Journal of Fisheries Science and Technology

Journal of Fisheries Science and Technology

Stress Resistance, Survival and Growth Performance of Rainbow Trout Fry(Oncorhynchus mykiss) Supplemented with a Commercial Basillus Probiotic

Authors
Hakimeh Sargazi 1
hojat Jafarian 2
saeed Yelghi 3
mohammad Farhangi 2
1 university of Gonbad
2 University of Gonbad
3 fishery Research Center
Abstract
The effect of a probiotic containing five species of bacilli at four levels of 0 (control), 1×106CFU/ml (T1), 1×107 CFU/ml (T 2) and 1×108CFU/ml (T 3) per 100g of feed on the growth performances, resistance and survival of rainbow trout fry, Oncorhynchus mykiss (463±32 mg) were compared in a 60-days feeding trial. Growth parameters, such as ADG, SGR, RGR and TGC, were significantly enhanced (p<0.05) by the probiotic at all levels, and the performance in T2 was significantly better than T1. The fish under the probiotic treatments also showed higher resistance (p<0.05) to such Environmental stresses as alkaline pH, heat and ammonia (p<0.05). No significant difference in tolerance to acidic pH stress was observed between the control and treatments. In conclusion, the probiotic bacillus highly increased the growth performances, feeding efficiency, resistance and survival in rainbow trout fry.
Keywords
Probiotic
stress
Growth performances
Feeding Efficiency