Evaluation of fish feeder manufactured from local raw materials.

An automatic feeder for fish feeding was manufactured and evaluated successively. Feed pellet size, air flow rate and feeder screw speed were the most important factors affecting the performance and efficiency of the automatic feeder. It was tested at 3 sizes of pellets (1, 2 and 3 mm), 3 air flow rates (10, 15 and 20 m min) and 5 screw speeds (180, 360, 540, 720 and 900 rpm). The automatic feeder productivity, efficiency, specific energy consumption and costs were determined. The obtained results indicated that the automatic feeder productivity increases with increasing feed pellets size, air flow rate and rotational speed of screw treatments under study, the automatic feeder efficiency increased with increasing rotational speed of screw until it reached the highest value at 540 rpm and then remain constant at 720-900 rpm and after that decreased with increasing speed. Meanwhile, the specific energy consumption of automatic feeder decreased with increasing feed pellets size, air flow rate and rotational speed of screw treatments under study. The total cost of using automatic feeder ranged from 0.09 to 0.16 EGP kg ($ = 15.63 EGP) for all treatments under study. This feeder will save time, effort and cost for fish industry.