Effects of Dietary Protein Level on Growth Performance, Carcass Composition and Survival Rate of Fry Monosex Nile Tilapia, Oreochromis niloticus Reared under Re-circulating System

Aquaculture is nowadays developing in Senegal and has become an increasingly important source of animal protein. Tilapia, the most farmed species worldwide, is considered as the most semi-intensive cultivated freshwater fish in Senegal (NAA, 2012).

Feeding represent 40-60% of production costs in aquaculture, with protein sources accounting for significant proportion of such cost (Fotedar, 2004). It provides the essential and non-essential amino acids which are required for muscle formation and enzymatic function, on one hand, and also provides energy for maintenance, on the other hand (Yang et al., 2002). Excess protein in fish diet might be wasteful and make diet uselessly expensive (Ahmad, 2000).

One of major factors which limit economic success in any commercial farming of species is food requirement. As important dietary stuff, protein consisted of animals directly influences on the formulation of diets and therefore affects production’s cost. A wide range of feeding habits from carnivorous to herbivorous animals has been suggested as one possible reason for the wide range in protein requirements among fish species. As the main and most expensive component of the diet, protein draws greater attention in nutrition requirement studies.

Protein (most expensive macronutrient) requirement for fish fry is high and ranges from 35% to 56% (Jauncy & Ross, 1982). Furthermore, dietary protein requirements decreased with the development size and age of fish (El-Sayed & Teshima, 1991). Based on various studies general conclusion is made that tilapia fry of size <1 g requires diet with 35-50% protein, while 1-5 g fish requires diet with 30-40% protein and 5-25 g fish requires diet with 25-35% protein (Balarin & Haller, 1982).

Fry feed generally contains higher level of protein because the latter and energy requirements are higher in the early stages of life. Protein content of fry feed for tilapia farming has not been standardized yet although some farms use food stuff having 40% protein. So, it is essential to recommend the appropriate protein level of fry feed for economic production of healthy fry and maximize its lifespan as well.

However, the present study has been undertaken to conduct experimentation with different protein level diets viz. 21%, 25%, 32% 37% and 45% protein of fry feed to determine growth performance and survival rate of tilapia fry at different protein levels.

The main objective of this trial was to determine the optimum protein level which is necessary for optimum growth of monosex Nile tilapia (Oreochromis niloticus) under re-circulating system.

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(Author: Abdoulaye Loum, Mariama Sagne, Jean Fall, Diegane Ndong, Malick Diouf, Alassane Sarr, Omar Thiom Thiaw

Published by Macrothink Institute)