This experiment aimed to study the effects of supplemental methionine sources, 2-hydroxy-4 methyl(thio) butanoic acid (HMTBa) and DL-Methionine (DL-Met), on productive performance, egg quality, and redox status of laying ducks. A total of 792 healthy 25-wk-old Longyan laying ducks with similar body weights were randomly allotted to 11 treatment groups. Each treatment group had 6 replicates of 12 ducks. The trial lasted for 16 wk. Ducks were fed a basal deficient diet (Met: 0.24%; Met + Cys: 0.51%) or supplemented with DL-Met or HMTBa at 0.05%, 0.12%, 0.19%, 0.26%, and 0.33% of diet, respectively. Compared with the basal diet, supplementation with either DL-Met or HMTBa increased the average egg weight, egg mass, and decreased feed to egg ratio during the whole trial period (P < 0.05). Albumen weight and its ratio to total egg weight were increased, but yolk and shell ratio, albumen height, Haugh unit and shell breaking strength were decreased (P < 0.05). Dietary DL-Met or HMTBa supplementation increased taurine, methionine, leucine, tryptophan and arginine content, and decreased serine and lysine content in plasma (P < 0.05). The redox status of laying ducks was improved by enhancing the glutathione peroxidase and catalase activities, glutathione content and its ratio relative to glutathione (oxidized) content and decreasing malondialdehyde content and increasing mRNA expression of superoxide dismutase-1, glutathione peroxidase-1, hemeoxygenase-1 and nuclear factor-like 2 in liver and ileum with the supplementation of DL-Met or HMTBa (P < 0.05). Liver health status measured by average area proportion lipid droplet was improved with supplementation of DL-Met or HMTBa (P < 0.05). Villus height and villus height to crypt depth ratio in the ileum and the ileal gene expression of tight junction protein and occludin were increased with DL-Met or HMTBa supplementation (P < 0.05). Taken together, these results suggested that the efficacy of dietary supplementation of HMTBa was similar to DL-Met, and it ranged from 98% to 100% for productive performance and egg albumen ratio in laying ducks (25 to 41 wk).

本试验旨在研究补充蛋氨酸来源 2-羟基-4 甲基（硫代）丁酸 (HMTBa) 和 DL-蛋氨酸 (DL-Met) 对蛋鸭生产性能、蛋品质和氧化还原状态的影响。选取体重相近的25周龄健康龙岩蛋鸭792只，随机分为11个处理组。每个处理组有 6 个重复，每组 12 只鸭。审判持续了16周。鸭子饲喂基础缺乏日粮（Met：0.24%；Met + Cys：0.51%）或分别补充日粮的 0.05%、0.12%、0.19%、0.26% 和 0.33% 的 DL-Met 或 HMTBa。与基础日粮相比，在整个试验期间添加 DL-Met 或 HMTBa 均增加了平均蛋重、蛋质量，并降低了料蛋比（P < 0.05）。蛋白重量及其占蛋总重的比例增加，但蛋黄壳比、蛋白高度、哈夫单位和破壳强度降低（P  < 0.05）。膳食补充 DL-Met 或 HMTBa 增加了血浆中牛磺酸、蛋氨酸、亮氨酸、色氨酸和精​​氨酸的含量，降低了丝氨酸和赖氨酸的含量（P  < 0.05）。通过提高谷胱甘肽过氧化物酶和过氧化氢酶活性、谷胱甘肽含量及其与谷胱甘肽（氧化）含量的比值，降低丙二醛含量，增加超氧化物歧化酶-1、谷胱甘肽过氧化物酶-1、血红素加氧酶-的mRNA表达，改善蛋鸭氧化还原状态。补充 DL-Met 或 HMTBa 后肝脏和回肠中的 1 和核因子样 2 ( P < 0.05）。通过补充 DL-Met 或 HMTBa，以平均脂滴面积比例衡量的肝脏健康状况得到改善（P  < 0.05）。补充DL-Met或HMTBa可增加回肠绒毛高度、绒毛高度与隐窝深度之比以及回肠紧密连接蛋白和occludin基因表达量（P  < 0.05）。综上所述，这些结果表明，日粮补充 HMTBa 的功效与 DL-Met 相似，对产蛋鸭（25 至 41 周）的生产性能和蛋清比率的影响范围为 98% 至 100%。