Effects of reduced fat distillers grains with solubles and condensed distillers solubles on beef steer performance and carcass characteristics

Abstract Text: In this trial 60 yearling Angus-Simmental cross steers (464 ± 1.32 kg) were stratified by BW to 10 pens with 6 steers/pen to evaluate the feedlot performance and subsequent meat quality characteristics of steers fed reduced fat, modified wet corn distillers grains with solubles (DGS) (average crude fat = 7.3%) or corn condensed distillers solubles (CDS) (average crude fat = 5.7%).  Steers were fed one of four whole shelled corn (SC) based diets for 106 d containing 15% ground mature switchgrass hay (DM basis) and 73.26% SC (T1; N = 2), 20.0% CDS and 62.70% SC (T2; N = 3), 40.0% CDS and 42.29% SC (T3; N = 3) or 40.0% DGS and 42.55% SC (T4; N = 2).  At harvest LM samples from 2 steers in each pen were analyzed.  Diets T3 and T4 contained more (P = 0.0001) CP than T1 and T2 diets.  The T3 diet contained significantly lower DM, NDF and ADF, and higher (P = 0.0001) ether extract values than diets T1, T2 and T4.  Steers fed T3 had lower (P = 0.002) DMI, and similar ADG to steers fed T1, T2 and T4.  Steers fed T3 had higher (P = 0.02) G:F than steers fed T4, comparing 0.20 to 0.16, respectively.  No differences (P > 0.05) in carcass characteristics between treatments were observed.  Mean quality grade and yield grade were average choice and 3.3, respectively.  Lower (P = 0.02) Warner-Bratzler Shear Force of rib steaks were found for T4 compared to T3.  Minolta color value for lightness was higher (P= 0.05) at d 7 of aging for T3 compared to T4.  Fatty acid analysis showed no significant differences in SFA, PUFA, MUFA or PUFA:SFA among treatments.  Finishing steer diets containing 40% CDS can be fed with similar feedlot performance and carcass quality as diets containing 0 or 20% CDS, or 40% DGS.

Keywords: Finishing steers, condensed distillers solubles, reduced fat corn distillers grains