Browsing by Author "Iwe, Gerald"

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    Dietary amino acid requirements of pebbly fish, Alestes baremoze (Joannis, 1835) based on whole body amino acid composition
    (Aquaculture Reports, 2019) Kasozi, Nasser; Iwe, Gerald; Sadik, Kassim; Asizua, Denis; Tibenda Namulawa, Victoria
    Alestes baremoze is a valuable food fish with a wide geographical distribution in East, North and West Africa. Currently, the nutritional requirements of A. baremoze have not yet been determined, which hinders attempts towards developing appropriate feed formulations for its culture. This study was thus conducted to estimate essential amino acid (EAA) requirements of A. baremoze using the A/E ratio method, as a guide in formulating its diet. Fish samples used in the study were categorised into four classes according to their fork lengths (1–12 cm; 13–24 cm; 25–36 cm and 37–48 cm), with each class consisting of 10 fish. Results from the amino acid composition analysis revealed significant difference (P<0.05) in the concentration of tryptophan, lysine, methionine, threonine, phenylalanine, isoleucine and valine amongst the different class sizes of A. baremoze. The A/E ratios of A. baremoze muscle tissue were in the same range with those obtained from other fish species, except for tryptophan. When expressed as a percentage of dietary protein, the EAA requirements of A. baremoze, were however not significantly different (P > 0.05) within the four classes. The EAA requirement profiles for A. baremoze were found to be similar to those observed in other omnivorous fish species. Considering the importance of A. baremoze as a potential species for freshwater aquaculture, the present data provides guidance to the development of test diets with appropriate amino acid inclusions until dose response treatments are carried out.
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    Nutrient composition of fish protein powder developed from Brycinus nurse (Rüppell, 1832)
    (Food Science & Nutrition, 2018) Kasozi, Nasser; Asizua, Denis; Iwe, Gerald; Namulawa, Victoria T.
    A new product in the form of edible fish powder was developed from small pelagic fish (Brycinus nurse) which constitutes one of the major commercial fisheries in Lake Albert, Uganda. The objective of the study was to determine the proximate and mineral composition of the newly developed fish powder and also to compare it with Nile tilapia powder already on market. Results indicated that the changes in the amount of protein and ash were found to be significantly higher (p < 0.05) in fish powder than in fried samples. The increase in fat content of fried fish samples was found to be significant compared to other fish samples. No significant changes (p > 0.05) were observed in carbohydrate content for raw, fried, and powdered samples. Vitamin A decreased significantly in powdered samples. Comparing the B. nurse powder and tilapia powder (made from juvenile tilapia as raw material), the results indicated that B. nurse had higher levels of iron and manganese. Extracting proteins from B. nurse provides an opportunity to increase the utilization of harvested catch.
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    Site suitability assessment of selected bays along the Albert Nile for Cage Aquaculture in West Nile region of Uganda
    (International Journal of Fisheries and Aquaculture, 2016) Kasozi, Nasser; Opie, Hellen; Iwe, Gerald; Enima, Christopher; Nkambo, Mujibu; Turyashemererwa, Martin; Naluwayiro, Janet; Sadik, Kassim
    Selection and management of sites are among the most significant elements for the success and sustainability of aquaculture operations. Water quality, water depth and water current are three of the major factors that need to be considered before initiating cage culture in a natural water body. This study was conducted to identify suitable sites for cage farming along the Albert Nile of Uganda by assessing the physical, chemical and topographical characteristics over a three month period. Four bays (Odoi, Fundo, Onere and Isirini) were randomly sampled and the results were compared against the acceptable standards. Basing on the physical and chemical criteria, most of the surveyed points were within the acceptable ranges except for the water depths which were lower and total suspended solids which were higher than the recommended ranges. Regarding topographical characteristics, Odoi and Fundo bays were found to be very prone to floating weeds and submergent macrophytes. All the sampled areas within Odoi, Fundo and Onere fishing bays whose depths were found to be more than 2 m can be manipulated to have Low Volume High Density (LVHD) cages while Isirini, Acaar and Ayilebe fishing bays were found not to be suitable for cage culture because they were very shallow.