Izadi Elham, Shahir Mohammad Hossein, Torshizi Mohammad Amir Karimi
Department of Animal Science, Faculty of Agriculture, University of Zanjan, P.O. Box: 45371-38791, Zanjan, Iran; Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
Department of Animal Science, Faculty of Agriculture, University of Zanjan, P.O. Box: 45371-38791, Zanjan, Iran.
Poult Sci. 2024 Dec;103(12):104311. doi: 10.1016/j.psj.2024.104311. Epub 2024 Sep 7.
Two separate studies were conducted in growing broiler chickens to examine the relative bioavailability (RBA) of L-smethionine (L-Met) vs. DL-methionine (DL-Met) in the starter (0-10 d, Experiment 1) and grower (11-24 d, Experiment 2) periods. In each experiment, 540 male Arian broilers were weighed and randomly allocated to nine dietary treatments in a completely randomized design with 6 replicates: basal diet (BD) with no methionine (Met) supplementation and eight diets supplemented with incremental levels (0.8, 1.6, 2.4, and 3.2 g/kg) of DL-methionine (DL-Met) or L-methionine (L-Met). Supplementation of the BD with either DL-Met or L-Met improved growth performance (P < 0.05), breast percentage (P < 0.05), and antioxidant status (P < 0.05) of broilers in both experiments. Orthogonal contrasts showed that L-Met supplementation compared to DL-Met (specifically at levels 0.8 and 1.6 g/kg) improved average daily gain (ADG, P < 0.05), average daily feed intake (ADFI, P < 0.01), and feed to gain ratio (F:G, P < 0.01) in the starter phase. In the grower phase, L-Met supplementation (specifically at levels 0.8 and 1.6 g/kg) only improved F:G (P < 0.05) compared to DL-Met, with no significant differences in the other performance parameters. Nonlinear regression analysis showed that RBA of L-Met based on carcass percentage was significantly (P < 0.05) higher than that of DL-Met in the starter phase. Based on the findings of this study, it seems that using L-Met compared to DL-Met may improve the feed efficiency and carcass percentage of young growing broiler chickens.
进行了两项独立研究，以检测L-蛋氨酸（L-Met）与DL-蛋氨酸（DL-Met）在肉仔鸡育雏期（0至10日龄，实验1）和生长期（11至24日龄，实验2）的相对生物利用率（RBA）。在每项实验中，540只雄性艾维茵肉仔鸡称重后，按照完全随机设计被随机分配到9种日粮处理组，每组6个重复：不添加蛋氨酸（Met）的基础日粮（BD）以及8种分别添加递增水平（0.8、1.6、2.4和3.2 g/kg）DL-蛋氨酸（DL-Met）或L-蛋氨酸（L-Met）的日粮。在两项实验中，用DL-Met或L-Met补充BD均改善了肉仔鸡的生长性能（P < 0.05）、胸肌率（P < 0.05）和抗氧化状态（P < 0.05）。正交对比表明，与DL-Met相比（特别是在0.8和1.6 g/kg水平），在育雏期补充L-Met提高了平均日增重（ADG，P < 0.05）、平均日采食量（ADFI，P < 0.01）和料重比（F:G，P < 0.01）。在生长期，与DL-Met相比，补充L-Met（特别是在0.8和1.6 g/kg水平）仅改善了料重比（P < 0.05），其他性能参数无显著差异。非线性回归分析表明，在育雏期，基于胴体率的L-Met的RBA显著高于DL-Met（P < 0.05）。基于本研究结果，与DL-Met相比，使用L-Met似乎可以提高幼龄生长肉仔鸡的饲料效率和胴体率。
