International Journal of Fisheries and Aquatic Research

Authors
Roque Joel C, Vera Cruz Emmanuel C, Reyes Alvin T

Abstract
In this study, the growth, survival, length-weight relationship and condition factor of Nile tilapia fingerlings fed with Bacillus amyloliquifaciens-supplemented diet were evaluated to determine the best dosage of probiotic bacterium incorporation in feeds (T1 = 10 mL/kg, T2 = 30 mL/kg and T3 = 50 mL/kg). The fingerlings were reared for 45 days in concrete circular tanks. Basic water quality parameters were also monitored. After 45 days of rearing, the final average weights of Nile tilapia fingerlings provided with B. amyloliquifaciens-supplemented diet (T1 = 12.370±4.630 g; T2 = 12.410±45.050 g; T3 = 12.560±5.520 g) were significantly higher as compared with control (9.010±4.580 g); fingerlings fed with the highest bacterium supplementation resulted to highest final weight. Tilapia fingerlings fed with supplemented diet (T1 = 0.232±0.100 g; T2 = 0.234±0.110 g; T3 = 0.236±0.120 g) had significantly higher AGR as compared with control (0.157±0.100 g); the best AGR was acquired using Treatment 3. The same result was observed at SGR wherein treatments (T1 = 3.970±0.879%; T2 = 3.920±1.051%; T3 = 3.930±1.059%) were significantly higher than the control (3.150±1.112%); the highest SGR was recorded in Treatment 1. There was no significant difference observed between control (84.670±5.030%) and treatments (T1 = 88.000±10.580%; T2 = 86.000±3.460%; T3 = 82.000±12.170%) in terms of per cent survival; the highest per cent survival was recorded in Treatment 1. In the LW relationship, value of exponent b provides information on fish growth. Except T2 which was positive allometric growth, all of them (Control, Treatment 1, Treatment 3) were classified as negative allometric. Negative allometric means that the organism grows slender, so it gains length faster than weight; while positive allometric means that the organism becomes stouter as it increases in length, so it gains weight faster than length. The LW relationship equation of control was W = 0.184 L^2.9115, W = 0.202 L^2.8612 for Treatment 1, W = 0.168 L^3.0524 for Treatment 2 and W = 0.180 L^2.9771 for Treatment 3. The highest condition factor was recorded in Treatment 1 (K = 2.764±1.545) and this was significantly higher as compared to control (1.994±0.947), Treatment 2 (1.624±0.341) and Treatment 3 (1.959±0.280).