Evaluation of corn germ and DDGS in diets fed to pigs
Two experiments were conducted to determine effects of inclusion of distillers dried grains with solubles (DDGS) and corn germ to diets fed to growing-finishing pigs on pig growth performance, carcass composition, and pork fat quality. The first experiment was conducted to investigate if negative impacts of DDGS on carcass fat quality may be ameliorated by addition of corn germ, tallow, palm kernel oil, or glycerol to growing-finishing pig diets. The second experiment was conducted to determine the optimal inclusion rate of corn germ in growing-finishing pig diets that contained 0 or 30% DDGS. In Exp 1, a total of 36 gilts and 36 barrows (initial BW: 43.7 ± 2.0 kg) were randomly allotted to 1 of 6 dietary treatments and housed individually. A corn-soybean meal control diet and a corn-soybean meal diet containing 30% DDGS were formulated. Four additional DDGS based diets containing 15% corn germ, 3% tallow, 3% palm kernel oil, or 5% glycerol were also formulated. There were no differences among diets in ADG, ADFI, or G:F of the pigs. However, gilts had less (P < 0.05) ADG and ADFI and greater (P < 0.05) G:F than barrows. Most carcass characteristics were not affected by dietary treatments, but pigs fed diets containing the control diet had greater (P < 0.05) loin eye area compared with pigs fed the DDGS diet. It was observed that BW, HCW, and back fat thickness were greater (P < 0.05) for barrows than for gilts, but fat free lean percentage was greater (P < 0.05) for gilts than for barrows. There were no dietary effects on loin muscle quality, but barrows had greater (P < 0.05) marbling and 24-h loin pH than gilts. Belly quality was not influenced by dietary treatments, but gilts had lighter (P < 0.05) bellies than barrows. Belly flop distance was greater (P < 0.05) for pigs fed the control diet than for pigs fed the 5 DDGS-containing diets. However, there were no differences among pigs fed the DDGS diets. Belly flop distance was greater (P < 0.05) for barrows than for gilts. There was a tendency (P = 0.07) for gilts to have greater backfat iodine value (IV) and greater (P = 0.05) belly fat IV than barrows. It was concluded that inclusion of corn germ, tallow, palm kernel oil, or glycerol to growing-finishing diets did not ameliorate the negative effects of DDGS on carcass fat quality. In Exp 2, a total of 280 pigs (initial BW: 42.5 ± 4.6 kg) were randomly allotted to 1 of 8 dietary treatments in a 2 × 4 factorial design with 2 levels of DDGS (0 or 30%) and 4 levels of corn germ (0, 10, 20, or 30%). Each diet was fed to 10 pens and either 3 or 4 pigs were housed in each pen. The pig from each pen that had a BW closest to the average BW for the pen was harvested at the conclusion of the experiment. Inclusion of corn germ to the diet did not affect pig growth performance regardless of the inclusion rate of DDGS, but ADG, ADFI, and final BW were reduced (P < 0.05) by inclusion of 30% DDGS to the diet. Carcass composition, muscle quality, and fat quality were not affected by inclusion of corn germ to the diets, but there was a reduction in LM marbling and firmness by inclusion of DDGS in the diets (P < 0.05). The L* value for back fat was reduced (P < 0.05) by inclusion of DDGS in the diet, but corn germ did not influence back fat color measures. Belly flop distance was reduced (linear, P < 0.001) as corn germ was added to diets containing no DDGS, but belly flop distance was not affected by inclusion of corn germ to diets containing 30% DDGS. However, there was a reduction (P < 0.001) in belly flop distance for pigs fed diets containing DDGS. It was concluded that pig growth performance, carcass composition, and muscle quality were not negatively affected by addition of up to 30% corn germ to diets containing 0 or 30% DDGS, but there was a reduction in belly firmness by inclusion of corn germ in diets containing no DDGS.
corn germ, distillers dried gains with solubles, fat quality, glycerol, oil, pigs
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign