The effects of feeding sorghum dried distillers grains with solubles on finishing pig growth performance, carcass characteristics, and fat quality.

The objective of this study was to determine the effects of feeding sorghum dried distillers grains with solubles (DDGS) in grain sorghum­ or corn-based diets on pig growth performance, carcass characteristics, and carcass fat quality. A total of 288 finishing pigs (BW 58.8 ± 4.43 kg; Line TR 4 × 1050, PIC, Hendersonville, TN) were used in a 73-d study. Pigs were allotted to 1 of 6 dietary treatments with 6 pens of 8 pigs per treatment. Treatments included grain sorghum­based diets with 0%, 15%, 30%, or 45% sorghum DDGS (29.0% CP, 7.2% ether extract); a grain sorghum­based diet with 30% corn DDGS (25.7% CP, 8.7% ether extract); and a corn-based diet with 30% corn DDGS. The diets were formulated to 0.95%, 0.83%, and 0.71% standardized ileal digestible Lys in phases 1, 2, and 3, respectively, and were not balanced for energy. On d 73, a subsample of 72 pigs (1 barrow and 1 gilt/pen) was harvested at Kansas State University's Meats Laboratory. Carcass traits were calculated, as well as 10th-rib LM color, marbling and firmness, and fat color score. Fat samples from the 10th rib were collected and analyzed for fatty acid profile, which was used to calculate iodine value (IV). The remaining pigs were transported to a commercial packing plant (Triumph Foods, St. Joseph, MO) for carcass measurement and jowl IV determinations. Overall, increasing the dietary sorghum DDGS reduced (linear, P < 0.01) ADG and increased (linear, P < 0.01) back fat IV. Pigs fed increasing sorghum DDGS had decreased 10th-rib fat a* (less red) and b* (less yellow; P < 0.01 and 0.06, respectively). No differences were observed in growth performance or back fat IV among pigs fed corn- or grain sorghum­based diets with 30% corn DDGS. Pigs fed the grain sorghum­based diet with 30% corn DDGS had fat color that was more yellow (b*; P < 0.03) than that of pigs fed the grain sorghum­based diet with 30% sorghum DDGS. Pigs fed the grain sorghum­based diet with 30% sorghum DDGS also had decreased back fat IV (P < 0.01) and fat that was whiter (L*; P < 0.02) than that of those fed the grain sorghum­based diet with corn DDGS. Pigs fed grain sorghum with 30% sorghum DDGS had lower (P < 0.01) back fat IV than pigs fed corn with 30% corn DDGS. Feeding a grain sorghum­based diet with increasing sorghum DDGS reduces ADG when diets are not balanced for energy but, when fed at 30% of the diet, produces firmer pork fat than feeding a corn-based diet with 30% corn DDGS, which may be preferred for pork export markets.

Nutrient database for sorghum distillers dried grains with solubles from ethanol plants in the Western Plains Region and their effects on nursery pig performance.

Samples of sorghum distillers dried grains with solubles (DDGS) were collected and analyzed to establish a nutrient database and evaluate the quality and consistency between and within 5 ethanol plants in Kansas and Texas. Each sample (n = 21) was analyzed for AA, DM, CP, crude fiber, crude fat, ash, NDF, ADF, trace minerals, and starch. Mean values (DM basis) were 0.88% Lys, 10.49% crude fat, 34.21% CP, and 4,722 kcal/kg GE. The standard deviations among sorghum DDGS plants were similar to those within plants for most nutrients. Results of these analyses were used to formulate diets for 2 nursery trials. The 2 experiments were conducted to determine the effects of adding sorghum DDGS (29.0% CP and 7.2% crude fat) to corn- or sorghum-based diets on nursery pig growth performance. In Exp. 1, 360 nursery barrows (6.8 kg and 26 d of age) were used in a 34-d study. Pigs were allotted to 1 of 8 dietary treatments with 5 pigs per pen and 9 pens per treatment. Treatments were arranged in a 2 × 4 factorial with main effects of grain source (corn vs. sorghum) and sorghum DDGS (0, 15, 30, or 45%). Diets were formulated to 1.30 and 1.25% standardized ileal digestible (SID) Lys in phases 1 and 2, respectively, but were not balanced for energy. Overall, there were no differences among pigs fed sorghum- or corn-based diets for ADG and ADFI; however, as sorghum DDGS increased from 0 to 45% of the diet, ADG decreased (linear, P < 0.01). There was a DDGS × grain source interaction (linear, P < 0.04) observed for G:F. In corn-based diets, pigs fed increasing sorghum DDGS had relatively similar G:F. However, in pigs fed sorghum-based diets, G:F was best for those fed 0% DDGS but was decreased in pigs fed 15, 30, or 45% sorghum DDGS. In Exp. 2, 180 nursery pigs (10.7 kg and 38 d of age) were used in a 21-d study with 6 pigs per pen and 5 pens per treatment. Treatments were arranged in a 2 × 3 factorial with main effects of grain source (corn vs. sorghum) and DDGS (0 vs. 30% corn or sorghum DDGS). Diets were formulated to 1.27% SID Lys and were not balanced for energy. Overall, there were no differences in ADG among pigs fed sorghum- or corn-based diets as well as no differences among pigs fed sorghum or corn DDGS. Pigs fed diets with 30% DDGS gained less (P < 0.03) than pigs fed basal diets. These results indicate sorghum can be a suitable replacement for corn in nursery pig diets, but increasing sorghum DDGS decreased ADG.