Dietary supplementation with fermented moringa oleifera leaves inhibits the lipogenesis in the liver of meat ducks

The aim of this study was to compare the effects of Aspergillus niger-fermented-Moringa oleifera Lam. leaves (FMOL) and non-fermented leaf (NMOL) supplementation on growth performance, carcass quality, fat deposition, and lipometabolism for ducks. A total of 450 d-old Pekin ducks were randomly allocated into 5 dietary treatments, which were then denoted as the control group (CON, basal diet), and the NMOL group (containing 0.50% MOL in the diets), FMOL1, FMOL2 and FMOL3 groups (containing 0.25%, 0.50% and 0.75% FMOL in the diets, respectively). The results showed that, as compared with the CON, body weight gain was higher in the FMOL1 and FMOL2 groups in the period of wk 1-3, wk 4-6 and the overall period of wk 1-6, whereas feed to gain was lower in the period of wk 4-6. The dressing percentage was lower in the group FMOL3 than that of in the CON. Birds in NMOL and FMOLs had lower levels of abdominal fat and subcutaneous fat than that of the CON. The contents of hepatic lipid and triglyceride (TG) in the FMOLs groups, as well as the total cholesterol (TC) in FMOL2 and FMOL3 groups were decreased as compared with the CON or NMOL. Decreased serum TG, TC, low-density lipoprotein cholesterol and increased high-density lipoprotein cholesterol and leptin was observed in the FMOL2 and FMOL3 groups as compared with the other groups. Birds fed with FMOL2 and FMOL3 had higher serum insulin, as well as leptin-receptor transcriptional expression in comparison with the CON. Furthermore, the expression levels of lipogenesis related genes (fatty acid synthase, acetylCoA carboxylase, sterol-regulatory element-binding protein-1 in liver and peroxisome proliferator-activated receptor-y) in abdominal fat were down-regulated as compared with the CON. Our results revealed that dietary 0.50% to 0.75% FMOLs alleviate body fat deposition and decease serum and hepatic lipid levels in meat ducks by suppressing lipogenesis related genes expression.