Prototype production of formulate feed for small scale mud crab aquaculture

Abstract

Since crab formulated feeds are limited in the market, small scale production with simple and adjustable processes would be an ideal solution for developing crab aquaculture. Herein we described the prototype for formulate feed production that was composed of shrimp formulate feed (42.5%) mixed with binders: wheat gluten (7.5%) and alpha starch (2.5%), mashed fish meat (5%) and Kale powder (2.5%). The mixture was then reformed into pellets using household mincer and dried at 60^oC for 2 hr. The pellets can be stored at room temperature for 1 week. Proximate analysis, stability, ingestion assay, and the worthiness of the feed were determined in comparison with commercial feed. The results revealed that the main nutrition values including protein, lipid and carbohydrate of prototype feed were 40.08±0.14%, 5.3±0.04%, 27.14%, respectively, whereas those of the commercial are found at 39.63±0.08%, 12.19±0.24%, and 27.37%, respectively. The stability between both feeds were significantly observed after 2 hr (89.35±1.54% in prototype and 80.49±2.74% in commercial feed) and 3 hr (78.17±0.41% in prototype and 73.06±2.22% in commercial feed) while the first hour was similar.  It was found that the prototype pellet attracted crab better than the commercial one (86.67% and 60.00% (n=15), respectively).  Palatability of the prototype pellets was 64.10% compared to that of the commercial diet (10.83%, P<0.05). When production cost per round is considered, prototype production costed around 3 Satang/pellet (~0.4 g/pellet), and it required 3 pellets to feed in similar amount with commercial pellet. Therefore, per each meal, prototype feed costed lower than the commercial one (8 and 12 Satang, respectively). According to this study, the prototype feed offers simpler and more flexible use for small scale production, and allows mud crab farmers to design their own feed formula.