Feed preferences and performance of nursery pigs fed diets containing various inclusion amounts and qualities of distillers coproducts and flavor

We evaluated the preferences of nursery pigs for diets containing increasing distillers dried grains with solubles (DDGS), varying in color, or high-protein distillers dried grains (HP-DDG) and the effects of flavor supplementation on pig preference and growth performance. In Exp. 1 through 5, diet preference was determined in weanling pigs adjusted to a commercial diet for at least 10 d, and then housed individually for a 2-d double-choice preference test. In Exp. 1, a total of 60 pigs (11.6 +/- 0.3 kg of BW) were given a choice between a reference diet (0% DDGS) and test diets containing 0, 10, 20, or 30% DDGS. In Exp. 2, a total of 80 pigs (10.8 +/- 0.1 kg of BW) were given a choice between a reference diet (0% HP-DDG) and diets containing 0, 10, 20, or 30% HP-DDG. In Exp. 3, a total of 80 pigs (10.3 +/- 0.2 kg of BW) were given a choice between a reference diet (0% DDGS) and a diet containing 0%, 30% light, or 30% dark DDGS. In Exp. 4, a total of 80 pigs (11.2 +/- 0.2 kg of BW) were given a choice between a reference diet without DDGS and a diet containing either 0% DDGS, 10 or 20% light DDGS, or 10 or 20% dark DDGS. In Exp. 5, a total of 108 pigs (9.0 +/- 0.2 kg of BW) were given a choice between a reference diet (0% DDGS and no flavor) and a diet without or with flavor and containing 0, 10, or 20% DDGS. In Exp. 1 and 2, DDGS and HP-DDG, respectively, linearly decreased (P < 0.01) pig preference. In Exp. 3, dark DDGS were preferred (P < 0.05) compared with light DDGS. In Exp. 4, preferences were linearly reduced (P < 0.01) with DDGS inclusion, and dark DDGS tended (P = 0.06) to be preferred compared with light DDGS. In Exp. 5, DDGS reduced preference (P < 0.01) and flavor reduced preference (P < 0.01) regardless of DDGS level. In Exp. 6, a total of 192 pigs (6.7 +/- 0.1 kg of BW) were fed starter 1 diets without or with flavor for 1 wk. Subsequently, pigs were fed starter 2 and 3 diets (2 wk each) containing 0, 10, or 20% DDGS while continuing to receive their respective flavor treatment. Flavor addition during the starter 1 phase increased ADFI (P = 0.02), and DDGS inclusion tended to decrease ADG (P = 0.06) and decreased ADFI (P = 0.03) during the starter 2 phase. Volatile components in DDGS and HP-DDG varied greatly depending on the source. Nursery pigs preferred a diet without DDGS or HP-DDG, and this appeared to be unrelated to color differences between sources. Knowledge of volatile compounds that enhance or suppress the palatability of feed may lead to further development of feed additives for masking relatively unpalatable, albeit cost-effective, ingredients.