Investigation of the effect of supplemented diet with rice husk extract (Oryza sativa) on growth performance and some related genes expression (GH, IGF-1)

the aim of this research was conducted to investigation of rice husk extract on growth performance and expression of related genes (GH and IGF-1) in ozone fish fingerlings. For this aim, the number of 120 pieces of healthy ozone fish fingerlings (50 ± 2.6 g) was purchased and then was randomly transferred in tanks with a water volume of 1000 liters. They were fed for 60 days with different levels of rice husk extract in the basic diet (crud protein: 44.5%) including 0.5 , 1 and 2 g Kg-1 of diet along with a control group (with three replicates) at the rate of 5% of body weight. At the end of the trial, growth performance was evaluated by biometrical assay completely randomly. Also, brain tissue was sampled to investigate the expression of genes involved in growth (GH, IGF-1).The results showed that feeding ozone fish fingerlings with different levels of rice husk extract had a significant effect on the growth performance and the expression of related genes in treatments compared to the control group (p<0.05). So that the best results were observed in treatment fed with 2 g of rice husk extract in per kilogram of diet (p<0.05). In general, the results showed that using rice husk extract was able to improve the growth performance and the expression of related genes involved in growth in ozone fish fingerlings, and the best level recommended in this study was 2 grams in per kilogram of diet.