Effects of dietary Arthrospira platensis supplementation on the growth performance, antioxidation and immune related -gene expression in yellow catfish (Pelteobagrus fulvidraco)

This study evaluated the effects of five isonitrogenous (405 g crude protein kg(-1) diet) and isolipidic (85 g crude lipid kg(-1) diet) diets containing 0, 5, 10, 20 and 40 g kg(-1) Arthrospira platensis on the growth performance, antioxidation and immune related-gene expression of yellow catfish (Pelteobagrus fulvidraco ). A completely randomized experimental design was developed with five treatments and three replicates. Apparent healthy and similar size fish (n = 225, 20.87 +/- 0.06 g) were randomly selected, batch weighed and stocked into fifteen 150 L fiber glass tanks at a density of 15 fish per tank. The experiment lasted for 56 days. After the growth trial, bacterial challenge test was conducted. The results showed that no obvious difference in feed intake and growth performance were found among groups (P 0.05). After A. hydrophila challenge, supplementing 40 g kg(-1) dietary A. platensis could obviously increase the level of plasma IgM, C3 and GPX (P < 0.05). A. platensis supplemented diet could decrease the level of plasma MDA and increase the activity of plasma lysozyme (LZM) (P < 0.05). Transcriptional levels of SOD , CAT , GPX , il-1 beta, il-8 , il-10 and lys genes in spleen and kidney after challenge were significantly up-regulated in 40 g kg(-1) dietary A. platensis group compared with the control group catfish (P < 0.05). Taken together, A. platensis can be introduced as a functional additive in yellow catfish diets. Inclusion of 40 g kg(-1) dietary A. platensis was found to be a suitable level to enhance the ability of antioxidant and immunity as well as no negative effects on fish growth.