IMPACT OF BEEF CATTLE DIETS CONTAINING CORN OR SORGHUM DISTILLERS GRAINS ON BEEF COLOR, FATTY ACID PROFILES, AND SENSORY ATTRIBUTES

¹ Department of Animal Science, University of Minnesota, St. Paul 55108-6111
² Department of Animal Science, Oklahoma State University, Stillwater 74078
³ Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506

^* To whom correspondence should be addressed. E-mail: deb.vanoverbeke{at}okstate.edu.

	Abstract

Strip loins from 236 carcasses from crossbred-yearling steers were collected on each of two harvest dates (Harvest 1 or 2) to determine effects of feeding corn or sorghum distillers grains (DG) on beef color, fatty acid profiles, lipid oxidation, tenderness, and sensory attributes. Dietary treatments consisted of a steam-flaked corn (SFC) diet without (control) or with 15% corn dry or wet DG (CDDG; CWDG) or sorghum dry or wet DG (SDDG; SWDG) and alfalfa hay (R). Additional treatments included SDDG or SWDG with no alfalfa hay (NR). In Harvest 2, steaks from steers fed SFC had lesser L*, but greater a* (P < 0.05) values than those from steers fed DG. When comparing sorghum and corn DG steaks, the same color differences were detected. Steals from steers fed sorghum DG had lower L*, but higher a* (P < 0.05) values than those from steers fed corn DG. Also, L* values in steaks from steers fed SWDG with R were higher (P < 0.05) than those from steers fed SWDG with NR. In Harvest 1, feeding DG increased (P < 0.05) omega-6 fatty acid concentrations when compared to SFC. In both harvest groups, feeding dry DG increased (P < 0.05) linoleic acid concentrations when compared to wet DG. In Harvest 2, feeding corn DG diets increased (P < 0.05) linoleic acid concentrations compared to sorghum DG diets. In addition, increased (P < 0.05) concentrations of -linolenic acid in steaks resulted from feeding SDDG or SWDG with R compared to those sorghum treatments with NR. In each harvest group, feeding DG increased (P < 0.05) the omega-6:omega-3 ratio when compared to SFC, and feeding corn DG increased (P < 0.05) this ratio when compared to sorghum DG. Furthermore, steaks from steers fed corn DG had greater (P < 0.05) concentrations of trans-vaccenic acid than those from steers fed sorghum DG. In Harvest 1, the CLA isomer 18:2, trans-10, cis-12 was greater (P < 0.05) in steaks from DG diets. On d 1 of retail display, steaks from steers fed SDDG with R in Harvest 2 had greater (P < 0.05) TBAR values than those from steers fed SDDG with NR. Feeding DG at 15% of the dietary DM did not affect sensory attributes or Warner-Bratzler shear force values. Feeding DG from either corn or sorghum as either a wet or dry by-product had no effect on beef sensory attributes.

Key Words: beef, distillers grains, meat quality, sensory traits