The effect of using rice hull (Oryza sativa) extract on growth performance, haematological and biochemical parameters of beluga sturgeon (Huso huso)

Beluga sturgeon (Huso huso) is one of the important species of the Caspian Sea, and its nutrition management is one of the important goals of aquaculture in order to improve its growth and improve its immune system For this reason, the effects of rice hull extract on the growth performance, hematological and biochemical factors of beluga sturgeon were evaluated. Triplicate groups of beluga juveniles (112 ± 10 g) were placed in 12 tanks (2000) and fed with the 0, 0/5%, 1% and 2% rice hull extract for 56 days. At the end of experiment biometry was done and blood sampling was conducted. At the end of the experiment, the results showed that although the use of rice hull extract improved the growth performance, there was no significant difference between the different treatments and the control group in terms of final weight, weight gain and specific growth rate. The lowest food conversation (FCR) was observed in fish fed on 2% which had significant difference with control. However the amount of hemoglobin, hematocrit and red blood cells showed an increasing trend with increasing the administration level of the extract, no significant difference was observed between the different treatments and the control group. MCV and MCH had the highest amount in the control group and the lowest amount in the 2% treatment. MCHC showed an increasing trend in the extract treatments. However, the amount of lymphocytes and neutrophils in the fish fed with the extract showed an upward trend compared to the control group, and the highest level was measured in the 2% treatment. Also, the activity level of liver enzymes (ALT and AST) slowly increased in fish fed on rice hull extract and there were no significant differences among control, 0/5% and 1% but a significant difference was observed between the 2% treatment and the control group. Therefore, it can be concluded that rice hull extract can improve the growth performance and health status of beluga sturgeon.