OPTIMAL LIPID:CARBOHYDRATE AND PROTEIN:ENERGY RATIOS IN SEMI-PURIFIED DIETS FOR JUVENILE BLACK TIGER SHRIMP PENAEUS MONODON FABRICIUS

B. Chuntapa, S. Piyatiratitivorakul, C. Nitithamyong, V. Viyakarn, P. Menasveta-1999

Aquaculture Research, 30: 825-830

Abstract:

This study aimed at determining the optimal lipid:carbohydrate and protein:energy ratios for growth and survival of juvenile Penaeus monodon Fabricius. Two experiments were performed using completely randomized designs in semi-closed recirculating water systems. Juveniles of 0.4-0.8 g in weight and 4.0-5.5 cm in length stocked at a density of 80 individuals/m^2 were fed semi-purified diets. The first experiment determined optimal lipid:carbohydrate using isonitrogenous (35%) and isocaloric (330 kcal 100/g) diets with five lipid:carbohydrate ratios: 4:39, 7:32, 9:25, 14:18 and 16:12 (% wt/wt). The lipid:carbohydrate ratio of 7:32 gave the highest growth rate (P < 0.05), while survival rates of shrimp in all other diet groups were similar but less. Thus, optimal lipid:carbohydrate ratio for the juvenile tiger shrimp was 1:4.6. In the second experiment, optimal protein:energy (P:E) ratio was studied using five protein levels (25%, 30%, 35%, 40% and 45%) with a fixed lipid:carbohydrate ratio of 1:4.6. Nine diets containing energy content (203-459 kcal 100/g) with protein:energy ratio (63-171 mg protein/kcal) were formulated. Shrimp fed the diet containing 33-44% protein and an energy content of 223-371 kcal 100/g had a significantly higher growth rate than those fed the other diets (P < 0.05). A regression analysis indicated that an optimal P:E ratio for optimal growth and survival of juvenile tiger shrimp was 150 and 146 mg protein/kcal respectively. This diet contained 33-44% protein and had optimal energy of 263-331 kcal 100/g.

(S Piyatiratitivorakul, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand)

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