International Journal of Aquaculture, 2018, Vol.8, No.22, 161-167
164
Table 3 Formulation and proximate composition of experimental diet
Ingredients
Percentage (%)
Cottonseed meal
20
Maize bran
12
Fish meal
45
Soybean meal
17
a
Soya oil
2
b
Carboxymethylcellulose
1
Iron sulphate
0.5
c
Premix (Vit-Min)
2.5
Proximate analyses
Moisture (%)
88.5
Ash (%)
9.22
Crude lipid (%)
7.69
Carbohydrate (%)
13.76
Crude protein (%)
42.86
d
Brute Energy (MJ/100 g)
1.76
Protein/Energy (g/MJ)
24.35
Antinutrients
e
Phytic acid
17.4
e
Gossypol
2.0
Note:
a
Songhaï center (Republic of Benin);
b
SIGMA-Aldrich Chemie, Steinhem, Germany;
c
Drugstore, premix (vitamin-mineral)
contains (‰): Vitamin A 4,000,000 U.I; Vitamin D 800,000 U.I; Vitamin E 40,000 U.I; Vitamin K
3
1,600 mg; Vitamin B
1
4,000 mg,
Vitamin B
2
3,000 mg; Vitamin B
6
3,800 mg; Vitamin B
12
3 mg; Vitamin C 60,000 mg; Biotin 100 mg; Inositol 10,000 mg,
Pantothenic acid 8,000 mg; Nicotinic acid 18,000 mg; Folic acid 800 mg; Cholin chloride 120,000 mg; Colbat carbonate 150 mg,
Ferrous sulphate 8,000 mg; Potassium iodide 400 mg; Manganese oxide 6,000 mg; Cuivre 800 mg; Sodium selenite 40 mcg; Lysine
10,000 mg; Methionin 10,000 mg; Zinc sulphate 8,000 mg;
d
Calculated from nutrient content: 23.01 Kj/g protein; 38.07 Kj/g lipid
and 17.15 Kj/g carbohydrates;
e
By calculation using value in Table 2
Table 4 Hours and frequency of feeding
Treatments
Feeding frequency
Feeding hours
T1
2x/day
8 h
18 h
T2
3x/day
8 h
13 h
18 h
T3
4x/day
8 h
11 h 20
14 h 40
18 h
T4
6x/day
8 h
10 h
12 h
14 h
16 h
18 h
3.2 Chemicals and calculations
Standard methods for dry matter were used to analyze the ingredients and diet samples. The (oven drying) at
105°C for 24 h, crude protein (CP) (N-Kjeldahl
×
6.25) and ash (oven incineration at 550°C for 12 h) were used.
Lipids were extracted according to Bligh and Dyer (1959). Analysis of the amino acids in the ingredients was
carried out by high performance liquid chromatography (HPLC, Waters 474, Milford, MA, USA). These analyses
were carried out according to the method described by Alegria et al. (1999). Whereas gossypol was determined
according to the method described by Imorou Toko et al. (2008), phytic acid in the ingredients was acid-extracted
using 3% H
2
SO
4
for 60 min at room temperature, centri-fuged at 3,897 g for 15 min. Supernatant was mixed with
FeCl
3
(0.1 N) and centrifuged again to obtain a precipitate at which we added de-ionized water and NaOH (1.5 N)
to extract the phytate after incubation at 80°C during 30 min. After the feeding trial, fish were collected, counted,
weighed and the different parameters were calculated as follows:
Survival rate (SR) =
FN
IN
× 100
Final mean weight (FMW) =
FB
FN
