Effects of beta-glucan and some vitamins supplementing in feed on survival, growth rates and resistance to Flavobacterium columnare of tilapia (O. niloticus)

Abstract

This study was conducted in Fishery Faculty, Viet Nam National University of Agriculture to
evaluate the effects of ß-glucan and some vitamins supplementing in feed on growth, survival rate,
feed conversion ratio (FCR) and resistance to F. columnare of tilapia (O. niloticus) fry at the size of 1.0
±0.92 g/fish. The tilapia fry were allocated in 3 groups (2 experimental groups and control group). The
fish in experimental group 1 were fed with ß-glucan supplementing in feed; the fish in experimental
group 2 were fed with vitamins Chito-aqua supplementing in feed and the fish in control group were
fed with normal feed only. The experimental results showed that after 2 weeks of experiment, the
growth rate of fish in the experimental group 2 was 0.264 g/fish/day, FCR was 0.84; meanwhile, the
growth rate of fish in experimental group 1 was 0.235 g/fish/day, FCR was 0.93 and in control group
was 0.228 g/fish/day; FCR was 0.95. This proved that the growth rate of fish in the experimental group
2 was faster with lower FCR in comparison with the growth rate of fish and FCR in other groups. The
result of experimental infection with F. columnare showed that after experimental infection, the fish in
experimental group 1, 2 and control group (+) were infected with F. columnare at hour 84th and a half,
70th and 44th, respectively. The rate of diseased and death fish in experimental group 1, 2 and control
group (+) was 18.5%; 26.44% and 35.34%, respectively; and the rate of recovery fish in treatment in
experimental group 1, 2 and control group (+) was 80.1%, 70.6% and 60.2%, respectively. This was
concluded that the resistance level with F. columnare of fish in the experimental group 1 was highest.