Effect of Particle Size, DDGS Inclusion, and Pellet Quality on Nutrient Digestibility, Gastrointestinal Development, and Live Performance of Broilers and Swine

Distillers dried grains with solubles (DDGS) is the co-product that remains after fermenting the starch fraction of grains to produce ethanol. Previous research studies have shown that the main limitations for using DDGS in poultry and swine diets were reduced pellet quality and increased nutrient variability. Our working hypothesis was that further grinding of DDGS would improve pellet quality and live performance in poultry and swine and that the optimum dietary inclusion would depend upon feed formulation strategies. The first study (Chapter 2) was designed to evaluate the effect of inclusion level and particle size of DDGS as well as soybean meal (SBM) particle size on pellet durability index (PDI). Diets containing DDGS exhibited improved (P≤0.05) PDI relative to diets without DDGS. Further grinding of SBM in diets with DDGS also improved (P≤0.05) PDI. Adding 30% DDGS to corn-soy diets improved PDI and further grinding of SBM, but not DDGS, improved pellet quality.;The second study (Chapter 3) evaluated the effect of particle size and DDGS inclusion on pellet quality and live performance of broilers fed diets formulated on a digestible amino acid (AA) basis. Birds fed diets with fine DDGS consumed more feed (P≤0.05) and exhibited greater BW (P≤0.05) at 42 d than birds fed diets with coarse DDGS with no difference in feed efficiency. Birds fed pelleted diets with fines removed exhibited greater BW at 35 and 42 d than birds fed pelleted diets with 50% fines. Birds fed diets containing 30% DDGS consumed more feed ( P≤0.05) but exhibited poorer feed efficiency (P≤0.05) at 42 d than birds fed 15% DDGS with no differences in BW. The results observed on this experiment demonstrated that broilers exhibited improved live performance when fed finely ground DDGS (482 mum) with no fines in the feed and that up to 30% DDGS could be fed when diets were formulated on a digestible AA basis.;The third study (Chapter 4) evaluated the effect of dietary DDGS inclusion and the method of crude fat analysis on pellet quality, nutrient digestibility, incidence of footpad lesions, and broiler live performance in diets formulated on a total AA basis. Increasing dietary inclusion of DDGS to 30% reduced pellet quality, BW, and protein digestibility as well as increased footpad lesions. Feed efficiency was also poorer. Evidently, broilers can be fed up to 15% DDGS in diets formulated on total AA basis while the method of estimating crude fat had a marginal effect on live performance.;The final experiment (Chapter 5) evaluated the effect of DDGS particle size and percentage fines on grower-finisher pig performance. Particle size of DDGS and percentage fines in the feed did not impact (P≤0.05) daily gain, daily feed intake, or feed efficiency. It was determined that the particle size of DDGS did not improve overall live performance so DDGS did not need to be further ground upon receipt at the feed mill. In addition, up to 25% pellet fines could be fed without affecting grower-finisher pig performance.;Based on the results of these 4 studies, it was concluded that: (1) further grinding DDGS did not influence pellet quality and grower-finisher pig live performance; (2) grinding SBM improved pellet quality; (3) feed containing up to 25% fines could be fed to broilers or grower-finisher pigs without adverse effects on live performance; (4) and use of digestible AA values during feed formulation allowed for higher DDGS inclusion.