Sun-drying is one way of drying moist feed to form a dry product which can be stored. Two of the problems in sun-drying are that the feed attracts flies during drying and that, in seasons when there is intermittent rain, it is difficult to complete the drying satisfactorily even though the sun is very powerful during the rest of the day.
A solar drier developed for drying fish for human consumption (Thomson, 1979) can be adapted for use for drying fish feeds. The principle is shown in Figure 1. Basically, any greenhouse type unit where convection occurs is suitable. Air should be channelled over shallow layers of feed placed on a dark surface. The scale of the drier can be adapted to the daily feed output. A clear cover which slopes to the sides as well as to one end would be better than the design illustrated in Figure 1, which is prone to leakage during rain. It is hoped that the illustration will however provoke ideas for adapting the principle involved for drying moist fish feeds for storage.
Figure 1: Solar Feed Drier