Effects of feeding distillers grains on beef quality

This research was conducted to understand the effects of feeding finishing diets containing distillers grains on beef quality. In the first and second studies, effects of feeding levels up to 30% of wet distillers grains plus solubles (WDGS) were studied on beef from calf-fed and yearling steers, respectively. In both experiments, feeding WDGS increased proportions of PUFA, omega 6, omega 6/omega3, and trans fatty acids when compared to corn (P ≤ 0.05). Additionally, a smaller proportion (P ≤ 0.05) of cis vaccenic acid (18:1, n 7) was observed in beef from animals fed WDGS. Lipid oxidation was higher in muscles from animals fed WDGS when compared to corn in both experiments (P ≤ 0.05). The third study examined the effects of feeding levels up to 50% of modified distillers grains plus solubles (MDGS) on fatty acid composition in beef. Linear increase ( P ≤ 0.05) was observed for PUFA and total trans as levels of MDGS increased in the diet. In the fourth experiment, effects on fatty acid profile of feeding 0 or 40% of WDGS and vitamin E (500 I.U.) were studied in cooked and raw muscles. Increased proportions of PUFA, trans, and omega 6 fatty acids were observed in beef from animals fed WDGS. The fifth study examined effects of feeding 35% of WDGS with vitamin E supplementation on lipid and color stability, sensory attributes, and WBSF. Additionally the effect of modified atmosphere packaging (MAP) of permeable film, high O2, and low O2 was also studied. Steaks from steers fed WDGS with no vitamin E had higher discoloration and lipid oxidation when compared to steaks from animals supplemented with 1000 I.U. of vitamin E. Lipid oxidation and WBSF values were higher in steaks displayed under high O2 when compared to permeable film and low O2. Feeding WDGS and MDGS increased PUFA, lipid oxidation and decreased color stability of beef. However, supplementation of 1000 I.U. of E mitigated the detrimental effects of feeding distillers grains on color and oxidation. High O2 MAP improved color stability, but a significant decrease in tenderness was observed when compared to the other MAP methods. Keywords: Beef, Distillers Grains, Vitamin E, Modified Atmosphere Packaging