Uganda Journal of Agricultural Science (UJAS)
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Dietary Fishmeal Substitution by Peanut-Based Meals in Nile Tilapia (Oreochromis Niloticus L.) : Effect of Pond Water Quality on Biomass Production: Effect of Pond Water Quality on Biomass Production
No full textAbstract. A 16 week experiment was conducted in earthen ponds in Iganga District of Eastern Uganda to investigate the effect of water quality on biomass production in Nile tilapia (Oreochromis niloticus L.) fed on peanut-based meals as alternative dietary fishmeal. Iso-nitrogenous diets containing 30% and 25% Crude Protein were applied for the first 12 weeks and last four weeks while the control was a local diet for Nile tilapia of 25% Crude Protein throughout the experiment. Treatments included the fishmeal-based diet and two peanut-based diets; peanut meal-based diet and mixed meal-based diet. Each of the 16 pond units measuring 3.0 x 4.0 x 1.0 were stocked with 48 fish fingerlings of 21.7 grams mean weight. Significant differences (p≤0.05) in mean values occurred among targeted parameters; pH, Dissolved Oxygen, nitrite nitrogen and unionized ammonia with exception to temperature. Apart from the unionized ammonia, the significant variations (p≤0.05) in water quality parameters did not significantly affect (p≥0.05) biomass production because they were maintained in suitable ranges for Nile tilapia
Profit Indices in Nile tilapia (Oreochromis Niloticus L.) Fed on Peanut-Based Meals as Alternatives to Dietary Fishmeal in GrowOut Earthen Ponds
Get PDFPersistence of dietary fishmeal probably accounts for the low profitability in farmed Niletilapia in Uganda. A 24 week field study was conducted in Busoga sub-region of Eastern Uganda tocompare profit indices in pond cultured Nile tilapia fed on peanut-based meals as alternatives todietary fishmeal. It consisted of an experiment and sample survey that targeted fish biomassproduction and input-output valuation respectively. Each of the 12 earthen ponds measuring 12 cubicmeters were stocked with 48 ‘all male’ Nile tilapia (Oreochromis niloticus L.) fingerlings of meaninitial weight of 21.7 grams. Iso-nitrogenous diets containing 30% and 25% Crude Protein wereapplied for the first eight and last four respectively. Dietary treatments included fishmeal-based dietand two peanut-based diets; peanut meal-based diet and mixed plant-based diet. Profit indices for thefishmeal and mixed plant-based- diets were not significantly different (p0.05). On the contrary, theProfit index characteristic to the PNM-based diet was significantly lower (p≤0.05) than the other testdiets. Accordingly, the mixed plant meal should be used for complete substitution of dietary fishmealin pond cultured Nile tilapia
Situation of ticks and seroprevalence of Theileria parva in two farming systems in Nakaseke and Nakasongola districts of Uganda
Get PDFThis study delved into the composition of ticks, prevalence of Theileria parva and management of East Coast Fever in Nakaseke and Nakasongola districts of Uganda. The tick challenge on animals was assessed and whole blood was collected for determination of seroprevalence of Theileria parva using Enzyme-Linked Immunosorbent Assay. Majority (82.3 percent) of the cattle were found to be infested with Rhipicephalus appendiculatus (88.2 percent), Ambryomma variegatum (7.5 percent) and Rhipicephalus evertsi (4.3 percent). Majority (80.7 percent) of the respondents believed that tick infestation was severe and regularly managed using acaricides (65.3 percent). In the pastoral farming system, no ticks were found on calves below 6 months of age. In the mixed crop-livestock farming system, all cattle age groups were exposed to the ticks. The seroprevalence of T. parva varied among age groups of cattle in both farming systems. There was moderate correlation between the mean number of R. appendiculatus ticks and seroprevalence of T. parva (r = 0.47). Association was established between mean number of ticks and farming system (p = 0.019) and percentage positivity of T. parva and farming system (p = 0.007). Theileria parva was prevalent in the two farming systems despite frequent application of acaricides. Thus, the study provides evidence of the tick-borne disease pathogens and vectors responsible for ECF, R. appendiculatus being the principal tick species infesting cattle in the area. Creation of community-based technical and advisory services for livestock health management is recommended
Potential Impacts of Oil and Grease on Algae, Invertebrates and Fish in the Bujagali Hydropower Project Area
