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Ihegwuagu N.E.,University of South Africa | Ihegwuagu N.E.,Network-1 | Ihegwuagu N.E.,Agricultural Research Council of Nigeria | Ihegwuagu N.E.,Makurdi University Of Agriculture | And 9 more authors.
New Journal of Chemistry | Year: 2016

The facile formulation of starch-silver nanoparticle encapsulated dichlorvos and chlorpyrifos, respectively, was explored in this study with the view to develop a safer and more economical insecticide delivery system. The nanoparticle matrices were synthesized and the insecticides encapsulated in situ during the chemical reduction of silver nitrate by glucose employing direct heating. The starch-silver nanoparticle encapsulation of dichlorvos (ST-AgNP-VOS) and chlorpyrifos (ST-AgNP-FOS) was confirmed by UV-Vis spectroscopy and characterized by HR-TEM, EDX, SAED, FTIR, XRD and FESEM. The characteristic colour of AgNPs was observed and surface plasmon resonance (SPR) of the materials was found to be in the range of 418-422 nm. In addition, the XRD results revealed the silver identification diffraction peaks at 2θ angles in each formulation. The insecticide encapsulation efficiency was about 95% for ST-AgNP-VOS and 98% for ST-AgNP-FOS. Compared to control having no silver (NDVOS), both materials showed better insecticide loading. Their HR-TEM images indicated spherical natures of the materials with an average particle size range of 23-35 nm. The FESEM image showed spheres as well and a size close to that indicated by HR-TEM analysis. FTIR also confirmed the loading of dichlorvos and chlorpyrifos with additional peaks corresponding to them, compared to the insecticide-free starch. These nano-insecticide formulations were subjected to aqueous release studies. The result showed an enhanced release over the formulation without silver nanoparticles. It was concluded that this approach could be used to prepare slow release formulations of these insecticides, with the advantage of the silver nanoparticles also acting as an anti-microbial agent. This current synthetic/encapsulation process can be readily applied to large-scale production. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2016.


Shittu A.,University of Nigeria | Raji A.A.,University of Nigeria | Madugu S.A.,Agricultural Research Council of Nigeria | Hassan A.W.,University of Nigeria | Fasina F.O.,University of Pretoria
BMC Veterinary Research | Year: 2014

Background: Layer chickens are exposed to high risks of production losses and mortality with impact on farm profitability. The harsh tropical climate and severe disease outbreaks, poor biosecurity, sub-minimal vaccination and treatment protocols, poor management practices, poor chick quality, feed-associated causes, and unintended accidents oftentimes aggravate mortality and negatively affect egg production. The objectives of this study were to estimate the probability of survival and evaluate risk factors for death under different intensive housing conditions in a tropical climate, and to assess the production performance in the housing systems. Results: Daily mean mortality percentages and egg production figures were significantly lower and higher in the sealed pens and open houses (P < 0. 001) respectively. The total mean feed consumption/bird/day was similar for the open sided and sealed pens but the mean feed quantity per egg produce was significantly lower in the sealed pens ((P < 0.005). Seasons differently impacted on mortality with the hot-dry season producing significantly higher risk of mortality (61 times) and reduced egg production. Other parameters also differed except the egg production during the cold-dry season. Layers in sealed pens appear to have higher probability of survival and the Kaplan-Meir survival curves differed for each pen; ≥78 weeks old layer have higher probability of survival compared with the younger chickens and the 19-38 weeks age category are at highest risk of death (P < 0.001). The hazard-ratio for mortality of layers raised in sealed pens was 0.568 (56.8%).Conclusion: Reasons for spiked mortality in layer chickens may not always be associated with disease. Hot-dry climatic environment is associated with heat stress, waning immunity and inefficient feed usage and increase probability of death with reduced egg production; usage of environmentally controlled building in conditions where environmental temperature may rise significantly above 25°C will reduce this impact. Since younger birds (19-38 weeks) are at higher risk of death due to stress of coming into production, management changes and diseases, critical implementation of protocols that will reduce death at this precarious period becomes mandatory. Whether older chickens' better protection from death is associated with many prophylactic and metaphylactic regimen of medications/vaccination will need further investigation. © 2014 Shittu et al.; licensee BioMed Central Ltd.


Chukwumalume R.C.,Agricultural Research Council of Nigeria | Garba S.A.,Minna Federal University Of Technology | Agary O.O.,University Of Abuja
Pakistan Journal of Nutrition | Year: 2012

Microbiological assessment of preservative methods for African Star Apple juice was carried out. The juice samples were subjected to pasteurization, chemical treatment using 0.1% (v/v) sodium benzoate, a combined treatment of both or no treatment. All samples were stored in ambient (28±2°C) or refrigeration (5°C) temperatures for six weeks to determine the effect of treatments on growth count. The juice sample that was pasteurized and preserved with sodium benzoate stored longer than any other sample at both storage conditions. The combination of pasteurization, use of sodium benzoate and juice storage at refrigeration temperature gave the best storage stability. © Asian Network for Scientific Information, 2012.

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