EFFECT OF INSECTICIDE RESIDUE ON NUTRITIONAL QUALITY OF COWPEA (Vigna unguiculata L. Walp) HAY

Abstract

This study was conducted to evaluate the effect of pesticide residues on the chemical composition of cowpea (Vigna unguiculata) fodder used as livestock feed. Cowpea was cultivated in two separate plots (P1 and P2). In P1, synthetic chemicals were applied for land clearing, weed management and pest control, whereas P2 was managed using manual land clearing, hoe weeding and neem extract was used as natural pest control agent. After harvesting and shade drying, the leaves, stems and roots from P1 were sampled and analysed to determine pesticide residues as well as proximate and mineral compositions using standard laboratory procedures. Data generated were analysed using SAS and treatment means were separated at P < 0.05 using LSD. Pesticide residue analysis showed that the leaves accumulated the highest concentrations of residues, particularly atrazine (0.88 mg/kg) and carbaryl (0.81 mg/kg). Chemical analysis indicated that the leaf portion was nutritionally superior to the stem and root fractions in both Plots 1 and 2. In contrast, mineral analysis showed that the root fraction consistently contained the highest concentrations of Zn, Fe, Mg, and K across both plots. It is concluded that the leaf portion despite being nutrient-dense also accumulated the highest concentrations of chemical residues, suggesting potential health risks for livestock. Therefore, farmers are recommended to adopt natural pest control agents such as neem extract, which pose minimal risks to feed quality, environmental safety and animal health compared to synthetic pesticides.