Evaluation of Formulated Diets Enriched by Spinach Extracts for the Broodstock Females, Portunus pelagicus (Linnaeus, 1758).

Abstract

Spinach extract (Amaranthacea tricolor) is a very prospective feed raw materials to stimulate the molting and growth of crab female broodstock. The purpose of this study was to evaluate the quality of broodstock females, Portunus pelagicus (Linnaeus, 1758) at different levels of spinach extract based on physical, organoleptic and chemical tests. Four different treatments of spinach extract (0, 250, 500 and 750 ng g-1 crab, respectively) were used in this study. The female crab samples were collected from coastal region of Padang, West Sumatera and placed randomly in four concrete tanks (200×100×100 cm). Each concrete tank consist of five units of plastic box (45.5×32.5×16.5 cm) with the maximum density was one crab per box. The organoleptic test showed that formulated diets enriched with spinach extract (0, 250 and 500 ng g-1 crab) had a smooth texture, pungent aroma and brown. Whereas from the physics test results obtained good water stability (rupture velocity ranged from 89.20-105.40 min and solids dispersion ranged from 4.97-7.17%), hardness (92.66-98.07%) and sinking velocity (3.88-5.88 cm sec-1) (p<0.05). The results also showed that formulated diet enriched with spinach extract doses of 250-750 ng g-1 crab gave a value of delicacy of feed (0.195-0.386 g crab-1 weight/day) which was significantly different (p<0.05) with 0 ng g-1 crab (0.445 g crab-1 weight/day). The chemical test shows the moisture content were 11.60%, ash 9.31%, protein 44.38%, fat 7.64% and carbohydrate 14.46%. It was concluded that there was a linear relationship between dose of spinach extracts in formulated diet and rupture velocity and a quadratic relationship between dose of spinach extracts in formulated diet and solid disperse, hardness and sinking velocity and delicacy of feed.