Effects of 35% corn wet distillers grains plus solubles in steam-fl aked and dry-rolled corn-based fi nishing diets on animal performance, carcass characteristics, beef fatty acid composition, and sensory attributes1

Fifty-four individually-fed HerefordAngus cross steers (initial BW = 308 ± 9 kg) were used in an unbalanced randomized block design with a 2 × 2 factorial treatment arrangement to determine effects of corn processing method and corn wet distillers grains plus solubles (WDGS) inclusion in fi nishing diets on animal performance, carcass and beef characteristics, and sensory attributes. Dietary treatments included steam-fl aked corn(SFC) and dry-rolled corn (DRC)based fi nishing diets containing 0 or 35% WDGS (DM basis; 0SFC and 35SFC, 0DRC and 35DRC, respectively). Yellow grease was used to equilibrate fat content of diets. Steers were fed 174 d, and were harvested on a single date when the mean ultrasound fat thickness was estimated to be 1.30 cm. No interactions between corn processing and WDGS were observed for performance or carcass characteristics (P ≥ 0.11). Final BW (556 ± 14 kg) and ADG (1.43 ± 0.06 kg) were not affected (P ≥ 0.25) by dietary treatment. Steers fed SFC-based diets consumed less feed, and were 10.6% more effi cient (P < 0.01) than those fed DRC-based diets. Including WDGS in fi nishing diets improved feed effi ciency of steers consuming both SFCand DRCbased diets (P ≤ 0.04). Dietary treatment did not affect HCW, dressing percentage, fat thickness, or yield grade (P ≥ 0.27). Including WDGS in fi nishing diets decreased the concentration of 16:1cis-9, 18:1cis-9, and 18:1cis11 fatty acids, and tended (P ≤ 0.10) to increase total fat concentration of steaks compared with diets without WDGS. A corn processing method by WDGS interaction was detected for 18:1trans-11 where steaks from 0DRC diets had decreased concentrations compared with other diets. There were no dietary effects on palatability attributes (P > 0.20). Livery–organy aromatics (P = 0.03) and sweet basic tastes (P = 0.01) in steaks from the 35SFC treatment were more intense than in other treatments, but were barely detectable. Thiobarbituric acid reactive substances tended to be greater in steaks from steers fed WDGS after 5 d of storage (P = 0.10), and were greater after 7 d. (P < 0.01). Inclusion of WDGS used in this experiment improved G:F with minimal impacts on carcass characteristics. Both WDGS inclusion and corn processing method impacted fatty acid composition. However, diet had minimal impacts on palatability attributes. When compared with diets fat-equilibrated with yellow grease, the primary concern with incorporating WDGS appears to be decreased shelf-life after 5 d of storage.