The development of synbiotics bioproducts, effect on growth performance, disease resistance, digestive enzyme activity and immunological response in fry Nile tilapia, in the first year experiment (2019), were done. Study of endemic probiotic bacteria in the digestive system of fry Nile tilapia from Nile tilapia farms in Chiang Mai and Chiang Rai provinces, consisting of 4 farms. Effective probiotic isolates, CR4-1 and CR10-5, were selected to promote growth and inhibit pathogens.
The potential of coffee silver skin (CSS; agricultural wastes) was used as prebiotic and growth and immune stimulant in Tilapia larvae. CSS was added to supplement in fish feed for raring fry Nile tilapia. The CRD experimental designs were divided into 7 experiments and 3 replicates. First experiment was control, 2nd- 4th experiments were supplemented with CSS 0.25, 0.5 and 1% of dry weight feed, respectively. The 5th-7th experiments were supplemented with CSS extract 0.25, 0.5 and 1% of dry weight feed, respectively. All experiments were cultured for 60 days. At the end of the experiment, the specific growth rate (SGR) of fish cultured with the diet supplemented with CSS of all 6 formulas was higher than the control (p <0.05). Besides, the feed conversion ratio (FCR) of all 7 formulas was none statistically significant difference (p> 0.05).
Prebiotic properties of the CSS fermentation using U Ltra cone (CSSp-L) cellulase were tested. They have affect to the growth of probiotics (Bacillus subtilis). CSSp-L promoted the growth of probiotics which increased bacterial growth activity equivalent to the addition of glucomannan (1% MOS) and increased higher when compared to commercial prebiotics (Fructo-oligosaccharide: FOS 1%) and control diet (p<0.05). The inhibition of the pathogen growth, Aeromonas hydrophila and Streptococcus agalactiae, by measuring at 600 nm, was done. In the CSSp- L experiment showed the growth of Aeromonas hydrophila was less than control diet, 1% MOS and 1% FOS. While, Aeromonas hydrophila growth rate of CSSw-L experiment had higherthan control diet and 1% FOS. The growth of Streptococcus agalactiae in the CSSp-L and CSSw-L experiments showed less than 1% MOS and 1% FOS experiments but higher than control diet.
The first year results have been developed to be synbiotics product to promote the growth, enhance immunity and inhibit the pathogenic infection in fry Nile tilapia. The expected result will increase the commercial tilapia production and gain the potential in the market competition for Nile tilapia farmers.