Browsing by Author "Magana, A."

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Carcass Fatty Acid Composition and Sensory Properties of Nile Tilapia (Oreochromis Niloticus) Fed on Oilseed Meals With Crude Papain Enzyme
(East African Journal of Science, Technology and Innovation, 2022) Kirimi, J. G.; Musalia, L. M.; Munguti, J. M.; Magana, A.
In this study, proximate body composition, fillets fatty acid and sensory properties of Nile tilapia fed on oilseed meals with crude papain enzyme were determined. A control diet (D1) of 300g/kg crude protein (CP) and (2900Kcal/kg) was formulated using fishmeal (Rastrionaebola argentea) (FM) and test diets by replacing 10% CP of FM by soybean meal (SBM) (D2), canola meal (CM) (D3) and sunflower meal (SFM) (D4). One hundred and one days feeding trial was conducted in a 4x2 factorial design on 4 diets (D1, D2, D3 and D4) with (0.06%) and (0%) enzyme using 720 Nile tilapia fingerlings (7±3g). Fish were fed twice daily at 5% of their biomass at 10am and 4pm in two equal meals. At the end of feeding trial, fish were starved for 24 hrs and weighed. A sample of ten fish representing the average weight of each replicated group was used. The fillets fatty acid profiles were determined by MPA FT-NIR spectrometer. Organoleptic tests of both fresh and steamed fish were carried out by eight semi trained panellists using 5-point hedonic scale. There was increase (p<0.05) in carcass proximate composition in all the treatments. Fillets fatty acid levels were influenced by the crude papain enzyme (p<0.05). Palmitic acid (C16:0), linoleic acid (C18:2n-6) and oleic acid (C18:1n-9) were the most abundant fatty acids in the fillets. Fish fed on fishmeal based diet recorded higher percentage (22.56) of polyunsaturated fatty acids (PUFA). There was significant difference among the treatments (p<0.05) for general appearance. Fish fed on crude papain enzyme treated diets were less preferred. It is recommended that more research be done on the effect of papain enzyme on the carcass fatty acid and sensory properties of farmed fish.
Effect of Substituting Fishmeal with Oilseed Meals on Diets Fatty Acid and Proximate Composition for Nile tilapia (Oreochromis niloticus)
(Journal of Agriculture and Veterinary Science, 2021) Kirimi, J. G.; Musalia, L. M.; Munguti, J. M.; Magana, A.
The study aimed to evaluate the fatty acid and proximate composition of diets for Nile tilapia containing soybean meal (SBM), canola meal (CM) and sunflower meal (SFM) as replacements of fishmeal (FM). A control diet (D1) of 30% crude protein (CP) was formulated using fishmeal as main protein source. The test diets (D2, D3 and D4) were formulated by replacing 10% CP of FM by SBM, CM and SFM, respectively. The fatty acid profile of ingredients and diets were determined by MPA FT-NIR spectrometer. FM displayed higher CP content (62.60%) followed by SBM (47.38%), CM (34.39%) and SFM (24.81%). SFM had highest crude fibre content (p<0.05) while CM displayed higher figure for ether extracts (p<0.05). Substituting FM with SBM, CM and SFM increased the levels of crude fibre (p<0.05). Diet 4 recorded highest crude fibre (16.03%) content (p<0.05), while CM based diet recorded highest ether extract content (10.75%), (p<0.05). Diet 1 had lowest concentration (21.85mg/100g) of total saturated fatty acid and D2 lowest concentration of polyunsaturated fatty acid (29.90mg/100g). The study revealed that 10% CP substitution of FM with SBM, CM and SFM in Nile tilapia diets is possible without much negative change in diets proximate and fatty acid composition.
Effect of Substituting Fishmeal with Oilseed Meals on Diets Fatty AcidandProximate Composition for Nile tilapia (Oreochromis niloticus)
(IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS), 2021-09) Karimi, J.G.; Musalia, L.M.; Munguti, J.M.; Magana, A.
