Department of Animal Science, Shandong Agricultural University, Shandong Key Lab for Animal Biotechnology and Disease Control and Prevention, Taian City, Shandong Province, 271018, China.
Department of Animal Science, Shandong Agricultural University, Shandong Key Lab for Animal Biotechnology and Disease Control and Prevention, Taian City, Shandong Province, 271018, China.
Poult Sci. 2020 Dec;99(12):6914-6924. doi: 10.1016/j.psj.2020.09.023. Epub 2020 Sep 19.
Crystalline amino acids (AAs) exhibit high nutritional values when supplemented AA-deficient diets. However, the AAs in crystalline form in the diet are absorbed quickly than protein-bound AAs, which may take an effect on AA utilization efficiency. In this study, 2 experiments were conducted to investigate the effect of encapsulated lysine-HCl (Lys) and DL-methionine (DL-Met) on the growth performance of broiler chickens. In experiment 1, a total of 432 one-day-old male Arbor Acres broilers were subjected to 3 dietary treatments (27 pens; 16 birds per pen) for 42 d. The control group was basal diets supplemented with crystalline Lys and DL-Met, and treatment groups had basal diets supplemented with encapsulated Lys and DL-Met at the levels of 80% and 60% of control diets (80CLM, 60CLM), respectively. The growth performance, intestinal development, and transcription of AA transporters were determined. In experiment 2, 24 broiler chickens were subjected to the same treatments as in experiment 1. The plasma concentrations of free AAs were measured 0, 2, 4, and 6 h after feeding. The results showed that 80CLM treatment had no significant influence on production performance, carcass characteristics, and plasma free AAs content during the experiment compared with the control group (P > 0.05). In addition, the 80CLM group moderately enhanced gut morphology development and increased AAs' absorption capacity. However, broilers fed the 60CLM diet had lower production performance and breast muscle weight than the control group (P < 0.05), but increased villi height and BAT mRNA expression level (P < 0.05). At h 4 after feeding, the 60CLM broilers exhibited higher concentration of Ala, Cys, and total dispensable AAs than the control group (P < 0.05). In conclusion, the result suggests that the supplemental levels of crystalline Lys and DL-Met can be effectively saved approximately for 20% by using the encapsulated form in broilers, with improvements to AAs utilization efficiency, while posing no detrimental effects on production performance. Encapsulated Lys and DL-Met would have greater potential for application when replacing crystalline AAs in broiler chickens.
结晶氨基酸（AA）在补充 AA 缺乏的饮食时具有很高的营养价值。然而，饮食中以结晶形式存在的 AA 比与蛋白质结合的 AA 吸收更快，这可能会对 AA 利用效率产生影响。在这项研究中，进行了两项实验来研究包被赖氨酸-HCl（Lys）和 DL-蛋氨酸（DL-Met）对肉鸡生长性能的影响。在实验 1 中，共有 432 只 1 日龄雄性 Arbor Acres 肉鸡接受 3 种饮食处理（27 个笼子；每个笼子 16 只）42 天。对照组为基础日粮补充结晶 Lys 和 DL-Met，处理组为基础日粮补充包被 Lys 和 DL-Met，分别为对照日粮的 80%和 60%（80CLM，60CLM）。测定生长性能、肠道发育和 AA 转运体的转录。在实验 2 中，24 只肉鸡接受与实验 1 相同的处理。在喂养后 0、2、4 和 6 h 测量血浆游离氨基酸浓度。结果表明，与对照组相比，80CLM 处理在实验期间对生产性能、胴体特性和血浆游离氨基酸含量没有显著影响（P>0.05）。此外，80CLM 组适度增强了肠道形态发育并增加了 AA 的吸收能力。然而，饲喂 60CLM 日粮的肉鸡的生产性能和胸肌重量低于对照组（P<0.05），但增加了绒毛高度和 BAT mRNA 表达水平（P<0.05）。在喂养后 4 h，60CLM 肉鸡的 Ala、Cys 和总可利用氨基酸的浓度高于对照组（P<0.05）。综上所述，结果表明，在肉鸡中使用包被形式可以有效节省约 20%的结晶 Lys 和 DL-Met 的补充水平，同时提高 AA 利用效率，而对生产性能没有不利影响。包被 Lys 和 DL-Met 在替代肉鸡中的结晶 AA 时具有更大的应用潜力。
