Effect of dietary commercial probiotic (Bactocell) and Manan Oligosaccharide prebiotic on tolerance of Rainbow trout (Oncorhynchus mykiss) against oxygen and temperature stresses

Abstract

In this study, the resistance of rainbow trout was assayed after feeding with a commercial probiotic (Bactocel®) and Manan Oligosaccharide prebiotic in challenging with hypoxia and temperature stresses. 720 fish with average initial weight of 10±2 g under 6 feeding treatments (in 3 replicates) were tested: 1) feeding with commercial food (control), 2) feeding on 100 mg Bactocel/kg feed, 3) feeding on 2.5 g Manan oligosaccharide/kg feed, 4) feeding on 5 g Manan oligosaccharide/kg feed, 5) feeding on 100 mg Bactocel and 2.5 g Manan oligosaccharide/kg feed, 6) feeding on 100 mg Bactocel and 5 g Manan oligosaccharide/kg feed. The results showed that intestine of fish fed on both probiotic and prebiotic contained significantly higher number of probiotic bacteria. Minimum mortality under temperature stress was observed in treatments fed on both probiotic and prebiotic (P<0.05) and maximum tolerance to anoxia stress was detected in treatments 4 and 6, significantly higher compared to control group.