Evaluation the effect of nettle (Utrica dioica) dietary powder supplement on growth and survival indicators and the activity of liver enzymes of blood serum in common carp (Cyprinus carpio)

This research was conducted with the aim of investigating the effect of nettle powder on the growth and survival indices and liver enzymes in the blood serum (ALP, ALT, AST and LDH) of common carp juveniles. For this purpose, 180 common carp with an average weight of 5.41 ± 1.58 grams were prepared and kept in laboratory conditions for one week before the start of the experiment and fed with a commercial diet without nettle powder. Then, the fish were completely randomly divided into four treatment groups containing 0 (control), 1, 2 and 3% of nettle powder per kilogram of diet and three repetitions for each treatment, during a period of eight weeks, based on 3% of their body weight. At the end of the experiment period, the results showed that the growth indices in the treatment of 3% nettle powder with the average growth rate )11.46±2.06 (and the food conversion ratio )2.98±0.03(significantly decreased compared to the control treatment (p<0.05).The highest percentage of survival rate was observed in the 3% nettle powder treatment (77.77±3.84%), which showed a significant difference compared to the control treatment (p<0.05). Also, there was no significant difference between the treatments in the chemical composition of the tested fish carcasses (p>0.05). The examination of liver enzymes in the blood serum of fishes showed that the level of AST enzyme activity in fishes fed with 3% nettle powder had a significant increase compared to the fishes of the control group (p<0.05). In general, the results showed that nettle does not have a positive effect on growth and feeding efficiency in carp.