The ethanol industry produces a variety of co-products, ranging from dehydrated corn germ meal to corn bran, with high-oil distiller's dried grains with solubles (DDGS) being approximately 31 per cent crude protein (CP), 12 per cent ether extract (EE), and 44 per cent neutral detergent fibre (NDF), according to W.A. Dozier, III and J.B. Hess of Auburn University.

They explain that, with the ethanol industry seeking alternate profit streams from ethanol plants and the biodiesel industry seeking alternatives to high-priced soybean oil, one potential additional product is corn oil extracted from existing ethanol plants. In extracting the oil in DDGS, crude fat levels can drop from approximately 12 per cent to six per cent EE, while in contrast, concentrations of other nutrients in the resultant reduced-oil DDGS are increased.

The objectives of this study, sponsored by US Poultry & Egg Association were to

1. determine metabolisable energy (AMEn) and amino acid (AA) digestibility of three sources of DDGS and
2. examine growth and meat yield responses of broilers fed diets consisting of three sources of DDGS fed to different inclusion levels from one to 35 day and one to 49 day of age. Diets were formulated using AMEn and digestible AA values determined from Objective 1.

In Experiment 1, AMEn was determined as 1,975, 2,644 and 3,137kcal per kg for low-oil DDGS (L-DDGS), medium-oil DDGS (M-DDGS) and high-oil DDGS (H-DDGS), respectively.

In Experiment 2, apparent amino acid digestibility was determined feeding either L-DDGS, M-DDGS or H-DDGS.

Apparent amino acid digestibility coefficients were negatively affected by oil extraction for methionine, lysine, threonine, tryptophan and arginine. Conversely, no differences in apparent amino acid digestibility coefficients were seen for isoleucine, leucine and valine.

These results indicated that L-DDGS had lower apparent amino acid coefficients for methionine, lysine, threonine, tryptophan and arginine than H-DDGS and that this should be considered when formulating diets using deoiled DDGS.

In Experiment 3, diets were formulated to contain L-DDGS, M-DDGS and H-DDGS at moderate (5, 7 and 9 per cent) and high (8, 10 and 12 per cent) inclusion rates of DDGS and fed to male broilers from one to 35 days of age.

Broilers receiving diets with a higher inclusion of DDGS had lower bodyweight gains and poorer feed conversion ratios. Oil content of the DDGS source did not affect live performance. Abdominal fat yield was reduced and breast yield was increased for broilers receiving the H-DDGS source at moderate inclusion levels.

In Experiment 4, diets were formulated to contain L-DDGS, M-DDGS and H-DDGS at moderate (5, 7, 9 and 11 per cent) and high (8, 10, 12 and 14 per cent) inclusion rates of DDGS and fed to male broilers from one to 49 days of age.

Neither DDGS source or inclusion rate affected cumulative performance nor parts yield.

In general, Dozier and Hess concluded, the data indicate acceptable performance can be obtained with deoiled DDGS if diets are formulated to the actual nutrient values of DDGS.

Using an L-DDGS source can provide adequate performance but may increase diet cost because of its lower energy contribution, the Auburn authors added.

January 2015