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Because of rising corn prices and supply of distillers dried grains with soluble (DDGS), increasing the inclusion of DDGS on grower-finishing pig diets could be an economical option to reduce diet cost. But high amounts of this by-product may result in reduced growth performance and dressing percentage, and appearance of potential problems arising from soft fat. Thus, crossbred pigs (n = 512) with an average initial BW of 22.1 ± 0.54 kg were used to evaluate growth performance, carcass characteristics, and pork fat quality of grower-finishing pigs fed diets containing increasing content of DDGS. One of 4 dietary treatments was randomly assigned to each pen within sex. Dietary treatment and sex were the main factors in a 3-phase feeding program (BW = 22 to 53 kg, 53 to 85 kg, and 85 to 115 kg). Dietary treatment consisted of a corn-soybean meal control, or a corn-soybean meal diet containing 10, 20, or 30% DDGS.
Overall, increasing the dietary DDGS content had no effect on ADG (P = 0.74), but ADFI was linearly reduced and G:F was linearly increased (P = 0.01). Dressing percentage, LM marbling and firmness, and belly firmness were linearly reduced (P < 0.05) with increasing dietary DDGS. Subjective LM color score (P = 0.65), drip loss (P = 0.37), and ultimate pH of LM (P = 0.21) were not influenced by dietary DDGS. Feeding an increasing content of DDGS linearly increased (P < 0.05) PUFA concentration, particularly linoleic acid, in belly fat, backfat, and LM intramuscular fat, although the increase in LM intramuscular fat was smaller in magnitude (P < 0.05) than in backfat and belly fat. Pigs fed an increasing content of DDGS had a linear increase (P < 0.05) in the iodine value of backfat, belly fat, and LM intramuscular fat of 58.4 to 72.4, 61.5 to 72.3, and 54.8 to 57.7, respectively. Oxidation of LM intramuscular fat measured on d 0, 14, 21, and 28 of storage was not affected by dietary treatment. Taste tests for LM showed no effects of diet on flavor, off-flavor (P = 0.36), tenderness (P = 0.66), juiciness (P = 0.58), and overall acceptability (P = 0.52) scores. Similarly, bacon flavor (P = 0.88), off-flavor, crispiness, and overall liking scores were not affected by increasing dietary DDGS, but bacon fattiness (P < 0.01) and tenderness (P < 0.05) scores were linearly reduced.
In summary, these results showed no negative effects on growth performance or dressing percentage when growing-finishing pigs were fed diets containing up to 30% DDGS, but fat quality may not meet the standards of all pork processors when feeding diets containing more than 20% DDGS.
G Xu, SK Baidoo, LJ Johnston, D Bibus, JE Cannon, GC Shurson, 2010. Journal of Animal Science, 88:1398-1410. http://dx.doi.org/10.2527/jas.2008-1404