International Journal of Aquaculture, 2017, Vol.7, No.1, 1
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ingredients were first ground to a small particle size (approximately 250 mm). The basal diet composition was
showed in Table 1. Four experimental diets were formulated including the control as basal diet (D1) without any
supplementation, followed by three diets supplemented with moringa leaves meal which added simply to basal diet
at 2, 4 and 6 g kg
-1
(D2, D3, D4, respectively). Dehydrated components were carefully mixed before adding water at
rate of about 40% moisture. The experimental diets were formulated by a mincer with die into 1-mm diameter
spaghetti-like strands, sun dried and stored in airtight containers. The composition analysis of the experimental diets
was determined according to AOAC methods (2000).
Table 1 Ingredient composition and proximate analysis of the basal diet fed to juvenile tilapia (
Oreochromis niloticus
) for 12 weeks
Ingredients
%
Soybean meal (44 % CP)
44.5
Wheat bran (14 % CP)
25.0
Yellow corn meal
21.0
Soybean oil
4.0
Mineral and vitamin premix
1.0
L- Methionine
1.0
L- Lysine
0.5
Di- Calcium phosphate
1.0
Molasses
Proximate composition %
2.0
Moisture
10.7
Crude Protein
26.3
Crude fat
9.8
Ash
7.3
Gross energy (kjg
-1
diet)
7
Note: Premix supplied the following vitamins and minerals (mg or IU) kg-1 of diet, vitamin A, 8000 IU; vitamin D3, 4000 IU;
vitamin E 50 IU; vitamin K3, 19 IU; vitamin B2, 25 mg; vitamin B3, 69 mg; vitamin B6, 20 mg; nicotinic acid, 125 mg; thiamin, 10
mg; folic acid, 7 mg; biotin, 7 mg; pantothenate, 15 mg; vitamin B12, 75 mg; choline, 900 mg; vitamin C, 500 mg; manganese, 350
mg; zinc, 325 mg; iron, 30 mg; iodine, 0.4 mg; cobalt 2 mg; copper, 7 mg; selenium, 0.7 mg and 0.7 mg butylated hydroxytoluene
according to Xie, Cui,Yang and Liu (1997)
1.2 The experimental fish and facility
Nile tilapia,
Oreochromis niloticus
fingerlings were obtained from a local fish hatchery (Saft Khaled, Bahira, Egypt).
Fish were randomly distributed in twelve 80-L glass aquaria with 15 fish each with an initial average weight 2.1 ±
0.1 g. The aquaria were supplied with aerated and chlorine free fresh water at a rate of 250 mL/min. The
experimental diets were fed to three replicates of fish three times per day at 9.00 a.m., 11 a.m. and 13.00 p.m. at rate
of 5% of body weight for 12 weeks feeding. Every two weeks the fish from each aquarium was counted and weighed.
The aquaria were cleaned daily and two thirds of the water replaced before feeding. Every other day water
temperature and dissolved oxygen was measured using oxygen meter. PH was monitored twice weekly using pH
meter (pH pen; Fisher Scientific, Cincinnati, OH). During the 12-week feeding trial, the water-quality parameters
averaged (
SD): water temperature, 28
0.9°C: dissolved oxygen, 6.5
0.5 mg
–l
; pH, 7.5
0.2.
1.3 Analytic procedure
Fish body composition was analyzed according to standard procedures (AOAC, 2000). Counting and weighing fish
at the end of the feeding study to calculate percent weight gain (PWG; [BW – initial BW] ×100/initial BW), feed
conversion ratio (FCR; dry feed consumed/WG), feed efficiency ratio (FER; WG/ dry feed consumed), protein
efficiency ratio (PER; WG/protein intake), specific growth rate (SGR; [ln final BW – ln initial BW] ×100/days),
and survival ([no. of fish at the end of the experiment/no. of fish at the beginning of the experiment] ×100). Initial
sample of 15 fish was collected randomly and frozen at the beginning of the study at -18°C for analysis of whole
body composition. By the end of the feeding trial, six fish from each tank were sampled for biochemical analysis.
