International Journal of Aquaculture 2015, Vol.5, No. 41, 1-20
3
purchased from Bodija main market in Ibadan, which
is located in the western part of Nigeria. Raw whole
seeds were subjected to heat treatment (Nwanna, 2005)
by roasting on a metal plate at 120°C for 30-45
minutes, after which they were grinded using a
manually operated grinding machine, sundried,
packed into plastic bags, and stored at ambient
temperature prior to inclusion in the formulation of
with other feeding stuff for the fish. All diets were
formulated without added wheat,
inorganic
phosphorus and amino acid supplements to optimize
phytate hydrolysis in the diets. Pearson’s method of
diet formulation was used to formulate and prepare
dietary proportions, which was subsequently mixed
in a large bowl with clean cold water and
cold-pelleted using a sieve of mesh size 2mm to
produce a noddle-like strand of feed. Pelleted feeds
were sun-dried and packed air-tight polythene bags
before use. A stock solution of liquid Natuphos®
phytase (Natuphos 5000L, BASF Corporation.,
Germany) was prepared by using a dilution factor of
1:10 and bulk density of 1.2g/cm3 (1.15-1.25g/cm3)
(BASF, 2014) from which 0.4917ml, 0.9833ml,
1.475ml, and 1.967ml/kg diets for 250, 500, 750, and
1000 FTU/g phytase, respectively, were taken and
supplemented in the diets according to the design.
Phytase was supplied by BASF Corporation,
Ludwigshafen, Germany, while phytase activity of
all experimental groups were analysed by BASF SE,
Lampertheim, Germany. Both phytase and non
phytase-supplemented groups were analysed for total
phosphorus and calcium (AOAC, 1990), phytate
phosphorus (Oberleas, 1973), and phytase activity
(Oberleas, 1973). The control diets, fish meal diets,
S0 (100% fish meal) and commercial were not
supplemented with phytase. Proximate, mineral and
antinutrients composition of raw and processed
soyabean (roasted) are presented in Tables 1-4, while
the gross and chemical composition of the basal diet
is shown in Table 5.
Table 1 Proximate composition of feed ingredients
Ingredient
Crude protein
(%)
Fat (%)
Ash (%)
Fibre (%)
Moisture (%) CHO (%)
Energy
(kcal/100g)
Fish meal
66.46±0.01 5.32±0.01
4.33±0.03
0.69±0.01
9.28±0.04
13.79±0.62 380±0.10
SBM (Full-fat) 42.93±0.07 18.41±0.01 5.34±0.01
7.86±0.01
8.47±0.01
17.00±0.06 420±0.01
SBM (Raw)
35.5± 0.05 19.48±0.01 5.06±0.01
5.59±0.01
12.13±0.03 22.25±0.04 420±0.00
Maize
10.24±0.01 3.32±0.01
1.28±0.01
1.15±0.01
10.35±0.01 73.67±0.03 370±0.00
Table 2 Mineral composition of feed ingredients
Ingredient
Phosphorus (%)
Calcium (%)
Magnesium (%)
Potassium (%)
Sodium (%)
Fish meal
2.25±0.01
4.60±0.01
1.06±0.01
79.20±0.02
16.13±0.03
SBM (roasted, full fat)
0.75±0.01
0.64±0.01
0.27±0.02
1.61±0.05
26.20±3.61
SBM (raw)
0.53±0.01
0.86±0.01
0.26±0.01
2.11±0.01
20.60±0.01
Maize
0.28±0.01
0.30±0.01
0.13±0.01
0.39±0.01
0.01±0.01
Table 3 Mineral composition of feed ingredients
Ingredient
Manganese (%)
Iron (ppm)
Copper (ppm)
Zinc (ppm)
Fish meal
16.13±0.03
96.61±0.05
2.75±0.05
48.45±0.05
SBM (roasted, full fat)
50.75±6.03
89.77±2.25
7.21±1.48
27.65±0.24
SBM (raw)
80.01±0.01
101.23±0.02
4.09±0.01
9.30±0.01
Maize
5.00±0.02
37.00±0.01
2.01±0.01
21.02±0.02
Table 4 Anti-nutrients in feed ingredients
Feed ingredients
Tannin (mg/g)
Phytate (mg/g)
Oxalate (mg/g)
SBM (Raw)
0.43±0.02
0.61±0.01
7.48±0.12
SBM (Roasted)
0.05±0.06
0.50±0.02
3.58±0.20
Fish meal
0.00±0.00
0.13±0.03
0.49±0.09
Maize
0.00±0.00
0.27±0.03
0.795±0.05
