Soybean meal (SBM) provides a balanced branched-chain amino acid (BCAA) profile, whereas corn distillers’ dried grains with solubles (cDDGS) exhibit elevated Leu:Ile and Leu:Val ratios (>2.6; 15–20 points), potentially inducing BCAA antagonism in layers. This study investigated the effects of SBM and graded cDDGS inclusion levels on performance, egg quality, egg solids, and nutrient digestibility were evaluated in Hy-Line W-36 hens (27 to 47 wk of age). A total of 560 hens were randomly assigned to seven diets (20 replicates/treatment) in a randomized complete block design: T1 = corn-SBM (Met + Lys); T2 = corn-SBM (Met Lys + Thr); T3 = corn-SBM (Met + Lys + Thr + Val); T4 = corn- SBM + 7.5% cDDGS (Met, Lys, Thr, Val, Ile); T5 = corn-SBM + 15% cDDGS (Met, Lys, Thr, Val, Arg, Trp); T6 = corn-SBM + 22.5% cDDGS (Met, Lys, Thr, Val, Arg, Ile, Trp); T7 = corn-SBM + 30% cDDGS (Met, Lys, Thr, Val, Arg, Ile, Trp). Data were analyzed as a one-way ANOVA using the GLM procedure of SAS 9.4. Hens were housed in A-frame cages at industry-standard density and provided ad libitum feed. Performance was recorded daily and weekly; ileal digesta and excreta were collected for digestibility analysis at trial end. Hen-day egg production was highest in control diets and declined with increasing cDDGS, lowest in (T1–T3= 91%; T7 = 78%; P < 0.0001). Feed intake (g/b/d) and FCR (lb/doz) were highest in T3 (125.82 g; 3.64, respectively, both P < 0.0001) and lowest in T7 (101.63 g; 3.54, respectively, both P < 0.0001). Egg weight (62.36 g; P < 0.0001) and eggshell weight were highest in T3 (5.99 g; P = 0.0007). Apparent ileal digestibility of nitrogen and crude protein improved in T2–T4 (74.94%, 75.90%, 75.28% respectively; P = 0.003). These findings indicate that moderate inclusion of cDDGS (≤7.5– 15%) with crystalline amino acid supplementation in SBM-based diets supported optimal egg production and N and CP utilization, whereas higher inclusions (22.5 and 30%) reduced feed efficiency and egg production. Despite higher inclusion of crystalline amino acids in the high-cDDGS diets, optimal performance parameters were not achieved.

Domer, R., J. Gillum and P. Adhikari. 2026. Comparative effects of soybean meal and corn distillers dried grains–based diets on amino acid digestibility, performance, and egg quality in laying hens. 2026 International Poultry Scientific Forum, abstract 255P.