Department of Animal Science.
Department of Animal Science, North Carolina State University, Raleigh 27695.
Poult Sci. 2018 Jan 1;97(1):102-109. doi: 10.3382/ps/pex259.
This study was conducted to test the effects of dietary supplementation of feed grade L-Met on growth performance and redox status of turkey poults compared with the use of conventional DL-Met. Three hundred and eighty five newly hatched turkey poults were weighed and allotted to 5 treatments in a completely randomized design and the birds were fed dietary treatments for 28 d, including a basal diet (BD), the BD + 0.17 or 0.33% DL-Met or L-Met (representing 60, 75, and 90% of the requirement by National Research Council (NRC) for S containing AA, respectively). Increasing Met supplementation from 0 to 0.33% increased (P < 0.05) weight gain (690 to 746 g) and feed intake (1,123 to 1,248 g) of turkey poults. Supplementing L-Met tended (P = 0.053) to reduce feed to gain ratio (1.70 to 1.63) compared with DL-Met. The relative bioavailability of L-Met to DL-Met was 160% based on a multilinear regression analysis of weight gain. Supplementing Met regardless of its sources decreased (P < 0.05) malondialdehyde (3.29 to 2.47 nmol/mg protein) in duodenal mucosa compared with birds in the BD. Supplementing L-Met tended (P = 0.094) to decrease malondialdehyde (1.27 to 1.16 nmol/mg protein) and increase glutathione (3.21 to 3.45 nmol/mg protein) in the liver compared with DL-Met. Total antioxidant capacity, protein carbonyl, and morphology of duodenum and jejunum were not affected by Met sources. In conclusion, dietary supplementation of 0.33% Met to a diet with S containing AA meeting 60% of the NRC requirement enhanced weight gain, feed intake, and redox status by reducing oxidative stress in the gut and liver of turkey poults during the first 28 d of age. Use of L-Met tended to enhance feed efficiency and was more effective in reducing oxidative stress and increasing glutathione in the liver compared with the use of DL-Met. The use of L-Met as a source of Met replacing DL-Met seems to be beneficial to turkey poults during the first 28 d of age.
本研究旨在测试饲粮添加饲料级 L-蛋氨酸（L-Met）对火鸡雏生长性能和氧化还原状态的影响，与使用常规 DL-蛋氨酸（DL-Met）相比。385 只刚出壳的火鸡雏称重后，完全随机设计分为 5 个处理组，每组 77 只，饲养 28 d，基础日粮（BD），BD+0.17%或 0.33%DL-Met 或 L-Met（分别代表美国国家研究委员会（NRC）对含硫必需氨基酸（S-AA）需求的 60%、75%和 90%）。从 0 增加到 0.33%Met 补充量增加了火鸡雏的体重增加（690 至 746g）和采食量（1123 至 1248g）（P<0.05）。与 DL-Met 相比，补充 L-Met （P=0.053）可降低饲料增重比（1.70 至 1.63）。根据体重增长的多元线性回归分析，L-Met 对 DL-Met 的相对生物利用率为 160%。无论其来源如何，补充 Met 都会降低十二指肠黏膜中的丙二醛（3.29 至 2.47nmol/mg 蛋白）（P<0.05）。与 DL-Met 相比，补充 L-Met 可降低肝脏中的丙二醛（1.27 至 1.16nmol/mg 蛋白）和增加谷胱甘肽（3.21 至 3.45nmol/mg 蛋白）（P=0.094）。十二指肠和空肠的总抗氧化能力、蛋白质羰基和形态不受 Met 来源的影响。总之，在满足 NRC 60%S-AA 需求的含 S-AA 日粮中添加 0.33%Met，可通过减少雏鸡肠道和肝脏的氧化应激来提高生长性能、采食量和氧化还原状态。与使用 DL-Met 相比，使用 L-Met 作为 Met 的来源来替代 DL-Met，在提高饲料效率和降低肝脏氧化应激及增加谷胱甘肽方面更有效。在火鸡雏 28 日龄内，使用 L-Met 作为 Met 的来源似乎对其有益。
