The effect of three African medicinal herbs used as feed additive on the growth and survival of Nile tilapia (Oreochromis niloticus) was studied. Four isoproteins (32%) and isolipid (13%) diets, namely RC (control diet or 0% plant), 3% B. vulgaris, 3% K. africana and 3% R. heudelotti, were manufactured. One hundred and eighty (180) Nile tilapia fry with an initial average weight of 0.15 ± 0.01 g were randomly distributed in 12 plastic tanks (50 L / tank) at a density of 15 fish per tank and fed three times (8.00 h am, 1.00 h pm and 5.00 h pm) per day for 90 days. For the parameters studied (average weight gain (AWG), feed conversion ratio (FCR), specific growth rate (SGR) and survival rate (SR)) no significant difference was observed between diets at the end of the experiment. Furthermore, the addition of 3% K. africana or B. vulgaris or R. heudelotti had no impact on the dry matter, ash, crude protein and whole-body fat content of Nile tilapia fry. This study showed that 3% B. vulgaris or K. africana or R. heudelotti has no adverse effect on the growth, survival and whole-body composition of Nile tilapia fry.

This study aimed to evaluate the impact of plant-based food additives on growth performance, body composition and survival of Nile tilapia. Four isonitrogenous (25% CP) and isolipidic (13% CL) experimental diets were prepared and designated as R1, R2, R3, and R4. R1 contains (3% Cymbopogon citratus), R2 contains (3% Ocimum basilicum), R3 contains (3% Mentha spicata) and R4 (control or 0% additive). 180 Nile tilapia fry with an initial average weight of 0.2g were distributed in 12 plastic tanks (50 L/tank) at the stocking density of 15 fish per tank in an isolated system. Fish were fed with experimental diets 3 times per day (8:00 am, 1:00 pm and 5 :00 pm) for 3 months. After 90 days of experiment, the results revealed that the final average weight ranged from 2.62g to 8.00g, the absolute average weight gain (AAWG) from 2.42 to 7.8g, the feed conversion ratio (FCR) from 1.31 to 2.67 and specific growth rate (SGR) from 3.06 to 4.36%/d. The survival rate (SR) varied between 64 and 100%. Of the parameters studied such as the absolute average weight gain (AAWG), the specific growth rate (SGR), the feed conversion ratio (FCR), and the survival rate, the best were obtained by the group of fish fed with the R2 diet containing 3% Ocimum basilicum. The results of the analysis of the flesh showed that the addition of 3% O. basilicum does not modify the contents of dry matter, crude protein, and ash but slightly increased the fat content. Based on the results, the inclusion of natural plant-based food additive (3% Ocimum basilicum) in the diet of Nile tilapia improved the parameters of growth, feed efficiency, and survival.

Aquaculture started in The Gambia in 1979 but is still at a rudimentary stage. Many government and private interventions conducted on fish farming failed due to the high cost of feed. Fishmeal based diets are expensive thus using them makes many fish farming in the developing countries unprofitable businesses. There is a need to use locally available plant ingredients to develop fish feeds. This study was conducted to compare the growth, feed efficiency and production cost-effectiveness of the Nile tilapia (Oreochromis niloticus) fish fed on fishmeal-based diet (control diet) to that of the same fish fed on plant-based diet (test diet). The two isonitrogenous (30 % CP) experimental diets were tested on 0.81g Nile tilapia (Oreochromis niloticus) fry for a period of six (6) weeks. The control diet composed of fishmeal, soybean meal, cassava flour, and a blend of palm oil and fish oil premixed with mineral and vitamin supplements. The plant-based diet consisted of groundnut cake, wheat flour, brewery waste and rice bran supplemented with mineral and vitamin premixes. Regarding growth performance parameters, there were significant differences between the final mean weight, mean weight gain, percentage mean weight gain and the specific growth rate of Nile tilapia (Oreochromis niloticus) fish fed on the control diet and the plant-based diet. For feed efficiency parameters, there was significant difference between feed conversion ratio for fish fed the control diet and the plant-based diet. However, there was no difference between the fish fed the two diets with regards to the protein efficiency ratio or survival rate. The plant-based diet was inferior to the fishmeal-based diet in terms of growth and feed efficiency parameters of 0.81g Nile tilapia (Oreochromis niloticus) fry. When compared to the fish-meal based diet, the plant based-diet was more cost-effective in producing a kilogram of feed but less cost-effective in producing of a kilogram of fish. Therefore, a plant based-diet cannot replace a fishmeal based-diet without compromising Nile tilapia (Oreochromis niloticus) fish growth performance and production cost-effectiveness.