Effect of Drying Methods on the Nutritive Value of Some Aquatic Macrophytes in River Rima, North Western Nigeria

A comparative study on the effectiveness of different drying methods on the nutrient contents of water hyacinth (Eichorniacrassipes) , Water lilly(Nymphae lotus) and water primrose (Ludwigiahysopifollia ) leavewas carried out in order to ascertain their potential as nutrient supplements in fish feed formulation. Whole components of each plant were weighted and 600g each of the leave were separately weighted in triplicates and was subjected to oven dying, sun drying and air drying. Results of analysis indicated that oven dried leave of Ludwigiahysopifolliahad significant (p< 0.05) high crude protein (15.13± 0.01) than sun dried and air dried (11.64±0.01 and 4.84±0.60), this follows the same trend with Eichorniacrassipes and Nymphaea lotus 12.52± 0.12 and with 11.76 ± 0.02 respectively. The ash, crude fiber and crude lipid contents exhibit no significant (p> 0.05) difference in the oven drying method of the three plants. Moisture content differ significantly (p< 0.05) in Eichorniacrassipes in all the drying methods, higher values Nitrogen Free Extract was recorded in each drying method. The percentage composition of leaves shows that Ludwigiahysopifollia has 64.74% Eichorniacrassipes has 16.01% and Nymphea lotus 55.95%. The study concluded that oven drying recorded the best effect on the nutrients contents of the plant leaves this grossly followed by air and sun drying method, and also the leaves of these macrophytes can be used to substitute conventional carbohydrate not protein supplements in fish feeds. Further studies should be carried to assess the potential of these macrophytes subjected to the various drying methods in feeding cultured fish species.