Effects of dietary microencapsulated sodium butyrate on growth, intestinal mucosal morphology, immune response and adhesive bacteria in juvenile common carp (Cyprinus carpio) pre-fed with or without oxidised oil

Abstract

The aim of the present study was to investigate the effects of different dietary sustained-release microencapsulated sodium butyrate (MSB) products (0 (non-supplement), 1·5 and 3·0 h) for a control or oxidised soyabean oil (SBO) diet on fish production, intestinal mucosal condition, immunity and intestinal bacteria in juvenile common carp (Cyprinus carpio). Dietary MSB increased weight gain and reduced the feed conversion ratio within the control and oxidised SBO groups. Gut mucosa was damaged in the oxidised SBO group fed without MSB, in contrast to a normal appearance found in fish fed the MSB1·5 and MSB3·0 diets in the oxidised SBO group. Microvillus density increased in fish fed the MSB1·5 and MSB3·0 diets in the oxidised SBO group (P,0·001); however, microvillus density was affected by the different pre-fed diets in the midgut (P,0·001) and by the different sustained-release times of MSB in the distal gut (DG) (P¼0·003). The interaction between the pre-fed diets and the sustained-release times of dietary MSB was significant for the relative gene expression levels of gut heat shock protein-70 (HSP70), pro-inflammatory cytokines (IL-1b and TNF-a) and anti-inflammatory cytokines (transforming growth factor-b) within each gut segment, except for HSP70 in the DG and IL-1b in the foregut. Modulation of adherent bacterial communities within each gut segment investigated was not obvious when the common carp were fed the diets with MSB, as similarity coefficients of .0·79 were observed. These results indicated that MSB can be used as a dietary supplement to repair or prevent intestinal damage in carp fed oxidised SBO.Key words: Cyprinus carpio: Microencapsulated sodium butyrate: Oxidised soyabean oil: IntestineThe use of antibiotics as growth promoters is a subject of debate in animal production as well as in feed and food industries. Their application in animal feed creates the possibility of building resistance to antibiotics used against bacterial pathogens in animals and humans (1,2) as well as in fish (3) . In 2006, the European Union banned the use of antibiotics in animal feed as growth promoters (European Parliament and Council Regulation no. 1831/2003). Another issue of concern with fish diets is that lipids are rapidly oxidised during storage due to the high content of PUFA, even though synthetic antioxidants such as butylated hydroxyanisole, butylated hydroxytoluene and tert-butyl hydroquinone are supplemented. Furthermore, some plant extracts are used as feed additives in many countries to retard or prevent oxidative deterioration of oil (4) . The products of lipid oxidation such as SCFA, aldehydes and ketones do not only decrease the nutritive value of the feed but also react with cellular membrane components such as protein and DNA (5) . Several studies have reported † Both authors contributed equally to this work.* Corresponding authors: D. M. Gatlin, email d-gatlin@tamu.edu; Z. Zhou, fax þ86 10 82106054, email zhou_zg@msn.comAbbreviations: C-0, basal diet followed by basal diet; C-1·5, basal...

Gene Expression Profiling Reveals Functional Specialization along the Intestinal Tract of a Carnivorous Teleostean Fish (Dicentrarchus labrax)

“…This receptor has anti-inflammatory properties acting as the metabolite sensor of butyrate, the end product of the microbial fermentation of dietary fiber (Singh et al, 2014). This short-chain fatty acid has been considered a promising feed additive in aquaculture, improving the immunological status and intestinal condition in carp ( Cyprinus carpio ) (Liu et al, 2014). Recent data also support the promising effects of butyrate supplementation in European sea bass, and Rimoldi and co-workers have found reported improved growth and increased gene expression of the oligopeptide transporter 1 ( PEPT1 ) in the hindgut of fish fed low-fish meal diets (unpublished).…”

The utilization and mode of action of organic acids in the feeds of cultured aquatic animals

“…Liu et al . () observed slight alterations in the adherent bacterial communities within the gut segments of common carp fed 0.3 g kg −1 Na‐butyrate diets. Zhou et al .…”

“…In common carp, it had similarly been reported that the intestinal mucosal morphology was not significantly altered when fish were fed diets supplemented with Na‐butyrate although some differences were observed in microvillus height (Liu et al . ). Apart from the slight improvement in weight gain, FCR and immune responses, it was reported that dietary Na‐butyrate seemed to be able to prevent or repair the intestinal mucosal damage and increase the microvillus density in carp prefed with oxidized soya bean oil.…”

Dietary Butyrate Helps to Restore the Intestinal Status of a Marine Teleost (Sparus aurata) Fed Extreme Diets Low in Fish Meal and Fish Oil

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