Growth of market-size abalone (Haliotis midae) fed kelp (Ecklonia maxima) versus a low-protein commercial feed

Abstract

The growth of grow-out abalone fed on kelp, with ca. 10 % dry weight protein content, was compared with that of those fed a new ,ca. 26 % protein, commercial feed in a flow-through system on a South African west coast commercial abalone farm. While both feeds produced similar gains in shell length (45.220 μm.day-1 for kelp, 46.839 μm.day-1 for commercial feed), the latter significantly outperformed kelp in terms of weight gain (0.266 % body weight.day-1 for commercial feed; 0.257 % body weight.day-1 for kelp). This low-protein commercial feed may prove to be of considerable benefit as substitute for the kelp plus high-protein feed sometimes used for abalone, because it has most of the benefits of the two feeds, but none of their apparent disadvantages.