the effect of dietary supplementation of probiotic "protexin" on growth performance and survival rate in sobaity seabream (sparidentex hasta)

the effect of a commercial probiotic (protexin) on growth performance and survival rate in sobaity sparidentex hasta was investigated. 240 fish with average weight of 2.99±0.87g were treated for 10 weeks. this study was carried out in a completely random design with 12 experimental groups, in 4 treatments each with 3 replicates. experimental groups were consisted of four levels of 0.0, 0.5, 1.0 and 2.0 g of probiotic protexin per kg of diet. feeding was done by hand and the fish were fed to satiation. at the end of the experimental period, growth parameters including percentage body weight gain, feed conversion rate, protein efficiency ratio, specific growth rate, daily growth rate, condition factor and survival rate were investigated. based on the results, the highest final weight, average specific growth rate, percentage body weight gain, daily growth rate, condition factor, protein efficiency ratio and also, the lowest feed conversion rate was obtained in juveniles fed with diets containing 2 g of protexin per kg of diet, and showed a significant difference with the control group (p0.05). the results of this study revealed that the addition of probiotic protexin into the diet of sobaity fish could favorably influence the growth performance in this species. among different levels of protexin used, most effective dose on growth indices would be the level of 2 g of probiotic per kg of diet.