Up to 30% corn germ may be included in diets fed to growing-finishing pigs without affecting pig growth performance, carcass composition, or pork fat quality

A total of 280 pigs (initial BW: 42.5 ± 4.6 kg) were used to determine effects of adding corn germ (15.6% CP; 16.6% acid hydrolyzed ether extract; 21.7% NDF) to diets fed to growing-finishing pigs. Pigs were randomly allotted to 1 of 8 dietary treatments in a 2 × 4 factorial arrangement of treatments with 2 levels of distillers dried grains with solubles (DDGS; 0 or 30%) and 4 levels of corn germ (0, 10, 20, or 30%). Each diet was fed to 10 pens with either 3 or 4 pigs per pen. Pigs were fed phase 1, 2, and 3 diets for 28, 28, and 27 d, respectively. At the conclusion of the experiment, 1 pig in each pen that had a BW that was closest to the average BW for the pen was harvested. For the overall experimental period, regardless of the level of DDGS, there was no effect of corn germ on pig growth performance, but inclusion of 30% DDGS in the diet reduced (P < 0.001) ADG, ADFI, and final BW. There were no effects of corn germ on carcass composition, muscle quality, or fat quality, but LM marbling and firmness were reduced (P < 0.05) by inclusion of DDGS in the diet. The L* value of LM decreased (linear and quadratic; P < 0.05) as corn germ was included in diets containing no DDGS, but that was not the case when corn germ was added to diets containing 30% DDGS (corn germ × DDGS; P < 0.01). Inclusion of DDGS in the diet reduced (P < 0.001) the L* value for backfat, but there were no effects of corn germ on backfat color measures. Inclusion of corn germ in diets containing no DDGS increased belly length (quadratic; P < 0.05), but that was not observed if corn germ was added to diets containing 30% DDGS. There was also a decrease in belly flop distance as corn germ was added to diets containing no DDGS (linear; P < 0.001), but no effects of corn germ were observed in diets containing 30% DDGS. However, inclusion of DDGS in the diet reduced (P < 0.001) the belly flop distance. In conclusion, addition of up to 30% corn germ in diets containing 0 or 30% DDGS did not negatively affect pig growth performance, carcass composition, or muscle quality, but belly firmness was reduced.