排空-强饲法测定鸭饲料氨基酸真消化率的研究

Study on the Emptying-force-feeding Method for Measuring True Digestibility of Amino Acids in Ducks

本试验旨在通过研究"排空-强饲"条件下,鸭饲料氨基酸的排泄规律是否满足Sibbald"排空-强饲"法的基本条件,为Sibbald法是否适合于鸭饲料氨基酸真消化率的测定提供参考。试验采用单因素完全随机设计,将84只成年公鸭随机分配到7个处理中,即饥饿组和6种试验日粮组(豆粕在试验日粮中的比例分别为0、10%、20%、30%、40%、50%),每个处理4个重复,每个重复3只鸭,以"排空-强饲"法测定日粮的氨基酸排泄量。结果表明,在以豆粕为唯一氨基酸来源的日粮中,成年公鸭17种氨基酸的排泄量与摄入量间呈极显著的线性关系(P<0.01)。无氮日粮条件下内源性组氨基酸的排泄量显著地高于饥饿条件下所测值(P<0.05),而其他内源性氨基酸的排泄量在饲喂无氮日粮与饥饿条件下无显著差异。鸭氨基酸排泄量与摄入量间回归直线截距中仅精氨酸、组氨酸及甘氨酸的回归截距显著地高于饥饿法所测相应的内源性氨基酸值(P<0.05),而其他14种氨基酸的回归截距与饥饿法所测相应的内源性氨基酸无显著差异。因此,Sibbald"排空-强饲"法可以用于鸭饲料氨基酸真消化率的测定。然而,客观、准确地估测内源性氨基酸的量对"排空-强饲"法氨基酸真消化率的测定值至关重要。

The relationship between output and intake of amino acids in ducks was investigated to study the feasibility of Sib- bald＇s emptying-force-feeding method for true digestibility of amino acids determination. Eighty four male adult ducks were randomly divided into 7 treatments with 4 replicates per treatment and 12 ducks per replicate. One treatment was fasted treatment and other 6 treatments were fed with soybean meal with 6 levels in diets （0%0, 10%, 20%, 30%, 40%, and 50% respectively）. Sibbald＇s emptying-force-feeding method was used to determine the volume of amino acid output. The results showed that the significant linear relationship between amino acids output and intake was appeared in these 6 diets using soybean meal as the only protein source （P〈0.01）. The endogenous losses of 17 amino acids except His were not significantly different between the ducks fed with nitrogen-free diet and the fasted treatment （P〈0.05）. In the regression intercepts of output and intake of amino acids in ducks, only the regression intercepts of Arg, His and Gly were significantly higher than the corresponding endogenous amino acids value of fasting ducks （P〈0.05）. In conclusion, Sibbald＇s emptying-force-feeding method can be used for measuring the true digestibility of amino acids of duck feedstuff, but the accuracy of the determination of endogenous amino acids losses is important to the true digestibility of amino acids in ducks.