College of Animal Science and Technology, Hunan Agriculture University, Changsha 410128, China.
College of Animal Science and Technology, Hunan Agriculture University, Changsha 410128, China.
Poult Sci. 2023 Jun;102(6):102638. doi: 10.1016/j.psj.2023.102638. Epub 2023 Mar 8.
This experiment was carried out to investigate the mechanism of action of mulberry leaf extract (MLE) in reducing abdominal fat accumulation in female broilers. A total of 192 one-day-old female Arbor Acres (AA) broilers were divided into 4 diet groups, with each group consisting of 8 replicates with 6 birds per replicate. The diets contained a basal diet and 3 test diets with supplementation of 400, 800, or 1,200 MLE mg/kg, respectively. The trial had 2 phases that lasted from 1 to 21 d and from 22 to 56 d, respectively. The growth performance, abdominal fat deposition, fatty acid composition, serum biochemistry and mRNA expression of genes related to fat metabolism in liver were determined. The results showed that, 1) dietary supplementation with MLE had no significant impact on broilers final body weight, average daily gain (ADG), or feed to gain ration (F/G) (P > 0.05), but linearly reduced abdominal fat accumulation in both experimental phases (P < 0.05); 2) the total contents of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), such as palmitoleic acid, oleic acid, and eicosadienoic acid, were increased quadratically as a result of dietary supplements of 400, 800, and 1,200 mg/kg MLE (P < 0.01), while the total contents of saturated fatty acids (SFA), such as teracosanoic acid were decreased (P < 0.01); 3) the addition of 800 or 1,200 MLE mg/kg to the diet linearly reduced total cholesterol (TC) in the serum and liver (P < 0.05). Adenosine-activated protein kinase (AMPK) mRNA expression in the liver was quadratically increased by the addition of 800 or 1,200 MLE mg/kg to the diet (P < 0.05), and the mRNA expression of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), and acetyl-CoA carboxylate), fatty acid synthase (FAS) were linearly decreased (P < 0.05). In conclusion, MLE can be employed as a viable fat loss feed supplement in fast-growing broiler diets since it reduces abdominal fat deposition in female AA broilers via the AMPK/SREBP-1c/ACC signaling pathway. MLE can also be utilized to modify the fatty acid profile in female broilers (AA) at varied inclusion levels.
本实验旨在研究桑叶提取物（MLE）在减少雌性肉鸡腹部脂肪积累方面的作用机制。将 192 只 1 日龄的雌性爱拔益加（AA）肉鸡分为 4 个日粮组，每个组 8 个重复，每个重复 6 只鸡。日粮包含基础日粮和 3 种试验日粮，分别补充 400、800 或 1200mg/kg MLE。试验分为 2 个阶段，分别持续 1 至 21 天和 22 至 56 天。测定生长性能、腹部脂肪沉积、脂肪酸组成、血清生化指标和与肝脏脂肪代谢相关基因的 mRNA 表达。结果表明：1）日粮中添加 MLE 对肉鸡终体重、平均日增重（ADG）或饲料增重比（F/G）没有显著影响（P>0.05），但线性降低了两个实验阶段的腹部脂肪积累（P<0.05）；2）单不饱和脂肪酸（MUFA）和多不饱和脂肪酸（PUFA）的总含量，如棕榈油酸、油酸和二十碳二烯酸，随着 400、800 和 1200mg/kg MLE 的日粮补充而呈二次增加（P<0.01），而饱和脂肪酸（SFA）的总含量，如三十烷酸则降低（P<0.01）；3）日粮中添加 800 或 1200mg/kg MLE 可线性降低血清和肝脏中的总胆固醇（TC）（P<0.05）。日粮中添加 800 或 1200mg/kg MLE 可使肝脏中腺苷激活蛋白激酶（AMPK）mRNA 表达呈二次增加（P<0.05），固醇调节元件结合蛋白-1c（SREBP-1c）、乙酰辅酶 A 羧化酶（ACC）和乙酰辅酶 A 羧化酶（FAS）的 mRNA 表达呈线性降低（P<0.05）。综上所述，MLE 可作为一种有效的肉鸡减肥饲料添加剂，通过 AMPK/SREBP-1c/ACC 信号通路减少雌性 AA 肉鸡腹部脂肪沉积。此外， MLE 还可以改变不同添加水平下雌性肉鸡（AA）的脂肪酸谱。
