Evaluation of growth performance, carcass composition and hematological indices in rainbow trout, Oncorhynchus mykiss, fed with encapsulated Lactobacillus rhamnosus

Document Type : Research Paper


1 Department of Aquaculture, Faculty of Natural Resources and Marine Science, Tarbiat Modares University, Mazandaran, Noor, Iran.

2 Department of Aquaculture, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran

3 Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Tehran, Iran

4 Department of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Golestan, Iran


The present study was conducted to evaluate the effect of probiotic bacteria Lactobacillus rhamnosus encapsulated with alginate and resistant starch (Hi maize) coated by chitosan on the growth and hematological indices as well as carcass composition in rainbow trout (Oncorhynchus mykiss). Rainbow trout fingerlings averaged 19.49 ± 0.32 g in weight were fed with diets containing encapsulated probiotic, free probiotic, and diet containing capsules without bacteria (positive control) as well as control diet without probiotics for 60 days. The results exhibited that there were significant differences in growth rate, weight gain, specific growth rate and feed conversion ratio in different groups. So that, the best results were obtained in the encapsulated probiotic group (p<0.05). The maximum carcass protein and fat were observed in the encapsulated L. rhamnosus treatment, while the maximum carcass ash was in control (p<0.05). The hematocrit and hemoglobin values in the encapsulated probiotic treatment were higher than in control. No significant differences were found in the number of white and red blood cells as well as MCV, MCH and MCHC (p>0.05). Totally, the results suggest that encapsulation of L. rhamnosus can increase the potential for probiotic employing in aquaculture.