Effect of Enriched Artemia parthenogenetica with Probiotic (Bacillus spp.) on Growth, Survival, Fecal Production and Nitrogenous Excretion in Rainbow Trout(Oncorhynchus mykiss) Larvae

Abstract

This study was carried out to evaluate the effect of Probiotic (Bacillus spp.) on growth and survival rate and nitrogenous excretion in Rainbow Trout (Oncorhynchus mykiss) larvae. Rainbow Trout larvae were fed on Artemia parthenogenetica nauplii enriched at suspension of five probiotic bacilli at doses of 0, 1×10 8 , 2×10 8 and 3×10 8 (CFU l -1 ).The feeding level was 30 percent of total biomass per day. The daily ration was divided into four feeding portions. The end all the trout larvae were sampled for biometry and growth determination. Feces were collected twice a day by pipetting and ammonia and urea contents in each tank were determined. Results showed that, with the inoculating of probiotic Bacilli in suspension of broth, trout larvae survival and growth parameters generally increased. Fish larvae fed with enriched Artemia nauplii at dose of 2×10 8 CFU l -1 in suspension of broth had significantly higher survival and growth parameters than the control group (p<0.05). Ammonia excretion, urea excretion and fecal production decreased in experimental treatments (p<0.05). Then, our results confirm the potential of probiotic bacillus had promoted effects on enhancement of survival rate and growth performance in experimental treatments and probiotics can reduce ammonia and urea excretion in Rainbow trout larvae.