Investigation of Potential Probiotic Bacterium (Bacillus subtilis CCI3) in the Formulated Diets on Immunity, Growth Performance and Nutritional Quality of Cyprinus carpio

Abstract

In the present investigation Bacillus subtilis CCI3 was evaluated for use as a probiotic supplement in the feeds for the fingerlings of Cyprinus carpio. The outcome of supplement on the feed utilization efficiency, growth performance, and immune response was evaluated.  Cyprinus carpio fingerlings (avg. wt. 27.75 ± 0.045 g) were fed feed supplement with 2 x 104 (feed BS1), 2 x 105 (feed BS2) and 2 x106 (feed BS3) Bacillus subtilis cells per 100g feed for 60 days @ 5 % of the body weight per day in two equal installments in triplicate treatments. The control diet (CC) was not supplemented with the Bacillus subtilis. All the feeds are isocaloric and isonitrogenous. Feed BS2 fed fishes showed better growth, significantly (p ≤ 0.05) higher protein efficiency ratio (PER), highest RNA: DNA ratio and a lower feed conversion ratio (FCR) than the other experimental feeds. Feed BS2 fed fishes also showed highest carcass protein and lipid than the others. Intestinal protease and α – amylase activity was observed significantly higher (p ≤ 0.05) in BS2 feed treated fishes and also significantly (p ≤ 0.05) greatest GPT and GOT values were observed in feed BS2 fed fishes but lowest in control (C). Highest TSP, albumin, globulin was observed in BS2 treated fishes after 60 days feeding trial. But lowest glucose level was observed in the same treatment. TEC, TLC, Hct and Hb values were highest in BS2 treated fishes. After feeding trial the specific and non-specific immunity levels and disease resistance of fish were also studied. NBT, antibody titer and serum bacterial activity were highest in diet BS2 fed fishes. After feeding trial the fishes were challenged for 10 days by bath exposure to Aeromonas sp. (A2) [105 CFU ml-1, 1hr. and after 7 days 107 CFU ml-1, 1hr].