International Journal of Aquaculture, 2018, Vol.8, No.22, 161-167
163
Growth generally increased with feeding frequency up to a given limit (Wang et al., 1998; Bascinar et al., 2007;
Asuwaju et al., 2014; Jamabo et al., 2015). Indeed, according to several studies, the schedules of feed strongly
affect the ingestion and the assimilation of feed. The fish which are less frequently fed can adapt to such
conditions by consuming greater quantities of feed during each feeding. If schedules are applied for a long period,
this can lead to the hyperphagia. The fish which are well fed more frequently consume a greater quantity of; while
feed, when the intervals between the meals are short, feed crosses the digestive area more quickly, having for
result an ineffective digestion. Feed efficiency did not varied significantly with treatment (
p
˃0.05). Nevertheless,
it varied from 0.51±0.05 (T1) to 0.63±0.12 (T3). This result was an indication of better food utilization efficiency
when feeding frequency is thrice time daily. According to Jamabo et al. (2015), feeding frequency is optimal for
the condition of the trial suggesting that both growth parameters and feed utilization are most efficiency.
Therefore, optimal feeding frequency for
Parachanna obscura
fingerlings reared in controlled conditions is three
times daily. This observation agrees with the findings of several authors. According to Abid and Ahmed (2009)
and Aderolu et al. (2010), optimum feeding frequency of
Labeo rohita
and
Clarias gariepinus
fingerlings is three
times daily respectively. Moreover, three feeding a day have been found to be sufficient for maximum growth of
Oncorhynchus mykiss
(Ruohonen et al., 1998).
3 Materials and Methods
3.1 Fish and experimental design
The experiment was conducted in the experimental Station in the Wetlands Research Unit of Faculty of Abomey
Calavi University (6°25’1.53’’N, 2°20’42.2’’E). 300 fingerlings of
Parachanna obscura
(mean weight: 13.27 ±
0.07 g) were collected in a pond on the experimental station. They were stocked per a 225 liter tank for 12 weeks.
Water was continuously renewed (1 L/min). Tanks were protected at half with a perforated wooden plank to avoid
fish from jumping out. Based on nutrient of various ingredients composition (Table 2), experimental diet was
formulated (Table 3) and used during the trial. Sulfate of ferrous was used to decrease a possible toxicity of free
gossypol in the diet. The ingredients diet were ground, weighted and mixed. Feed preparation was made by
mixing the ingredients with boiling water and oil in paste. The paste was transformed into pellets of 2 mm
diameter by food blender. After freeze drying at a temperature of 28 to 35°C in lyophilisator, the pellets were
manually broken in small pieces. The fishes were fed one of four schedules (Table 4) at 3% of body weight
(Kpoguè and Fiogbé, 2012) from 08:00 AM to 08:00 PM up to apparent satiation. Each treatment was tested in
triplicate. The density of 50 fishes/tank was used.
Table 2 Composition of the main ingredients (g/100 g dry matter)
Composition
Cotton seed meal
Soybean meal
Maize bran
Fish meal
Essential
Amino-Acids
Threonine
0.45
0.76
0.20
2.31
Valine
0.50
0.56
0.20
2.77
Methionine
0.20
0.24
0.06
1.94
Isoleucine
2.50
0.52
0.13
2.45
Leucine
0.95
1.72
0.50
3.79
Phenylalanine
1.10
1.36
0.50
3.74
Histidine
0.70
0.64
0.44
1.75
Thryptophan
0.40
0.32
0.25
0.57
Lysine
0.50
1.20
0.44
4.22
Arginine
2.15
2.04
1.80
3.43
Anti-nutrients
Phytic acid
0.36
0.57
0.04
No detectable
Gossypol
0.11
Not significant
Not significant
Not significant
Physico-chemical parameters of water were measured during the experiment period. A portable chemical
multimeter parameters served to measure temperature, pH and dissolved oxygen.
Test fishing was carried every seven days. Ponds were emptied and washed. Fishes were counted and weighted
per pond. Test fishing enabled ration readjusting in relation to biomass. At the end of experiment, biomass, total
fries number, weight and individual length were measure in each pond.
