In recent years, companies that produce distillers dried grains with solubles (DDGS) have begun to remove some of the corn oil for use in biodiesel production. Conventional DDGS contains 10-12% fat, compared with 6-9% in low-oil DDGS.

There is limited information about how oil concentration in DDGS influences the digestibility of energy, fiber, and fat when fed to pigs. Therefore, an experiment was conducted to determine the apparent total tract digestibility (ATTD) of energy, neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid hydrolyzed ether extract (AEE), as well as the concentrations of digestible energy (DE) and metabolizable energy (ME) in two sources of DDGS. One source was a conventional DDGS, and the other was Dakota Gold, a low-oil DDGS.

Materials and methods

Twenty four barrows with an average initial body weight of 17.3 kg were randomly allotted to three diets: a basal diet containing 97% corn, and two experimental diets containing 47% corn and 50% of either Dakota Gold DDGS or conventional DDGS.

After a seven day adaptation period, urine and feces were collected for five days. The ATTD of GE, DM, ADF, NDF, and AEE, as well as the concentrations of DE and ME, were calculated for each diet. Nutrient digestibility, DE, and ME values for the two sources of DDGS were then calculated using the difference procedure, and all values were adjusted to 88% DM.

Results

Dakota Gold DDGS contained 4,442 kcal/kg, compared with 4,831 kcal/kg in conventional DDGS (Table 1). The concentration of AEE in Dakota Gold was 6.82%, compared with 9.54% in conventional DDDS. Dakota Gold contained more CP than conventional DDGS (27.99% vs. 26.23%), and less NDF and ADF.

The ATTD of NDF, ADF, and AEE was less (P < 0.05) in Dakota Gold than in conventional DDGS. This may be because the technology used to produce Dakota Gold results in a lower concentration of the most easily fermented fibers in the resulting product.

The ATTD of GE was the same in Dakota Gold and conventional DDGS. The concentrations of DE and ME in Dakota Gold were 3,017 and 2,743 kcal/kg, respectively. These values were less than the DE and ME in conventional DDGS, which was 3,244 and 2,965 kcal/kg, respectively. It is likely that the reason for the lower values for DE and ME in Dakota Gold DDGS are a result of the reduced concentration of fat in the Dakota Gold DDGS.

Key points

• Conventional DDGS contains more GE, DE, and ME than Dakota Gold.
• The digestibility of GE is the same in conventional DDGS and Dakota Gold, but the digestibility of NDF, ADF, and AEE are all greater in conventional DDGS.
• When feeding Dakota Gold to pigs, additional fat may need to be added to increase the energy content of the diets.

Table 1. Chemical composition of two different sources of distillers dried grains with solubles (DDGS), adjusted to 88% DM

Table 2. Concentrations of DE and ME and apparent total tract digestibility (ATTD) of nutrients in corn and two sources of distillers dried grains with solubles (DDGS), adjusted to 88% DM

This report is based on unpublished research by Diego Rodriguez, Su A Lee, and H. H. Stein.