No abstract

Due to the emergence of antibiotic-resistant pathogens, probiotics in aquaculture are used for the prevention of infectious microbial diseases and substitute for antibiotics and chemotherapeutics. In this study, we evaluated the effect of probiotic Bacillus spp. isolated from African nightcrawler (Eudrilus eugeniae) on the growth, feed utilization, and disease resistance of Nile tilapia (Oreochromis niloticus). Four probiotic strains of Bacillus spp. (ANSCI9, BFAR9, RM3, and RM10) were individually incorporated in the commercial diet (control) at 10 8 CFU g -1 of feed. The experimental fish were fed at 5% of their body weight for 30 days, and subjected to a 14-day Aeromonas hydrophila challenge test afterward. The results showed the probiotic-treated groups have higher (P<0.05) average body weight (ABW) (4.51 ± 0.34 g) than the control (3.89 ± 0.17 g). The BFAR9 (2.73 ± 0.26 g) and RM10 (3.15 ± 0.30 g) showed higher (P<0.05) absolute growth (AG) than the control (2.20 ± 0.16 g). Furthermore, RM10 had higher (P<0.05) specific growth rate (SGR) (1.60 ± 0.10 % day -1 ) and relative growth rate (RGR) (181.39 ± 18.16 %) than the control (SGR=1.29 ± 0.07 % day -1 ; RGR=129.84 ± 9.77 %). Consequently, RM10 had significantly lower (P<0.05) feed conversion ratio (FCR) (1.99 ± 0.13) than the control (2.60 ± 0.16). The challenge test revealed that the probiotic-treated groups have higher (P<0.05) survival (81.25 ± 9.57 %) than the control (55.00 ± 19.15 %). These results revealed that the probiotic Bacillus spp. isolated from E. eugeniae improved the growth, feed utilization, and the disease resistance of Nile tilapia.

No abstract

Due to the emergence of antibiotic-resistant pathogens, probiotics in aquaculture are used for the prevention of infectious microbial diseases and substitute for antibiotics and chemotherapeutics. In this study, we evaluated the effect of probiotic Bacillus spp. isolated from African nightcrawler (Eudrilus eugeniae) on the growth, feed utilization, and disease resistance of Nile tilapia (Oreochromis niloticus). Four probiotic strains of Bacillus spp. (ANSCI9, BFAR9, RM3, and RM10) were individually incorporated in the commercial diet (control) at 10 8 CFU g -1 of feed. The experimental fish were fed at 5% of their body weight for 30 days, and subjected to a 14-day Aeromonas hydrophila challenge test afterward. The results showed the probiotic-treated groups have higher (P<0.05) average body weight (ABW) (4.51 ± 0.34 g) than the control (3.89 ± 0.17 g). The BFAR9 (2.73 ± 0.26 g) and RM10 (3.15 ± 0.30 g) showed higher (P<0.05) absolute growth (AG) than the control (2.20 ± 0.16 g). Furthermore, RM10 had higher (P<0.05) specific growth rate (SGR) (1.60 ± 0.10 % day -1 ) and relative growth rate (RGR) (181.39 ± 18.16 %) than the control (SGR=1.29 ± 0.07 % day -1 ; RGR=129.84 ± 9.77 %). Consequently, RM10 had significantly lower (P<0.05) feed conversion ratio (FCR) (1.99 ± 0.13) than the control (2.60 ± 0.16). The challenge test revealed that the probiotic-treated groups have higher (P<0.05) survival (81.25 ± 9.57 %) than the control (55.00 ± 19.15 %). These results revealed that the probiotic Bacillus spp. isolated from E. eugeniae improved the growth, feed utilization, and the disease resistance of Nile tilapia.

A 35-day feeding experiment was conducted to evaluate the effects of pulverized wood charcoal (PWC) on the growth, feed utilization, survival and waste excretion of red tilapia (Oreochromis sp.). Ninety red tilapias with an initial weight of 7.32 ± 1.31 g were acclimatized and randomly introduced into 9 aquaria in 3 groups with 10 fish per aquarium. Different levels of PWC (0 (T0), 1% (T1), and 2% (T2)) were incorporated in the diets of red tilapia for four weeks. After the experiment, average body weight (ABW), specific growth rate (SGR), relative growth rate (RGR) weight gain (WG), feed conversion ratio (FCR) and survival rate (SR) of the experimental fish were computed. No significant differences were observed on feed utilization, survival, and waste excretion of the fish. Furthermore, ABW and WG of the experimental fish did not show any significant difference, however, significantly higher (P < 0.05) SGR and RGR were observed from T1 compared to the other treatments. Consequently, this study showed that supplementation of 1% PWC in the diet is the most suitable in improving the growth performance of red tilapia.