一次注射[^3H]Leu检测家禽内源氨基酸损失量的方法

DETERMINING ENDOGENOUS AMINO ACID LOSSES IN POULTRY USING SINGLE INJECTION OF [3H] LEUCINE

通过绝食法 (FAS)、强饲无氮饲粮法 (NFD)、NFD + 3 2 0 %酶解酪蛋白 (EHC)、以豆粕为唯一氮源的饲粮粗蛋白 (CP)水平为 5 %和 2 0 % ,以及棉粕为氮源的CP2 0 %半合成饲粮 ,证明给家禽皮下一次引入 30 μCi[3 H]Leu kg体重 (BW)后 ,48h内排泄物内源Leu放射性比活度(SRe)与相应血浆Leu放射性比活度 (SRP)之比为一恒值 ,根据此定律并依据NFD时内源氨基酸组成模式可测定采食实际饲粮时的内源氨基酸损失量 (EAAL)。

Three sets of young hens and broilers received six diet treatments. The diets were on fast (FAS), and force-fed nitrogen-free diet (NFD), NFD+3.20% enzyme hydrolysed casein (EHC), semi-synthesized diets with 5% and 20% crude protein (CP) in which soybean meal was the sole nitrogen source, and semi-synthesized diet with 20% CP in which cotton seed meal was the sole nitrogen source. After force-fed, 30μCi[ 3H]Leu/kgBW was injected subcutaneously, the excreta in the following 48h were totally collected, and venous blood samples were taken at 5 min, 30 min, 4 h, 24h, 36 h and 48h. The study showed that the ratios between specific radioactivity (SR) of endogenous Leucine in excreta (SRe) and SR of free Leucine in plasma (SRp) kept constant, no matter what kinds of diets the birds ate. This made it possible to determine endogenous amino acid losses (EAAL) of practical diets when NFD was taken as the reference.