The study aimed to evaluate the fatty acid and proximate composition of diets for Nile tilapia containing soybean meal (SBM), canola meal (CM) and sunflower meal (SFM) as replacements of fishmeal (FM). A control diet (D1) of 30% crude protein (CP) was formulated using fishmeal as main protein source. The test diets (D2, D3 and D4) were formulated by replacing 10% CP of FM by SBM, CM and SFM, respectively. The fatty acid profile of ingredients and diets were determined by MPA FT-NIR spectrometer. FM displayed higher CP content (62.60%) followed by SBM (47.38%), CM (34.39%) and SFM (24.81%). SFM had highest crude fibre content (p<0.05) while CM displayed higher figure for ether extracts (p<0.05). Substituting FM with SBM, CM and SFM increased the levels of crude fibre (p<0.05). Diet 4 recorded highest crude fibre (16.03%) content (p<0.05), while CM based diet recorded highest ether extract content (10.75%), (p<0.05). Diet 1 had lowest concentration (21.85mg/100g) of total saturated fatty acid and D2 lowest concentration of polyunsaturated fatty acid (29.90mg/100g). The study revealed that 10% CP substitution of FM with SBM, CM and SFM in Nile tilapia diets is possible without much negative change in diets proximate and fatty acid composition. Key words: Crude protein, Essential fatty acids, Nile tilapia, Nutrients composition
Factors Influencing Adoption of Pigeon Pea and its Impact on Household Food Security in Machakos County, Kenya
(Asian Journal of Agricultural Extension, Economics & Sociology, 2022) Emongor, R. A.; Matiri, F. M.; Magana, A.; Wamaitha, J.; Daniel, A. M.; Mulindo, J.; ; ;
A household survey was carried out in Kalama, Mwala and Yatta Sub-counties of MachakosCounty Kenya to obtain data on the current situation of pigeon pea value chain. A total of 414households were interviewed in the month of October 2020. Data was analysed using descriptivestatistics, Logit Model to determine factors that influence adoption of pigeon pea ( Cajanus cajan L)using Statistical Package for Social Scientists (SPSS) version 20 Software. The HFIAS model wasused to determine the impact of adoption of Pigeon Pea on household food security. The results ofthe descriptive statistics showed that there was low adoption of the Pigeon pea technologies andthis implies that more needs to be done in creating awareness of the improved Pigeon peavarieties. The Logistic model results showed two factors that significantly influence adoption of Original Research Article
Screening of Plant Extracts Possessing Methylenedioxyphenyl (MDP) Group as Potential Synergists in Insecticide Formulations using the Maize Weevil, Sitophilus Zea-mais (Motsch.)
(Merit Research Journals, 2020) Michura, A.J.G; Magana, A.; Ombaka, O.; Gachoka, K.
Synergists are compounds that are either negligibly toxic or non-toxic to insects when applied on their own, but enhance the efficacy of an insecticide. Many insects are able to detoxify insecticide molecules and survive their application. Early studies found that most methylene-dioxyphenyl (MDP) agents themselves possess relatively low intrinsic toxicity, but strongly influence the actions of other xenobiotic in mammals and insects. The current commercial synergist, Piperonyl butoxide (PBO), though effective as a synergist, is not classified as an organic product in many countries. With the current focus on decreasing environmental contamination and increasing demand for organic products, a natural compound for use as a synergist would be ideal. Searches for effective synergists have not yet yielded many compounds that have the viability equivalent to that of PBO. This paper screened plant extracts possessing MDP rings as potential synergists in insecticides formulations using the maize weevil, Sitophilus zea-mais. Dose-mortality experiments were carried out on S. zea-mais at four concentrations of synergists. Topical application of synergist on S. zea-mais was done in triplicate in a CRD. Experiments were conducted under controlled laboratory conditions of 27 ± 2OC and 60 ± 5%RH with normal daylight hours. Analysis of Variance (ANOVA) was used to obtain the mean mortality differences of S. zea-mais at P ≤ 0.05 while Duncan’s Multiple Range Test (DMRT) was used to rank significant concentration means within a synergist. Black pepper seed hexane extract (BPSHE) and PBO after 48 h exposure were statistically significant (P ≤ 0.05) with the average percentage mortalities of 10% and 20% at 10,000 ppm and 20,000 ppm respectively, while PBO and Coriander leaves hexane extract (CLHE) were significant P ≤ 0.05 after 72 h. PBO was the most toxic synergist (36.67 ± 3.33%) followed by CLHE (26.67 ± 3.43%) at 20,000 ppm. It can be concluded that the plant extracts tested and statistically significant at a particular exposure time can be used to replace the standard PBO in insecticide formulations since their inherent toxicity is low. At a higher concentration (20,000 ppm) PBO was the most toxic synergist which could be contributing to the toxicity of insecticide when used in formulations.