Table 1 Optimum dietary nutritional requirement of freshwater crayfish and its comparison with NRC (2011) standards for penaeid shrimps (usually adopted as status quo).
Parameter | Crayfish standard (calculated) | NRC4 standards for penaeid shrimps |
|---|---|---|
Macronutrient and energy (based on Cherax sp. and Procambarus sp.)—crude | ||
Crude protein | 29–34% (44%)* | 33–42%** |
Crude lipid | 6.5–9% | 5–6% |
Crude NFE (nitrogen-free extract) | 40–47% | – |
Dietary fiber | Up to 7% | – |
Total ash | 7.8–10.8% | – |
Gross energy | 3590–4205 kcal kg−1 | 3666–4888 kcal kg−1** |
Protein: Energy | 72–91 mg kcal−1 (113–119 mg kcal−1)* | 85–90 mg kcal−1 |
Non-protein energy: Protein ratio | 5.3–8.5 cal mg−1 (4.4–4.8 cal mg−1)* | – |
Essential amino acids (based on P. clarkii only)—digestible | ||
Leucine | 1.8–2.5% | 1.8% |
Valine | 1.2–1.6% | 1.4% |
Threonine | 0.3–1.5% | 1.3% |
Isoleucine | 1.2–1.7% | 1.2% |
Arginine | 2.1–2.7% | 1.8% |
Phenylalanine | 0.8–1.5% | 1.4% |
Lysine | 1.2–2.4% | 1.8% |
Methionine | 1.1–4.9% | 0.7% |
Histidine | 0.6–0.9% | 0.7% |
Tryptophan | 0.4% | – |
Essential minerals (based on Astacus sp., Ornectes sp., and Procambarus sp.)—available | ||
Calcium | 3000–4000 mg kg−1 | – |
Phosphorus | 164–235 mg kg−1 | 3000–7000 mg kg−1 |
Iron | 27–125 mg kg−1 | – |
Zinc | 10–14 mg kg−1 | 15 mg kg−1 |
Copper | 6–9 mg kg−1 | 10–32 mg kg−1 |
Manganese | 14.2–17.8 mg kg−1 | – |
