Effects Of Dietary Fructooligosaccharides On Growth Performance, Serum Biochemical Indexes And Intestinal Microflora Of (Oreochromis Niloticus×O.Aureus)

The experiment was conducted to investigate the effect of different concentrations of dietary fructo-oligosaccharide(FOS) and adding the prebiotic (FOS), probiotics (Bacillus subtilis), antibiotics (CTC) on the growth performence,serum biochemical indexes,nonspecific immunity and intestinal microflora of Oreochromis niloticus×O. Aureus.In experiment 1,tilapia were randomly divided into six treatments with three replicates per treatment and thrity tilapias per replicate.Diets containing FOS 0%(control group),0.1%,0.2%,0.3%,0.4%,0.5% were fed to tilapia with initial body weight of lOg for 8 weeks to investigate the effect of adding FOS in diets on growth performance,serum biochemical indexes,serum nonspecific immune index and intestinal microflora of (Oreochromis niloticus×O.-aureus).Compared with the control group,adding with 0.4% -0.5%FOS weight growth rate were significantly increased 24.45% and 28.27% (P <0.05),FCR were significantly decreased 13.87% and 18.98% (P<0.05). Serum total protein, albumin rised, adding 0.4%,0.5% FOS group was significantly higher than control group (P<0.05).Serum acid phosphatase, alkaline phosphatase, superoxide dismutase, lysozyme added 0.4%,0.5% FOS group was significantly higher than control group (P<0.05).Added 0.4%,0.5% FOS group intestinal Bifidobacterium, Lactobacillus was significantly increased compared with the control group, E. coli, Salmonella, significantly lower than the control group (P<0.05).The FOS supplement in diets is suggested to be 0.4%-0.5% for tilapia.In experiment 2:tilapia were randomly divided into five treatments with three replicates per treatment and thrity tilapias per replicate.Diets containing FOS 0%(control group),0.4% FOS,0.2% Bacillus subtilis, 0.4% FOS+0.2% Bacillus subtilis,0.1% chlortetracycline were fed to tilapia with initial body weight of 20g for 8 weeks to investigate the effect of adding three of supplements in diets on growth performance,serum biochemical indexes,serum nonspecific immune index and intestinal microflora of (Oreochromis niloticus XO.-aureus).The results showed that compared with control group, adding 0.4% FOS+0.2% Bacillus subtilis,0.1% chlortetracycline group were significantly increased 29.43% and 27.18% (P<0.05), SGR in each group were improved, which added 0.4% FOS+0.2% Bacillus subtilis,0.1% chlortetracycline group was significantlyincreased 17.18% and 15.95% (P<0.05),adding 0.4% FOS +0.2%Bacillus subtilis,0.1% chlortetracycline group of FCR was significantly decreased 21.58% than the control group (P<0.05) Compared with the control group, the treatment groups decreased serum T-Cho, adding 0.4% FOS+0.2% Bacillus subtilis,0.1% chlortetracycline group were significantlydecreased by 22.84%,24.28%(P<0.05), Adding 0.4% FOS +0.2% Bacillus subtilis group serum acid phosphatase, alkalinephosphatase, superoxide dismutase, lysozyme were significantly increased(P<0.05),bifidobacteria, lactic acid bacteria were significantly increased(P<0.05), compared with the control group.E. coli, Salmonella, were significantly decreased(P<0.05)than the control group.In summary, FOS,Bacillus subtilis and chlortetracycline supplements in tilapia diets can increase their growth performance, nonspecific immunity and the intestinal microbial environment,.Combined with FOS and Bacillus subtilis can replace the antibiotics.