Dietary supplementation with low molecular weight sodium alginate improves growth, haematology, immune reactions and resistance againstAeromonas hydrophilainClarias gariepinus

Abstract

A few studies have illustrated the effects of sodium salt derived from alginic acid on different fish species. However, little is known about the effect of sodium alginate on catfish (Clarias gariepinus). Therefore, this study was performed to assess the use of low molecular weight sodium alginate (LMWSA) in C. gariepinus. A total of 180 apparently healthy C. gariepinus with a mean body weight of 45 g were randomly divided into three equal groups (D1, D2 and D3). D1 the control group received a control diet, while D2 and D3 received 1% and 3% LMWSA, respectively, for 8 weeks. A challenge test against Aeromonas hydrophila was performed on 15 randomly selected catfish for 15 days. At the end of the experiment, catfish in D3 that received a diet of 3% LMWSA showed significant increases in the final body weight, weight gain and thermal‐unit growth coefficient compared with those in D2 and D1. There was a significant decrease in the erythrogram in D1 after the 4‐day pathogen challenge. A leucogram revealed leucocytosis, heterophilia and lymphocytosis in catfish in D2 and D3 compared with those in D1. After the 4‐day challenge, the following changes took place: lysozyme, nitric oxide, phagocytic activity and the respiratory burst were significantly elevated in catfish that received LMWSA and were more pronounced in D3 than in D1. The mortalities of catfish have been stopped after pathogen challenge from 8‐day in D1 and D2 where at 6‐day in D3. Thus, administration of 1% and 3% LMWSA enhances the growth, immune response and resistance of C. gariepinus against A. hydrophila.

Alleviating effects of β‐glucan inOreochromis niloticuson growth performance, immune reactions, antioxidant, transcriptomics disorders and resistance toAeromonas sobriacaused by atrazine

“…Recently, the use of natural ingredients as immunomodulators for enhancing resistance and immunity in various live organisms has been proposed (Abdallah, Nasr El‐Deen, Neamat‐Allah, & Abd El‐Aziz, ; Badr et al, ; Hashem, Neamat‐Allah, Hammza, & Abou‐Elnaga, ; Neamat‐Allah, El‐Murr, & Abd El‐Hakim, ; Neamat‐Allah, Mahmoud, & Abd El Hakim, ; Prasanna, Ashraf, & Essam, ). β‐glucan (βG) is known as natural immunomodulator.…”

Citrullus colocynthis extract and synthesized Selenium nanoparticles enhance non‐specific response and resistance against Aeromonas sobria in Nile tilapia ( Oreochromis niloticus )

“…niloticus fed with Se nanoparticles demonstrated significantly enhanced lysozyme activity (Dawood et al, 2020). Several other reports indicate immunomodulatory effects of Se nanoparticles as functional supplements in fish diets (Naderi et al, 2019; Neamat‐Allah et al, 2019b, 2019a). Immunostimulants can increase non‐specific immunity by either enhancing/activating phagocytes or increasing the synthesis of molecules involved in the innate immunity such as the complement lysozyme antiprotease.…”

“…Immunostimulants are considered as an alternative for antibiotics, which will boost the immune system of the cultured organism, thus effectively countering the assault of pathogens. The use of medicinal plants/natural ingredients (whole plant, roots and leaves) and/or their extracts has been proposed as valuable feed additives to boost fish immunity and an eco‐friendly approach for the control of pathogens (Abdallah et al, 2020; Abdel‐Latif et al, 2020; Ayoub et al, 2019; Badr et al, 2011; Hashem et al, 2019; Neamat‐Allah et al, 2019b, 2019a; Prasanna et al, 2017; Yousefi et al, 2019).…”

Meta‐analysis of the use of seaweeds and their extracts as immunostimulants for fish: a systematic review

“…The seaweeds or seaweed form (e.g. sodium alginate; refined seaweed product) that was tested was often already known to have immunostimulatory action or another specific bioactivity on fish based on previous trials (Fujiki et al 1994; Cheng et al 2012; Neamat‐Allah et al 2019). Given the tremendous diversity and global distribution of seaweeds, and their widespread production of bioactive compounds (most of which are likely still undiscovered; Holdt & Kraan 2011), there is a need to investigate more seaweed species and/or more bioactive extracts.…”