Effect of Methanol Extract of Gokshura (Tribulus terrestris) on Growth Performance, Body Chemical Compositions and Activity of Antioxidant Enzymes in Grey Mullet (Mugil cephalus Linnaeus 1758)

In this study, the effect of methanol extract of Tribulus terrestris (MET) in different treatments containing control group (without using plant extract), 0.5, 1 and 1.5 g MET /kg diet on growth performance, body chemical composition and activity of oxidant enzymes of grey mullet Mugil cephalus were investigated in triplicate for 60 days. In each 60 litre 20 water tank, 20 fish with initial average weight of 8.42±0.43g were stored. At the end of the experiment, the results showed that there was no significant difference in growth parameters (FW, BWG, PER, SGR and CF), between all treatments and control group (P>0.05). Increasing of survival rate were observed in 3 and 4 compared with control treatment. The crude protein and moisture of  treatment 4 significantly increased compared to other treatments (P<0.05). The crude fat significantly decreased in 3 and 4 treatments compared to control and treatment 2 (P<0.05).The activity of superoxidedismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) enzymes have been increased more significantly in treatment 4 compared with the control treatment (P<0.05). Also, the value of malondialdehyde (MDA) was lower in all treatments compared to the control treatment (P<0.05). MDA value has been the most lowest in 3 and 4 treatments compared with the control treatment (P<0.05).So, based on the results, in order to reduce lipid oxidation and improve the carcass duality and survival status of fish, it is recommended to use 15 g methanol extract of Tribulus terrestris /kg diet of grey mullet fish.