A total of 860 finishing pigs (PIC C48/L42×327; initially 66.2 kg BW) were used in a 76-d experiment to evaluate the effects of removing corn DDGS from diets at increasing intervals before harvest. Diets contained 40% DDGS prior to the experiment, 0 or 35% DDGS during the experiment from approximately 66 to 82 kg and 0 or 30% DDGS until the completion of the trial.

Pen served as the experimental unit, and there were 7 replicate pens/treatment with 23 to 25 pigs/pen. Pens were blocked by BW and allotted to 1 of 5 dietary treatments, differentiated by the number of days prior to slaughter that diets containing DDGS were withdrawn and replaced with corn-soybean meal-based diets. Withdrawal times were 76, 42, 27, 15, or 0 d (no withdrawal) before harvest. Linear and quadratic response to withdrawal time was evaluated using PROC GLIMMIX. For the overall period (d -76 to 0), as the time of DDGS withdrawal increased, ADG and final BW also increased (linear, P < 0.018) and G: F improved (quadratic, P = 0.019). Average daily feed intake quadratically decreased (P = 0.030) with increasing withdrawal time. There was a linear increase (P = 0.010) in HCW, with a marginally significant increase in carcass yield (linear, P = 0.094) with increasing DDGS withdrawal time. Loin depth and lean percentage did not demonstrate any evidence for treatment differences (P > 0.132). Backfat was linearly increased (P = 0.030) with increasing DDGS withdrawal time. Lastly, iodine value (IV) of belly fat was increased (linear, P = 0.001) with increased feeding duration of DDGS.