Effect of betaine as a feed Atractant on growth, survival and resistance to heat and salinity stressors on wild Common carp (Cyprinus carpio) juvenile

A 12-week feeding experiment was conducted to evaluate the effect of dietary betaine as a feed attractant on growth, survival and resistance to some environmental stressors on wild Common carp (Cyprinus carpio Linnaeus, 1758) juvenile. Fish by the weight of 2.51±0.07 g and density of 20 fish per aquarum. Put through Six treatments of different levels of betafin including 0 (control), 0.5%,1%, 1.5%, 2% and 2.5% added to diet containing 35% protein and 3% lipid. At the end of experiment, final growth and feeding indices including final weight ,food conversion ratio ,specific growth rate ,survival rate and resistance to environmental stressors including thermal (35°c) and salinity (35 g/lit) stress assessed. According to the results of this study, a general enhanced growth performance and feed efficiency were observed in fish fed on the diet containing 2.5% betain (P0.05). The highest of survival time after salinity and thermal challenge were observed in 2.5% betain (P