Effect of Different Drying Techniques on the Nutrients Content of Fish Feedstuffs

Abstract

The study investigated the effect of different drying techniques (air dying, oven drying and sun drying) on the proximate composition of three fish feedstuffs; Horse radish (Moringa oleifera) leaves, water lily (Pistia stratiotes) leaves and soy bean (Glysine max) seed.  The soy bean was boiled for 30 minutes at 100°C in water bath to reduce the effect of anti-nutritional factor (trypsin). Samples of each feedstuff were prepared and subjected to the three dying methods in triplicate treatments. Determination of proximate composition was carried out on the dried and fresh samples of each feedstuff. The results showed that moisture content of fresh M. oleifera  leaves (65%) and P. stratiotes leaves (85.67%)  were significantly higher (P< 0.05) than fresh G. max (2.67%). Higher crude protein content of 23.97% and 22.50% were recorded for oven-dried M. oleifera and P. stratiotes leaves and 39.21% for fresh G. max with no significant difference (P> 0.05) between the treatments. Crude lipid was significantly higher for sun dried samples of all the feedstuffs. Oven-dried samples of the three feedstuffs had the least ash, crude fiber and nitrogen free extract. The study concluded that oven drying at moderate temperature of 700C proved to be more effective in moisture removal and retention of crude protein. Furthermore, the study recommends a feeding trial to assess the potential of these feedstuffs subjected to various drying methods on growth and nutrients utilization of cultivable fish species.