Hong D, Ragland D, Adeola O
Department of Animal Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
Poult Sci. 2001 Nov;80(11):1600-6. doi: 10.1093/ps/80.11.1600.
An experiment was conducted using the TMEn bioassay method to investigate the additivity and associative effects of metabolizable energy and amino acid digestibility in barley and canola meal for White Pekin ducks. Additivity was tested by comparing the difference between observed values determined in a complete diet and predicted values from measurements determined with individual ingredients (barley and canola meal). Six ducks each were assigned to diets of barley, canola meal, the complete diet, and dextrose. Dextrose-fed ducks were used for estimation of endogenous losses for calculation of true amino acid digestibility. The observed AME, TME, AMEn, and TMEn values in the complete diet were 0.065, 0.083, 0.016, and 0.023 (kcal/g), respectively, numerically higher than predicted values. Differences between observed and predicted values were not significant (P > 0.05), indicating that the AME, AMEn, TME, and TMEn in barley and canola meal were all additive. In general, observed values for apparent amino acid digestibility (AAAD) and true amino acid digestibility (TAAD) in the complete diet were higher than those predicted from individual ingredients. Observed AAAD for lysine, histidine, tryptophan, alanine, and aspartate were higher (P < 0.05) than predicted values, indicating that digestibilities of these amino acids were not additive. The mean of AAAD in canola meal (77.29%) was higher (P < 0.05) than the observed values of barley (52.2%) and complete diet (64.55%). For TAAD values, differences between observed and predicted values were significant for lysine, histidine, and tryptophan (P < 0.05). The mean of TAAD in canola meal, barley, and complete diet were 85.88, 80.87, and 81.33%, respectively. The average difference between observed and predicted values for TAAD (1.18 %) was smaller than that of AAAD (5.41%). These results indicated that ME values for barley and canola meal were additive in the complete diet but that digestibilities of some amino acids were not additive; they further suggested that there were some associative effects of amino acids in barley and canola meal for ducks.
采用TMEn生物测定法进行了一项实验，以研究大麦和油菜籽粕中可代谢能量和氨基酸消化率对北京鸭的加性效应和协同效应。通过比较在全价日粮中测定的观测值与用单一饲料原料（大麦和油菜籽粕）测定值预测的数值之间的差异来检验加性效应。每组6只鸭，分别饲喂大麦、油菜籽粕、全价日粮和葡萄糖。以饲喂葡萄糖的鸭来估计内源损失，用于计算真氨基酸消化率。全价日粮中观测到的AME、TME、AMEn和TMEn值分别为0.065、0.083、0.016和0.023（千卡/克），数值上高于预测值。观测值与预测值之间的差异不显著（P>0.05），表明大麦和油菜籽粕中的AME、AMEn、TME和TMEn均具有加性效应。总体而言，全价日粮中表观氨基酸消化率（AAAD）和真氨基酸消化率（TAAD）的观测值高于单一饲料原料预测值。赖氨酸、组氨酸、色氨酸、丙氨酸和天冬氨酸的观测AAAD高于（P<0.05）预测值，表明这些氨基酸的消化率不具有加性效应。油菜籽粕中AAAD的平均值（77.29%）高于（P<0.05）大麦（52.2%）和全价日粮（64.55%）的观测值。对于TAAD值，赖氨酸、组氨酸和色氨酸的观测值与预测值之间差异显著（P<0.05）。油菜籽粕、大麦和全价日粮中TAAD的平均值分别为85.88%、80.87%和81.33%。TAAD观测值与预测值的平均差异（1.18%）小于AAAD（5.41%）。这些结果表明，在全价日粮中大麦和油菜籽粕的ME值具有加性效应，但一些氨基酸的消化率不具有加性效应；进一步表明大麦和油菜籽粕中氨基酸对鸭存在一些协同效应。
