Browsing by Author "Mwandya, A.W"

Now showing 1 - 2 of 2

Comparative analysis of physical post-harvest losses of rastrineobola argentae dried using various drying methods along lake Victoria, Tanzania
(2022) Mhanga, S.F; Mwandya, A.W
Rastrineobola argentae (Dagaa) has been the major commercial fishery of Lake Victoria contributing 67.4 % of total fish catch. In Tanzania it constitutes over 38% of the total fish landings from the Lake. However, there is a high level of post-harvest loss of about 59%. To minimize the losses, various post-harvest innovations processing methods have been developed in previous studies, but still there is limited empirical evidences showing the effectiveness of these innovations to justify their adoption. In the present study, a completely randomised experimental design was conducted to determine the effect of three drying methods of dagaa namely, solar tent, bare sand, and raised racks in reduction of physical post-harvest losses of dagaa in Mwanza, Lake Victoria. Data were collected by simple random sampling of dagaa from boats, key informant interviews and desk review of secondary data. The results showed that solar tent reduced post-harvest losses up to 24.9% compared to raised racks (14.9%) and bare sand (10%). The results showed significance differences (p<0.00), whereby the differences were noted between solar tent with raised racks (p=0.02) and between solar tents with bare sand (p=0.00) only. Based on the findings the study recommends that solar tent innovation should be promoted to commercial scale to contribute in reducing dagaa post-harvest losses. The reduction of post-harvest losses implies more quantities of dagaa will be available for nutrition and income.
Production of freshwater infusoria and blacksoldier fly larvae using various organic substrates as starter feeds for fish larvae
(An International Journal of Basic and Applied Research, 2022) Mwandya, A.W; Said, J.A
Freshwater infusoria were raised on banana peels, potato peels, cabbage leaves and water lettuce for three weeks while Blacksoldier fry larvae (BSFL) raised on goat, pig and cow dung manures for four weeks was later fed to juvenile Nile tilapia as started feeds. Infusoria and BSFL were cultured in twelve plastic containers each 40 liter and nine plastic plates each 0.135 m 2 respectively. The density and biomass of infusoria; and water quality parameters were measured. The biomass and abundance of BSFL were determined. The growth performance and survival rates of Nile Tilapia (Oreochromis niloticus) were studied at three inclusion levels of BSFL (25, 75 and 100%) and fed twice a day in twelve polyethene tanks 20 litre each for two months. The mean density and biomass of infusoria were higher in banana peels and lowest in water lettuce leaves, at water temperature ranging from 21.5 ± 0.3 to 22.5 ± 0.5°C. Turbidity was generally highest in Lettuce leaves and lowest in Banana peels. Freshwater infusoria were active within 15 days of the experiment and became inactive with increasing turbidity. The biomass and abundance of BSFL were higher in pig manure and lowest in goat manure, and showed significant differences among inclusion levels (p<0.05). The growth rate of juvenile tilapia was numerically higher in treatment receiving 100% of BSFL (6.63±1.67 g) and lowest at 25% (1.92±31.11g) of BSFL. Results suggest potential of banana peels and pig manure as good substrate and higher inclusion level of BSFL to grow Nile tilapia