Objective: To compare the the effects of the diets containing various fish viscera meal and effects of probiotic bacteria (Lactobacillus sp., Bifidobacterium sp. and Streptococcus sp.) on the growth, survival and carcass composition of rainbow trout larvae. Methods: Twelve tanks consisting of triplicates for each treatment group were used. Triplicate groups of rainbow trout (176 mg bodyweight) were fed with three diets formulated with viscera meal (VM) derived from common carp (Cyprinus carpio), or VM derived from mullet (Liza saliens and Liza auratus) or commercial diet with in-tank probiotic respectively, and three diets without probiotic 4 times a day at 5% to 6% of body weight for 45 d. Rainbow trout larvae (average individual weight, 176 mg) were randomly distributed with density of 4 fish/ L into 18 fiberglass tanks. In probiotic treatments a blend of selected bacteria at 104 CFU/mL were added into rearing tanks four times a day. At the end of the 45-day experiment, growth performance, survival rates and carcass composition of larvae were determined. Results: The results indicated that change to probiotic diets significantly affect growth and survival of rainbow trout larvae (P<0.05). Rainbow trout larvae fed with commercial diet with in-tank probiotics showed the highest survival rates (98%), total weight (2 226 mg) and specific growth rates (7.16%/d) among treatment groups. Conclusions: VM derived from common carp can successfully replace more than half of marine fish meal in formulated diets for rainbow trout. Use of in-tank blends of Lactobacillus sp., Bifidobacterium sp. and Streptococcus sp., can increase survival rates and specific growth rates in rainbow trout larvae.
کلید واژگان :Rainbow trout, Fish viscera meal, Probiotic
ارزش ریالی : 300000 ریال
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