) in the 65% full-fat WDGS group, least for the corn control group, and intermediate for all other diets. Linoleic acid (C18:2) was greater (P = 0.0001) in all 3 full-fat WDGS groups and 65% deoiled WDGS group (290.98 mg/100 g, on average), intermediate in the 50% and 35% de-oiled WDGS groups (231.08 and 227.16 mg/100 g, respectively) and least for the corn control group (177.70 mg/100 g). The PUFA content was greater (P < 0.01) in all 3 full-fat WDGS groups and 65% de-oiled WDGS group (337.13 mg/100 g, on average), intermediate in the 50% and 35% de-oiled WGDS groups (274.77 and 273.84 mg/100 g, respectively) and least for the corn control group (223.98 mg/100 g). Dietary treatment did not alter discoloration (P = 0.30) or lipid oxidation (P = 0.36). Shear force decreased with age and RD (P < 0.0001) but dietary treatment had no effect on shear force (P = 0.93). In general, feeding 35% and 50% deoiled WDGS had intermediate PUFA content relative to a corn control or full-fat WDGS diet. Feeding deoiled WDGS did not seem to increase beef shelf life and does not negatively alter beef quality parameters in relation to full-fat WDGS.