Get PDF. This study determined the concentration of oil and grease and inferred its impacts on algae,invertebrates and fish. Water samples were collected in April and September from 2012 to 2018 atthe upstream and downstream transects and in the reservoir, and analysed for oil and grease followingstandard procedures. Environmental compliance was compared to NEMA’s discharge standard of 10mg/l, and its PAH effluent discharge standard of ≤ 0.1 mg/l. At all sites, average concentrations ofoil and grease were below 10 mg/l throughout the sampling period. Out of the 14 data sets for eachtransect, only 3 along the upstream transect, and 2 at each of the downstream transect and the reservoirwere compliant with the effluent discharge standard. Although impacts of oil and grease on aquaticbiota were not assessed, their relatively high concentration compared to total Polycyclic AromaticHydrocarbon (> 0.1 µg/l) is considered hazardous to most aquatic organisms. The diverse activitiesaround the project area implied that sources of oil and grease were proportionately diverse. Hence,the observed trends may not solely be attributed to the hydropower project. Accordingly, assessmentof the various sources of oil and grease and their impact on aquatic biota in the area is recommended
Distributional Patterns of Gastropoda Upstream and Downstream of Bujagali Hydropower Project along the Upper Victoria Nile
Get PDFAbstract. To better understand the gastropod community dynamics of fresh water snails in the Upper Victoria Nile (UVN), the spatial and temporal abundance changes in gastropod assemblage were assessed biannually from April 2006 to April 2021 at three transects. Biannual abundances of gastropoda were obtained by a ponar grab to examine changes in their community structure in relation to Bujagali Hydropower Project (BHP). The gastropod community consisted of nine species belonging to five families (Thiaridae, Viviparidae, Ampullariidae, Bithyniidae and Planorbidae).Pulmonate species registered five species (Anisus natalensis, Gyraulus sp., Segmentorbis sp., Bulinus sp. and Biomphalaria chaonomphola). Two of the pulmonates (Bulinus sp. and B. chaonomphala)are schistomiasis vectors. The pulmonates (A. natalensis, Gyraulus sp., Segmentorbis sp.) were rare and intermittently occurred with abundances up to 47 ind.m-2. Four prosobranch species (Gabbia humerosa, Pila ovata, Melanoides tuberculata and Bellamya unicolor) were encountered. Of these prosobranchs, P. ovata was the rarest while M. tuberculata and B. unicolor were the commonest. The gastropod community in the UVN was characterised by prosobranchs-dominated abundance which over the 16-year monitoring period often registered peak densities of > 1000 ind.m2. The inter-site Percent Similarity Index (PSI) (94-100%) indicated a high degree of similarity of gastropod community across the sites
NIRS Predictions, Phenotypic Variability and Optimization of Cooking Time for Evaluation of the Root Softness of Boiled Cassava
Get PDFThis study aimed at quantifying the extent of genetic variability of softness in cassava germplasm across varied cooking times and root sections. It also examined the possibility of using Near Infrared Spectroscopy (NIRS) for measurement of cassava root softness. Softness was evaluated using a penetrometer. This was done at 15, 30 and 45minutes cooking time, all across proximal, middle and distal root sections. These measurements were done on 57 accessions. For each sample, spectra were acquired using NIRS Benchtop (FOSS DS2500) on a composite of each root section of mashed fresh cassava sample. Modified Partial Least Squares regression (MPLS) was used for NIRS calibration development using WINISI software. Significant (P < 0.001) variability in softness was established. Cooking time significantly influenced softness and there were significant accession and root part interaction (P < 0.001). Wide variability and high heritability (H = 0.8) were found for softness at 30 minutes cooking time. Highest association was found with 30- and 45-minutes cooking time (r = 0.58). Strong association was observed between middle root section with distal (r = 0.74) and proximal (r = 0.73). NIRS softness calibration (R2c) were 0.445, 0.413 and 0.521 for 15-, 30-, and 45-minutes cooking time respectively. NIRS prediction (R2p) were 0.322, 0.192, and 0.390 for 15-, 30-, and 45-minutes cooking time respectively. These results suggest that 30 minutes cooking time and middle root section are optimum for softness phenotyping
Drought Stress and Adaptation Strategies in Kumi and Amuria Districts of Uganda
Get PDFAbstract. This study investigated smallholder farmers’ drought adaptation strategies in 246 randomly selected households in Kumi and Amuria districts of Teso sub region of Uganda. Primary and secondary data were collected, the former through individual interviews, focus group discussions and key informant interview and the latter through document review. The results revealed that drought stress was above -4 kilo pascal within the period 2006–2016. The adaptation strategies applied included cultivation of food crops that can be preserved and offering of labour on other people’s farms as a survival strategy. Promotion of early warning mechanisms; easy access to farm inputs;group formation and consolidation; and affordable irrigation technology are recommended to enhance farmers’ resilience
Effect of Phosphorus-Based Fertilizer on Groundnut Yield and Incidence of Groundnut Rosette Disease in West Nile Region of Uganda
