Effect of feeding commercial laying hens diets containing distillers dried grains plus solubles on nutrient mass balance

The main objective of this study was to evaluate the effect of feeding laying hens diets containing 0%, 10%, or 20% corn distillers dried grains plus solubles (DDGS) on nutrient mass balance in laying hens aged 21 to 26 weeks. Hyline W36 hens (n=640) were allocated, randomly, to eight environmental rooms. Excreta that had accumulated in each room were weighed and analyzed to determine excretion of nitrogen (N), phosphorus (P), and sulfur (S) that remained in the excreta following the 5-wk study. Apparent retention of N, P, and dry matter(DM) were determined using an indigestible marker. No significant differences in DM excretion (26.83 g hen-1 d-1), N intake (2.65 g hen -1 d-1) or excretion (1.03 g hen-1 d -1), P intake (733.33 mg hen-1 d-1) or excretion (662.50 mg hen-1 d-1) were observed. However, an increase in S excretion was observed as the amount of DDGS inclusion increased from 0% to 10% to 20% (116.67, 137.50, and 195.83 mg hen-1 d -1, respectively). The results indicated apparent retentions of N, P, and DM in birds fed diets containing different DDGS were consistent across diets (57.7%, 29.5%, and 75.1%). Across diets, 39%, 27%, and 9% of consumed N was accounted for in excreta, eggs, and as gaseous losses, respectively. On average, 55%, 34%, and 0.2% of consumed S was accounted for in excreta, eggs, and as gaseous losses, respectively. Consumed P was recovered largely in excreta (90%) and to a lesser extent in eggs (9.0%). These data suggest that excreta is the primary reservoir for dietary nutrients and that losses to air emissions represents the smallest portion of consumed nutrients, relative to exports in eggs and nutrients retained in excreta. © 2013 American Society of Agricultural and Biological Engineers.