Background: Montmorillonite is an alumino-silicate clay with specific physico-chemical properties such as improving growth performance, enhancing immunity. These properties make clay minerals a useful feed additive in aquaculture.
Aim: The aim of the present research was survey the effect of montmorillonite supplement on the growth performance, body chemical compositions and immune related genes of white leg shrimp (Litopenaeus vannamei).
Method: In this regard, four diets were formulated with montmorillonite supplementation at 10, 20, 30 and 40 g/kg and a diet without montmorillonite supplement was also considered as a control. Shrimps were allocated into 15 circular fiberglass tanks filled with 300 L seawater (15 shrimp per tank) and each dietary treatment replicated in triplicate for 8 weeks. Results: The mean final weight, weight gain and specific growth in shrimps fed with montmorillonite g/kg diets were higher than the control (P<0.05). Increasing the level of montmorillonite in the diet decreased the food conversion (P<0.05). The lowest amount of food conversion coefficient was observed in the treatment fed on 10 and 20 g/kg of montmorillonite diets (P<0.05). The content of fat, protein, ash and moisture of shrimps was not affected by montmorillonite (P>0.05). The highest relative abundance of heat shock protein gene mRNA transcript was in the hepatopancreas of shrimps fed and 30 g/kg diet montmorillonite. The group fed with 40 g/kg diet montmorillonite had the highest relative abundance of metallothionin mRNA transcript. The relative abundance of mRNA transcripts of lysozyme and penaedin genes in the hepatopancreas of shrimps fed with a 10 of montmorillonite g/kg diet was higher than other groups (P<0.05).
Conclusion: In general, the findings of this research showed that inclusion montmorillonite supplement in the diet improves the growth and expression of genes related to the immunity of white leg shrimp.