Utilization of Energy and Amino Acids of Spray-Dried Egg, Plasma Protein, and Soybean Meal by Ducks

A study was conducted to determine AME n , TME n , apparent amino acid digestibility (AAAD), and true amino acid digestibility (TAAD) of spray-dried egg (SDE), plasma protein (PP), and soybean meal (SBM). AME n and TME n values for ducks fed SDE were higher (P ≤ 0.001) than for ducks fed PP, which were higher than SBM. The AME n values were 5.048, 3.230, and 2.605 kcal/ g for SDE, PP, and SBM, respectively, with TME n values of 5.373,3.555, and 2.930 kcal/g, respectively. Spray-dried egg, PP, and SBM were similar in apparent digestibility of the indispensable amino acids except for methionine, histidine, and valine. Apparent methionine digestibility in SDE (95.5%) was higher (P ≤ 0.01) than PP (88.3%) or SBM (91.3%). Apparent digestibilities of dispensable amino acids were similar for SDE, PP, and SBM except proline and alanine. Apparent alanine digestibility in SDE (89.9%) was higher (P ≤ 0.05) than in SBM (85.7%). True digestibilities of indispensable amino acids were similar in SDE, PP, and SBM except for methionine, histidine, and valine. True methionine digestibility was higher (P ≤ 0.05) for SDE (97.0%) than for PP (89.8%) or SBM (92.7%), with PP and SBM being similar. True histidine and valine digestibilities were significantly lower for SDE (P ≤ 0.05) than for PP or SBM. True digestibilities of the dispensable amino acids were also similar in SDE, PP, and SBM except for proline and alanine. This study demonstrates that the energy value of SDE is greater than that of PP or SBM.