Pahm A A, Scherer C S, Pettigrew J E, Baker D H, Parsons C M, Stein H H
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
Poult Sci. 2009 Mar;88(3):571-8. doi: 10.3382/ps.2008-00184.
This study was conducted to compare the concentration of standardized digestible (SDD) Lys and relative bioavailable Lys in 7 sources of corn distillers dried grains with solubles (DDGS). A second objective was to evaluate 2 in vitro methods, reactive Lys and color score, to predict the concentration of SDD Lys and bioavailable Lys in DDGS. Seven sources of DDGS were fed to cecectomized roosters, and digestibility of amino acids was measured using the total excreta collection method. To measure the relative bioavailable Lys in DDGS, a standard curve (r(2) = 0.96, P < 0.01) was constructed from 9-d weight gain of young chicks fed a Lys-deficient basal diet or diets containing increasing concentrations of l-Lys-HCl. Seven additional diets were formulated by adding each of the 7 sources of DDGS to the basal diet, and total weight gain of chicks was measured. Weight gain of chicks fed each DDGS-containing diet was then compared with the standard curve to calculate the bioavailable Lys and bioavailability of Lys in each source of DDGS. All DDGS sources were analyzed for reactive Lys using the guanidination procedure, and a Hunterlab color score was used to measure the degree of lightness (L), redness (a), and yellowness (b). Results showed that the mean SDD Lys values and the mean relative bioavailability of Lys were 61.4 and 69.0%, respectively. Differences between the concentration of SDD Lys and the concentration of bio-available Lys were not observed in 5 of 7 sources of DDGS. The concentration of SDD Lys was correlated (r(2) = 0.84, P < 0.05) with the concentration of reactive Lys in DDGS. Greater Hunterlab L scores were associated with a greater (r(2) = 0.90, P < 0.05) concentration of bioavailable Lys in DDGS. In conclusion, the concentration of SDD Lys in DDGS does not overestimate the concentration of bioavailable Lys for poultry. Values for reactive Lys may be used to estimate the concentration of SDD Lys, whereas Hunterlab L may be used to estimate the concentration of bioavailable Lys in DDGS.
本研究旨在比较7种玉米干酒糟及其可溶物（DDGS）来源中标准化可消化（SDD）赖氨酸和相对生物可利用赖氨酸的浓度。第二个目标是评估两种体外方法，即反应性赖氨酸和颜色评分，以预测DDGS中SDD赖氨酸和生物可利用赖氨酸的浓度。将7种DDGS来源喂给切除盲肠的公鸡，并使用全排泄物收集法测量氨基酸的消化率。为了测量DDGS中相对生物可利用赖氨酸，根据饲喂低赖氨酸基础日粮或含有递增浓度L-赖氨酸盐酸盐日粮的幼雏9天体重增加情况构建了标准曲线（r² = 0.96，P < 0.01）。另外通过将7种DDGS来源分别添加到基础日粮中来配制7种日粮，并测量雏鸡总增重。然后将饲喂每种含DDGS日粮的雏鸡增重与标准曲线进行比较，以计算每种DDGS来源中生物可利用赖氨酸的含量和赖氨酸的生物利用率。使用胍基化程序分析所有DDGS来源的反应性赖氨酸，并使用Hunterlab颜色评分来测量亮度（L）、红色度（a）和黄色度（b）。结果表明，SDD赖氨酸的平均含量和赖氨酸的平均相对生物利用率分别为61.4%和69.0%。在7种DDGS来源中的5种中未观察到SDD赖氨酸浓度与生物可利用赖氨酸浓度之间的差异。DDGS中SDD赖氨酸浓度与反应性赖氨酸浓度相关（r² = 0.84，P < 0.05）。较高的Hunterlab L评分与DDGS中较高的生物可利用赖氨酸浓度相关（r² = 0.90，P < 0.05）。总之，DDGS中SDD赖氨酸浓度不会高估家禽生物可利用赖氨酸的浓度。反应性赖氨酸的值可用于估计SDD赖氨酸的浓度，而Hunterlab L可用于估计DDGS中生物可利用赖氨酸的浓度。
