Stevia (Stevia rebaudiana) extract effect on resistance, against stress induced condensation of common carp (Cyprinus carpio)

This experiment was undertaken on Cyprinus carpio (mean body weight 12.84±1.12) to study the effect of stevia extract on growth, survival under stress due to density.
Seven hundred twenty juveniles were randomly distributed into 4 treatments each with three replicates and reared in 300 liter tanks for 2 month. Three experimental treatments were fed with stevia supplemented diet (2000ppm) and were stocked at following density respectively 3,5,10 Kg/m3 and control group were feed with non –supplemented diets and were stocked at the same densities as experimental groups.
At the end of treatments following growth parameters: condition factor, specific growth rate, relative growth rate, weight gain, length gain, food conversion ratio, protein efficiency ratio were measured. Results show that there was significant effect on all studied parameters among fish fed with stevia supplemented diet and that of the control. According to the effect of density on the studied parameters Weight gain ( 27.95± 2.33 ),Length Gain (12.7 ±0.58 ),Total length( 10.30±0.62 ), Fork length (11.16±0.58 ), Body weight increase ( 15.77±0.64 ),Length Gain ( 2.43± 0.22), Relative Growth Ratio ( 0.15±0.006 ), Specific Growth Ratio (1.38 ±0.07 ), Protein Efficiency Ratio (0.68±0.11 ),Feed Conversion Ratio (1.78 ±0.01 ), fish that were stocked at 3 Kg/m3 and were fed with stevia supplemented diet had higher value in all parameters.