Abstract

The supplementation of dietary limiting amino acids (AA) with crystalline AA makes the use of low-protein diets an option in poultry production. The differing absorption rates of crystalline and protein-bound AA may lead to temporally imbalanced AA in the postabsorptive period. In this study, two experiments were conducted to evaluate the effect of encapsulated L-lysine-HCl (L-Lys-HCl) and DL-methionine (DL-Met) on the laying performance of hens. In exp. 1, a total of 135 forty-seven-wk-old Hy-Line Brown hens were subjected to three dietary treatments for 8 wk: basal diet supplemented with 0.14% L-Lys-HCl and 0.17% DL-Met to satisfy the NRC (1994) total Lys and Met recommendation (control) and basal diet supplemented with encapsulated L-Lys-HCl and DL-Met at the levels of 60% (60CLM, 0.084% L-Lys-HCl and 0.102% DL-Met) or 80% of control (80CLM, 0.112% L-Lys-HCl and 0.136% DL-Met), respectively. In exp. 2, 24 fifty-five-wk-old Hy-Line Brown hens were individually reared in cages and subjected to the same treatments as in exp. 1. The plasma concentrations of free AA and nitrogen metabolites were measured 2, 4, and 6 h after fed. The results showed that dietary AA treatment had no significant influence on body weight (BW), feed intake, laying rate, egg weight, egg mass, or feed efficiency. The expression levels of AA transporters CAT-1, y⁺LAT1, b^0,+AT, B⁰AT, rBAT, EAAT3, and PepT1 in the duodenum, jejunum, and ileum were not influenced (P > 0.05) by dietary treatment. There was an interaction of dietary AA treatment and time (P < 0.05) and the 80CLM hens exhibited higher concentrations of Lys (P < 0.05) than the controls at 2-h time point. In contrast, plasma Met concentration was not influenced (P > 0.05), while Cys was reduced in the 60CLM hens at every time point. The 80CLM hens had higher taurine concentrations than those receiving the control diet at every postprandial time point. In conclusion, these findings demonstrate that by using encapsulated form, the supplemental levels of synthetic L-Lys-HCl and DL-Met can be effectively reduced by approximately 20% with no negative effect on laying performance. The result suggests that encapsulated Lys and Met may ameliorate the postabsorptive AA balance and contribute to the reduced dietary AA supplemental levels.

中文翻译：

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使用胶囊化的 L-赖氨酸-HCl 和 DL-蛋氨酸可改善蛋鸡的餐后氨基酸平衡。

 抽象的

用结晶 AA 补充日粮限制氨基酸 ( AA ) 使得使用低蛋白日粮成为家禽生产中的一种选择。晶体和蛋白质结合 AA 的不同吸收率可能导致吸收后阶段 AA 暂时不平衡。本研究进行了两项实验来评估胶囊化 L-赖氨酸-HCl ( L-Lys-HCl ) 和 DL-蛋氨酸 ( DL-Met ) 对母鸡产蛋性能的影响。在实验中。如图 1 所示，总共 135 只 47 周龄海兰褐母鸡接受了 8 周的三种日粮处理：基础日粮添加 0.14% L-Lys-HCl 和 0.17% DL-Met 以满足 NRC（ 1994) 总赖氨酸和蛋氨酸推荐值（对照）和基础日粮中添加 60% 水平的胶囊化 L-Lys-HCl 和 DL-Met（ 60CLM 、0.084% L-Lys-HCl 和 0.102% DL-Met）或 80分别为对照百分比（ 80CLM 、0.112% L-Lys-HCl 和 0.136% DL-Met）。在实验中。 2、将 24 只 55 周龄的海兰布朗母鸡单独饲养在笼子中，并进行与实验 2 中相同的处理。 1. 喂食后2、4、6小时测定血浆游离AA和氮代谢物浓度。结果表明，日粮 AA 处理对体重 ( BW )、采食量、产蛋率、蛋重、蛋质量或饲料效率没有显着影响。 十二指肠、空肠和回肠中 AA 转运蛋白CAT-1 、 y ⁺ LAT1 、 b ^0,+ AT 、 B ⁰ AT 、 rBAT 、 EAAT3和PepT1的表达水平不受饮食治疗的影响 ( P > 0.05) 。日粮 AA 处理和时间存在交互作用 ( P < 0.05)，80CLM 母鸡在 2 小时时间点表现出比对照更高的 Lys 浓度 ( P < 0.05)。相比之下，60CLM 母鸡的血浆 Met 浓度未受影响（ P > 0.05），而 Cys 在每个时间点均降低。 80CLM 母鸡在餐后每个时间点的牛磺酸浓度都高于接受对照饮食的母鸡。总之，这些研究结果表明，通过使用胶囊形式，合成 L-Lys-HCl 和 DL-Met 的补充水平可有效降低约 20%，且对产蛋性能没有负面影响。结果表明，胶囊化的赖氨酸和蛋氨酸可以改善吸收后 AA 平衡，并有助于降低膳食 AA 补充水平。