The development of synbiotics bioproducts, effect on growth performance, disease resistance, digestive enzyme activity and immunological response in fry Nile tilapia, in the second-year experiment (2020), were done. The effect of synbiotics on growth efficiency, immune system, pathogen resistance, proximate composition, digestive enzymes activity and water quality of the fry Nile tilapia were studied. The experiment was divided into 2 experiments, first experiment, raring fry Nile tilapia in the aquariums (laboratory scale), the 3x3 factorial experimental design were divided into 10 experiments with 3 replicates, (Coffee silver skin: CSS) at concentrations 0%, 2.5% and 5% (CSS0%, CSS2.5% and CSS5%, respectively), probiotics (Bacillus subtilis) at 0, 5x107 and 1x108 CFU / ml (Pro0, ProA and ProB, respectively) and positive control (FOS 1% + B. subtilis 1x108 CFU / ml) was done. This experiment was 1 month period. Fry Nile tilapia fed with 5% coffee silver skin and B. subtilis 5x107 CFU/ml (CSS 5% + ProA) affected to growth promoting (increased weight gain), ADG, specific growth rate, feed efficiency ratio of fry Nile tilapia was increased significantly difference (p <0.05) compared with other experiments. There was not statistically difference (p> 0.05).
The immunity study, the fry Nile tilapia fed with dietary supplement 5% coffee silver skin and B. subtilis 5x107 CFU / ml (CSS 5% + ProA) was increases in blood lysozyme activity, bacterial inhibition efficacy by serum blood cells (Nitro Blue Tetrazolium: NBT) and Superoxide Dismutase (SOD) activity on hepatic cells of fry Nile tilapia (p <0.05). Pathogen resistance against Aeromonas hydrophila and Streptococcus agalactiae was found, high survival rate in the CSS 5% + ProA experiment. The efficacy of intestinal and gastric digestive enzyme activity of fry Nile tilapia: trypsin, chymotrypsin, protease, and amylase enzymes, were significantly increased in CSS 5% + ProA (p <0.05).
Second experiment was reared fry Nile tilapia in cages. The 3x2 factorial experimental design were divided into 8 experiments with 3 replicates, (coffee silver skin powder: CSSp at a concentration of 0.25% (CSSp 0.25%). The coffee silver skin powder was fermented with L Ultar conc enzyme: CSS at 5% concentration (CSS5%) and fructooligosaccharides (FOS) at concentrations of 1% (FOS1%) and probiotics (B. subtilis) at levels 0 and 5x107 CFU / ml (Pro0 and ProA, respectively)) were reared in cages for 2 months.
In both experiments, it was found that fry Nile tilapia fed with 5% coffee silver skin supplemented with probiotics B. subtilis 5x107 CFU / ml (CSS 5% + ProA) was effective in growth promoting, increased weight gain, ADG, specific growth rate and feed efficiency ratio of fry Nile tilapia (p <0.05) when compared to other experiments. Survival rate (%) was not statistically differences (p> 0.05). The immunity study, the fry Nile tilapia fed with dietary supplement 5% coffee silver skin and B. subtilis 5x107 CFU / ml (CSS 5% + ProA) was increases in blood lysozyme activity, bacterial inhibition efficacy by serum blood cells (NBT) and SOD activity on hepatic cells of fry Nile tilapia (p <0.05). Pathogen resistance against A. hydrophila and S. agalactiae was found, high survival rate in the CSS 5% + ProA experiment. The efficacy of intestinal and gastric digestive enzyme activity of fry Nile tilapia: trypsin, chymotrypsin, protease, and amylase enzymes, were significantly increased in CSS 5% + ProA (p <0.05).
Therefore, supplementing synbiotics affected to increase fish weight, ADG, FCR, specific growth rate, the lysozyme activity in blood, the bactericidal efficacy of serum blood cells (NBT), trypsin, chymotrypsin, protease, and amylase enzymes in intestine and stomach of fry Nile tilapia. These activities were higher than the supplementing with prebiotics or probiotics alone.
The development synbiotics bioproduct, probiotics B. subtilis was dried by mixing with Skim milk (10%) and freeze dried. After making the powder on days 0, 7, 14, 30 and 120 days, stored at 27 ? C, B. subtilis cell contents were 1.08 ? 109 CFU / g at initial day (day 0) and continue decreased when stored for 7, 14, 30 and 120 days, the viable cell count decreased to 1.06 ? 109, 8.50 ? 108, 1.46 ? 108 and 3.85 ? 107 CFU / g, respectively.