| dc.description.abstract | Increasing price of dietary fishmeal is offsetting the excellent growth and yield induced in
farmed Nile tilapia subsequently reducing the corresponding cost-effectiveness. Replacement
of the dietary ingredient with better or comparable substitutes has become necessary in many
countries including Uganda. In light of the phenomenon, a study was conducted in Busoga
sub-region of Eastern Uganda to evaluate the biological and economic performance of
pondcultured Nile tilapia (Oreochromis niloticus L.) fed on peanut-based meals as alternative
to dietary fishmeal. Sample surveys supplemented by field experiments attained all the
specific objectives of the study from January 2016 to March 2017. The specific objectives of
the study related the following performance indicators in Nile tilapia fed on the test diets;
biomass production (g/pond), Feed Conversion Ratios, Relative Growth Rates (%), Net Fish
Yields (g/pond), Survival Rates (%), Economic Conversion Ratios and Profit Indices. The
surveys that valuated the test feeds and fish products occurred in sampling units in local
commodity markets in Iganga municipality and along the main roads network respectively.
The fish pond input and output valuations (USD/Kg) were conducted directly and indirectly
respectively. The field experiments aimed at measuring targeted responses induced by test
diets in Nile tilapia. Each of the two experimental sites at Busoga University farmland
consisted of rectangular shaped earthen ponds. Two experimental sites A and B were stocked
in the dry and wet seasons respectively. The replication of Site A at Site B aimed at mitigating
the effect of weather on fish production. Forty-eight mono-sex fish fingerlings were stocked
in sixteen pond units of uniform size (3.0 x 4.0 x 1.0 cubic meters) at each site. Among the
stocked ponds, one acted as a fish reserve pond for mitigating the risk of fish loss in the earthen
ponds. Mean body weights at stocking were 22.2 and 21.7 grams for the sites A and B
respectively. Test diets were Iso-caloric throughout the experiments (5.3627 Kcal/g) and isonitrogenous;
30% and 25% Crude Protein for the first twelve and latter weeks respectively.
Dietary treatments included the fishmeal-based diet (control) and two peanut-based diets;
peanut meal and mixed plant meal-based diets. The locally available commercial feed for
grow-out Nile tilapia containing 25% Crude Protein was the control diet throughout the
feeding trials. The results indicated that only unionized ammonia affected fish biomass
production negatively. Survival Rates in Nile tilapia were the only performance indicators that
were insignificantly different (p 0.05) across all the dietary treatment groups. Other
Insignificant differences (p 0.05) among other indicators of performance were restricted
were restricted the fishmeal and mixed plant-based diets. With exception to the Survival Rates,
the peanut-based diet exhibited significantly poorer (p 0.05) results than the fishmeal-based
diet. The lack of significant differences (p>0.05) across all tested biological and economic
performance indicators implied that the mixed plant meal based and fishmeal-based diets
exhibited comparable performances. Therefore, among the peanut-based meals, only the
mixed plant-meal should completely substitute the conventional fishmeal-based diet in the
pond cultured Nile tilapia in Uganda. | en_US |
