Nano-selenium supplementation in plant protein-based diets changed thyroid hormones status and hepatic enzymes activity in Acanthopagrus arabicus female broodfish and their offspring

A feeding trial was conducted to assess the effects of nano-selenium (n.Se) supplementation in a plant protein (PP)-based diet on female Acanthopagrus arabicus broodfish and their offspring. Two basal diets were prepared: a fish meal (FM)-based diet (FM-control) as a positive control and a PP-based diet. The PP-based diet was supplemented with n.Se at five levels including 0 (PP-control, as a negative control), 0.5, 1, 2, and 4 mg/ Kg. Brooders were fed for 90 days with one of the six experimental diets. Supplementing the PP-based diet with 2-4 mg n.Se/Kg markedly enhanced survival rate in 3-day post-hatch larvae (3DPH) larvae and total body length in newly born and 3DPH larvae. Serum triiodothyronine (T3) significantly decreased in females by supplementing PP-based diet with 1-4 mg n.Se/kg, meanwhile, serum thyroxine (T4) increased in females fed 1-4 mg n.Se/kg PP-based diets. The level of serum T3 in females fed FM-based diet was lower than those fed PP-based diet without n.Se supplementation (0.6 vs. 1.9 nmol/L-1). Meanwhile, the serum T4 was markedly higher in broodfish fed the FM-based diet than those fed the PP-based diet (21.9 vs. 14.3 nmol/L-1). The levels of T3 and T4 in 3DPH larvae originating from females fed the PP-based diet without n.Se supplementation were lower than in FM-based and n.Se supplemented PP-based groups (P < 0.05). Serum alkaline phosphatase (ALP) increased in females with increasing n.Se level in the PP-based diet. The highest and lowest ALP levels were in 3DPH larvae originating from females fed PP-based diet without n.Se supplementation and those fed with 1 mg n.Se/Kg PP-based diet, respectively (P < 0.05). The results of the present study suggest supplementing 2-4 mg n.Se in a PP-based diet can improve performance in A. arabicus brooders and larvae that are associated with modulation of thyroid hormones in this species.

Automated summary

The study demonstrates that supplementation of nano-selenium in a plant protein-based diet improves the performance of A. arabicus broodfish and larvae, with the modulation of thyroid hormones playing a role.