Influences of five dietary manganese sources on growth, feed utilization, lipid metabolism, antioxidant capacity, inflammatory response and endoplasmic reticulum stress in yellow catfish intestine

The present study was conducted to evaluate the influences of five dietary manganese (Mn) sources on growth, feed utilization, lipid metabolism, antioxidant capacity, inflammatory response and endoplasmic reticulum stress in intestinal tissues of yellow catfish Pelteobagrus fulvidraco. Five Mn sources include Mn sulfate monohydrate (MnSO4·H2O), Mn dioxide (MnO2), Mn dioxide nanoparticles (MnO2NPs), Mn glycine chelate (Mn-Gly) and hydroxymethionine-chelated Mn (Mn-MHA). Yellow catfish (initial body weight: 2.69 ± 0.01 g/fish) were fed five experimental diets for 10 weeks. Dietary Mn sources significantly affected intestinal Mn content and metabolism. Compared to other Mn sources, yellow catfish fed organic Mn sources (Mn-Gly and Mn-MHA) tended to improve growth, feed utilization, intestinal histology, up-regulated mRNA abundance of tight junction-relevant genes, increased intestinal fatty acid uptake and transport and triglyceride deposition, and reduced inflammatory responses. These dietary organic Mn supplements also increased intestinal antioxidant capacity by up-regulating antioxidant gene expression and enzymatic activities. Yellow catfish fed two organic Mn diets had the lower mRNA expressions of endoplasmic reticulum stress-relevant gene and protein expression. Based on these observations above, dietary organic supplements (Mn-Gly and Mn-MHA) improved the growth and feed utilization, and promoted intestinal health of yellow catfish, and accordingly seems to be optimal Mn sources for yellow catfish.