College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Sci Rep. 2017 May 15;7(1):1924. doi: 10.1038/s41598-017-02142-z.
This study investigated the responses of fast- (FG) and slow- (SG) growing broilers to dietary methionine (Met) status. The broilers were subjected to low (LM, 0.38 and 0.28 g/100 g), adequate (AM, 0.51 and 0.42 g/100 g) and high (HM, 0.65 and 0.52 g/100 g) Met during 1-21 and 22-42 d, respectively. Compared with the LM diets, the AM and HM diets increased body weight gain only in the FG broilers. The HM diets increased breast muscle yield only in the FG broilers, although insulin-like growth factor-I (IGF-I) concentration was increased in both strains of broilers. The HM diets increased mRNA levels of myogenic regulatory factors (MRF4, Myf5) and myocyte enhancer factor 2 (MEF2A and MEF2B) in the FG broilers, and increased MEF2A and decreased myostatin mRNA level in the SG broilers. Extracellular signal-regulated kinase (ERK) phosphorylation of breast muscle was increased by the HM diets in both strains of broilers, but mechanistic target of rapamycin (mTOR) phosphorylation was increased by the AM and HM diets only in the FG broilers. These results reflect a strain difference in broiler growth and underlying mechanism in response to dietary Met.
本研究旨在探讨快速（FG）和慢速（SG）生长肉鸡对饲粮蛋氨酸（Met）状况的反应。肉鸡分别在 1-21 日龄和 22-42 日龄接受低（LM，0.38 和 0.28 g/100 g）、适（AM，0.51 和 0.42 g/100 g）和高（HM，0.65 和 0.52 g/100 g）Met 饲粮。与 LM 饲粮相比，AM 和 HM 饲粮仅增加了 FG 肉鸡的体重增重。HM 饲粮仅增加了 FG 肉鸡的胸肌产率，尽管两种肉鸡的胰岛素样生长因子-I（IGF-I）浓度都增加了。HM 饲粮增加了 FG 肉鸡的成肌调节因子（MRF4、Myf5）和肌细胞增强因子 2（MEF2A 和 MEF2B）的 mRNA 水平，并增加了 SG 肉鸡的 MEF2A 和减少了肌肉生长抑制素 mRNA 水平。HM 饲粮增加了两种肉鸡的胸肌细胞外信号调节激酶（ERK）磷酸化，但 AM 和 HM 饲粮仅在 FG 肉鸡中增加了机械性靶标雷帕霉素（mTOR）磷酸化。这些结果反映了肉鸡生长对饲粮 Met 的反应存在品种差异及其潜在机制。
