High-protein Distillers Research Articles

Nutritional evaluation of four co-product feedstuffs from the motor fuel ethanol distillation industry in the Midwestern USA

The objective was to determine the nutrient profile, and variability, as well as estimate the net energy (NE) of four co-product feeds of the corn grain-based motor fuel ethanol distillation industry in the Midwestern USA. Ten samples each of conventional distillers dried grains with solubles (DDGS), raw-starch ( i.e., uncooked) distillers dried grains with solubles (DDGS-BPX), high protein distillers dried grains (DDG-HP) and dehydrated dry milled corn germ (DCG) were collected over 3-week periods from production facilities in the Midwestern USA. Samples were analyzed for several organic and inorganic nutrients and were also incubated in vitro for 30 h with rumen fluid to determine the fermentability of neutral detergent fibre (aNDFom), which was used in addition to some of the organic components to estimate the NE value of the co-products. There was very little difference in the nutrient levels of the conventional DDGS versus the uncooked DDGS-BPX, with both having moderate levels of CP (∼280 g/kg DM) with relatively low buffer solubility and acid detergent insolubility. The aNDFom of both was highly fermentable (∼0.74) at 30 h of in vitro incubation and, combined with the high EE content (∼110 g/kg DM), led to a high estimated NE. However, DDGS-BPX had somewhat more S, Na, Mn, Cu, Mo and Se, and less Zn, than the conventional DDGS. The high protein DDG-HP also had somewhat less aNDFom, although its fermentability was higher, and a much lower EE level than the DDGS and DDGS-BPX. In addition, its mineral profile differed substantially from both DDGS and DDGS-BPX. The DCG had a substantially different nutrient and mineral profile than all the DDG products, and differed to a small extent from conventionally produced corn germ (National Research Council, 2001. Nutrient Requirements of Dairy Cattle, seventh rev. ed. National Academy of Sciences, Washington, DC, USA). These ‘new generation’ corn distillers co-products have a high nutritional value for ruminants and, in general, nutrient variability was low. Considered in the context of overall ration formulation criteria, these co-products should have a high nutritive value in cattle rations.

Energy, phosphorus, and amino acid digestibility of high-protein distillers dried grains and corn germ fed to growing pigs1

Three experiments were conducted to measure energy, P, and AA digestibility in 2 novel co-products from the ethanol industry [i.e., high-protein distillers dried grains (HP DDG) and corn germ]. These products are produced by dehulling and degerming corn before it enters the fermentation process. Experiment 1 was an energy balance experiment conducted to measure DE and ME in HP DDG, corn germ, and corn. Six growing pigs (initial BW, 48.9 +/- 1.99 kg) were placed in metabolism cages and fed diets based on corn, corn and HP DDG, or corn and corn germ. Pigs were allotted to a replicated, 3 x 3 Latin square design. The DE and ME in corn (4,056 and 3,972 kcal/kg of DM, respectively) did not differ from the DE and ME in corn germ (3,979 and 3,866 kcal/kg of DM, respectively). However, HP DDG contained more (P < 0.05) energy (4,763 kcal of DE/kg of DM and 4,476 kcal of ME/kg of DM) than corn or corn germ. Experiment 2 was conducted to measure apparent total tract digestibility (ATTD) and true total tract digestibility of P in HP DDG and corn germ. Thirty growing pigs (initial BW, 33.2 +/- 7.18 kg) were placed in metabolism cages and fed a diet based on HP DDG or corn germ. A P-free diet was used to measure endogenous P losses. Pigs were assigned to treatments in a randomized complete block design, with 10 replications per treatment. The ATTD and the retention of P were calculated for the diets containing HP DDG and corn germ, and the endogenous loss of P was estimated from pigs fed the P-free diet. The ATTD was lower (P < 0.05) in corn germ (28.6%) than in the HP DDG (59.6%). The retention of P was also lower (P < 0.05) in pigs fed corn germ (26.7%) than in pigs fed HP DDG (58.9%). The endogenous loss of P was estimated to be 211 +/- 39 mg per kg of DMI. The true total tract digestibility of P for HP DDG and corn germ was calculated to be 69.3 and 33.7%, respectively. In Exp. 3, apparent ileal digestibility and standardized ileal digestibility values of CP and AA in HP DDG and corn germ were measured using 6 growing pigs (initial BW, 78.2 +/- 11.4 kg) allotted to a replicated, 3 x 3 Latin square design. The apparent ileal digestibility for CP and all AA except Arg and Pro, and the standardized ileal digestibility for CP and all AA except Arg, Lys, Gly, and Pro were greater (P < 0.05) in HP DDG than in corn germ. It was concluded that HP DDG has a greater digestibility of energy, P, and most AA than corn germ.