Get PDFThe objective of this study was to establish the effects of Di-ammonium phosphate (DAP) fertilizer micro-dosing on yields and the incidence of groundnut rosette disease (GRD) on five groundnut varieties in West Nile region of Uganda. The field experimental design used in this study was 5x2 factorial laid in a randomized complete block design (RCBD) with three replicates per location across 6 locations. The results indicated that there were significant (p = 0.05) differences in groundnuts yields across locations and varieties (0.554 – 1.742 tons per hectare) with or without micro-dosing with DAP fertilizer. The effects of DAP fertilizer micro-dosing in groundnut production were twofold: increase in yields across locations from 427.27kg/acre with no micro-dosing to 525.73kg/acre with micro-dosing (23.04% increment) and varieties from 420.46kg/acre with no micro-dosing to 529.71kg/acre with micro-dosing (13.77% increment); and a reduction of groundnut rosette virus disease incidence across locations from 15.13% with no micro-dosing to 11.20 with micro-dosing (27.76% reduction) and on varieties from 15.08% with no micro-dosing to 11.82% with micro-dosing (34.62% reduction). This is the first report of a prospective DAP fertilizer micro-dosing alongside other improved agronomic practices which can be integrated fully into groundnut production in West Nile region of Uganda. To manage yields and GRD incidences, micro-dosing of crops should be taken as a climate smart technology as identified by Food and Agricultural Organization
Effect of Spent Mushroom Substrate and NPK Fertilizer on White and Orange-Fleshed Sweet Potato Varieties in South Eastern Nigeria
Get PDFSpent mushroom substrate (SMS) and NPK (15:15:15) fertilizer were assessed under field conditions for their comparative effects on white and orange-fleshed sweet potato varieties in Umuahia southeastern Nigeria. The experiment was a split-split plot in randomized complete block design with three replicates. The main plot treatments were two sweet potato varieties (white-fleshed TIS87/0087 and orange-fleshed Umuspo 3). The split plot treatments were five NPK fertilizer rates (0, 100, 200, 300 and 400kg/ha) while the split-split plot treatments were three SMS levels (0, 2 and 4t/ha). Averaged across sweet potato varieties and NPK fertilizer, SMS significantly increased leaf area index, shoot biomass and storage root yield. Application of NPK fertilizer increased leaf area index and shoot biomass in both years and storage root yield in 2019. The white-fleshed TIS87/0087 variety produced significantly higher shoot biomass than Umuspo 3 in both years. TIS87/0087 had higher root yield than Umuspo 3 in 2018, but in 2019, the latter out yielded the former. Three-way interactions were significant for shoot biomass in 2018 and for storage root yield in both years. The highest shoot biomass (28.70 – 30.0t/ha) in 2018 was obtained from TIS87/0087 at moderate rates of 2t/ha SMS and 300kg/ha NPK fertilizer and from Umuspo 3 at 2t/ha SMS and 200kg/ha NPK fertilizer. The highest storage root yield 30.0t/ha was obtained from TIS87/0087 at 4t/ha SMS alone in 2018 and 37.1t/ha yield from Umuspo 3 at 4t/ha SMS only in 2019. The results showed that 4t/ha SMS was sufficient to promote high root yields in sweet potato in the area
Increasing Farmers’ Access to Aquaculture Extension Services: Lessons from Central and Northern Uganda
Get PDF. This paper focuses on examining the modalities of extension service provision, anddetermining feasible approaches for increasing accessibility among fish farmers in Uganda. The paperdraws on a cross-sectional study involving fish farming households and extension workers todetermine access to extension services for improved farming practices. Quantitative data werecollected from 246 households using a semi-structured questionnaire. Qualitative data were generatedfrom Key Informant interviews with selected extension workers, officials in charge of extensionplanning District Fisheries Officers and Fish Farmer Group leaders. Focus Group Discussions werealso conducted with fish farmers. The results indicated a significant association between socioeconomic characteristics of fish farmers and access to extension services. Size of land owned, incomefrom pond fish and membership to fish-farmer groups were the significant factors (P<0.05). All therespondents reported pressing needs which required extension intervention. The respondentsexpressed the need to form effective farmer groups for the purpose of sharing knowledge, arriving atmutual agreement on scheduling extension activities and providing feedback to the extensionworkers. Specifically for the northern region, there is a need for the Fisheries Extension Officer toidentify and respond to the extension needs of fish farmers through various means including ICTs.Identifying solutions to social, technical and institutional constraints in extension can increase accessto services through constructive social interactions between farmers and extension agents. The articleprovides important lessons for practice and policy, and proposes a farmer-centred model, capable offacilitating increased access to aquaculture extension services in Uganda