International Journal of Aquaculture, 2018, Vol.8, No.21, 156-160
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3 Carbohydrates Requirement
The requirement of the carbohydrates changes according to species of fish. The fish of warm-water can employ
quantities much higher of diet carbohydrate than cold water fish and marine fish .The requirements in
carbohydrate are difficult to evaluate in the diets, however if carbohydrates are not provided in the diet, other
components such as protein and lipids, are catabolized for energy and for the synthesis of various biologically
significant compounds. Thus, it is significant to provide the suitable concentration of the carbohydrate according
to the mode cultivation (Sub-committee on Nutrition fish, 1993). The use of the carbohydrates in the diets of fish
changes according to the complexity of the carbohydrate.
Figure 2 Second degree relationship between specific growth rate and dietary protein levels according (Brett and Grove, 1979)
method
3.1 Carbohydrates requirement of Parachanna obscura fingerlings
Some study during 8 weeks was realized in order to evaluate the dietary effect of carbohydrate rate on
zootechnical perfomances of
Parachanna obscura
fingerlings. Five experimental diets were formulated to contain
graded rates of carbohydrate (6, 8, 10, 12 and 14%). Each diet was tested in triplicate. Zootechnical performances
improved significantly (
p
<0.05) as dietary carbohydrate level increased. Best specific growth rate and feed
efficiency were obtained with diets containing 12% of carbohydrate. In conclusion, the optimal carbohydrate
requirement of
P. obscura
fingerlings is 12% of diet (Kpogue et al., 2018).
4 Lipid Requirement
The lipids of the diets are significant sources of energy and essential fatty acids which are necessary for the
growth and the development of the fish. It also contributes to the absorption of large soluble vitamins. Lipids of
the diets, mainly in the form of triacylglycerol, are hydrolyzed by the digestive enzymes with a mixture of the free
fatty acids and 2-monoglycerides. These compounds then are absorbed and used for the synthesis of cellular
different components or catabolized for energy. The lipids of the diets of fish contain the saturated and unsaturated
fatty acids. Fatty acids can be indicated by the numbering of the methyl or carboxylic terminal. The notation of
the methyl terminal is most convenient for many feed goals. The insatured fatty acid refers normally to the acids
fatty with 18 atoms of carbon or more and the bonds two or double (Sub-committee on Nutrition fish, 1993).
4.1 Lipid requirement of
Parachanna obscura
fingerlings
Five iso-energetic diets were formulated to evaluate the effects of lipid on growth parameters, of African
Snakehead
P. obscura
fingerlings. The initial body weight was 7.69 ±0.14 g. The experimental diets contained
graded rate of lipid (5, 7, 9, 11 and 14 g/100 g of diet). Growth performances and nutrient utilization parameters
of fingerlings fed on different diets varied significantly (
p
<0.05). Highest growth performances and nutrient
utilization were obtained with fish fed on a diet containing 7% of crude lipid. According to the broken line models
