Dietary effects of procyanidin and Bio-Aqua® on hematological and immune indices of rainbow trout (Oncorhynchus mykiss)

The role of immunostimulants in reducing diseases and enhancing fish performance has been proven in various studies. In this study, the effects of antioxidant procyanidin and commercial probiotic Bio-Aqua® on some hematological and immune indices of rainbow trout (Oncorhynchus mykiss) were investigated. A total number of 525 fingerlings in seven treatments (each treatment in triplicates) with experimental diets, including (1) commercial food without supplements (CTL), (2) 400 mg procyanidin kg-1 feed (PC400) , (3) 800 mg procyanidin kg feed-1 (PC800), (4) 0.50% probiotic diet (PB0.5), (5) 1.00% probiotic diet (PB1), (6) probiotic and procianidin 0.50% and 800 mg kg-1 feed, respectively (PB0.5 + PC800) and (7) probiotic and procianidin 1.00% and 400 mg kg-1 feed, respectively, (PB1 + PC400) were fed for eight weeks. The results showed that the use of procyanidin alone did not have any significant effect on blood biochemistry and immune indices. However, the individual use of Bio-Aqua® probiotic could affect the hematological and immune indices of fish, except for monocyte, compared to the control and procyanidin treatments. However, the combined use of the supplements improved the hematological and immune indices of fish. It was concluded that the simultaneous dietary administration of procyanidin and probiotic Bio-Aqua® could improve the general health of rainbow trout.