8. ESSENTIAL NUTRIENTS - RECOMMENDED NUTRIENT SPECIFICATIONS FOR COMPLETE DIETS

8.1 Introduction

At present little or no information is available concerning the quantitative dietary nutrient requirements of fish or shrimp under semi-intensive pond rearing conditions, or regarding the nutrient requirements of the first-feeding larvae and broodstock of fish or shrimp under intensive culture conditions. Despite this, and on the basis of the ‘laboratory based’ nutritional feeding trials conducted to date, some generalized conclusions may be drawn regarding the recommended nutrient levels within practical feeds intended for use within intensive ‘clear water’ aquaculture systems (ie. aquaculture culture systems such as cement tanks or raceways, and cages suspended in clear open water bodies). At present it is not possible to give dietary nutrient recommendations for feeds intended for use within semi-intensive aquaculture culture systems such as earthen ponds; the dietary nutrient requirements of fish or shrimp within these culture conditions depending on aquaculture species, species stocking density, the fertility of the water body, and the availability of natural pond food organisms.

8.2 Fish

Table 15 and 16 presents the dietary nutrient levels recommended for carnivorous and omnivorous fish species respectively. With the exception of the dietary lipid sources, the nutrient levels indicated apply equally for both freshwater and marine fish species.

8.3 Shrimp

Table 17 and 18 presents the dietary nutrient levels recommended for carnivorous and omnivorous shrimp species. In the absence of quantitative information on the dietary mineral and vitamin requirements of shrimp, the dietary levels recommended are generally based on the known dietary vitamin and mineral requirements of fish. In addition, until further information is available concerning the dietary nutrient requirements of freshwater prawns, the nutrient levels recommended for omnivorous marine shrimp (Table 18) should be initially adopted as a tentative guideline for freshwater prawns.

¹ Dietary nutrient levels recommended for clear-water ‘intensive’ aquaculture systems (ie. tanks, cages, raceways)

² Fish size class: fry 0–0.5g; fingerling 0.5–10g; juvenile 10–50g; grower 50g+; brood fish 1kg+ (varies with species)

³ For strict marine carnivorous fish species plant lipid can be omitted from the farmulation

⁴ Amino acid requirement based on carcass essential amino acid pattern of whole fish tissue (Wilson & Cowey; Table 4)

⁵ Suggested minimum dietary vitamin levels required to prevent deficiency signs. Values in parentheses indicatesuggested dietary vitamin levels taking into account processing, storage and leaching losses

⁶ These vitamins should be added separately to the diet and not included in the form of a multivitamin premix;vitamin C should be added in fat coated form so as to minimise losses through diet processing and leaching

¹ Dietary nutrient levels recommended for clear-water ‘intensive’ aquaculture systems (ie. tanks, cages, raceways)

² Fish size class: fry 0–0.5g; fingerling 0.5–10g; juvenile 10–50g; grower 50g+; brood fish 1kg+ (varies with species)

³ Equal proportions of plant and fish oil should be used so as to satisfy essential fatty acid requirements

⁴ Amino acid requirement based on carcass essential amino acid pattern of whole fish tissue (see Table 4)

⁵ Suggested minimum dietary vitamin levels required to prevent deficiency signs. Values in parentheses indicatesuggested dietary vitamin levels taking into account processing, storage and leaching losses

⁶ These vitamins should be added separately to the diet and not included in the form of a multivitamin premix;vitamin C should be added in fat coated form so as to minimise losses through diet processing and leaching

¹ Dietary nutrient levels recommended for clear-water ‘intensive’ aquaculture systems (ie. tanks, cages and raceways)

² Shrimp size class: Larval - protozoea substage 1 to post-larval substage 1 (PLI); PLI to PL25 (25 days from PLI);PL25 to lg; juvenile - 1g to 10g; grower - 10g to harvest; broodstock - 10g+

³ Marine lipid includes shrimp head oil, marine fish body oil, marine fish liver oil, or marine invertebrate oils.So as to satisfy a possible dietary phospholipid requirement, a concentrated source of phospholipid should be addedin the form of soybean oil or a soy-lecithin preparation

⁴ Cholesterol can be added either in purified form or by using dietary lipid sources naturally rich in cholesterol suchas shrimp head oil

⁵ Amino acid requirement based on the carcass essential amino acid pattern of the short-necked clam (Table 4)

⁶ Maximum limit refers only to crude fibre of plant origin, and excludes crude fibre derived from shrimp meal (ie. chitin)

⁷ Suggested minimum dietary vitamin levels required to prevent deficiency signs. Values in parentheses indicate suggesteddietary vitamin levels taking into account processing, storage and leaching losses; the latter being 2 to 5 timesgreater than the recommended dietary requirements due to the extremely slow and extended feeding habits of marineshrimp, and to compensate for the considerable losses of vitamins which occur through leaching. However, the actualmultiplication factor used should be adjusted in situ (ie. either higher or lower) depending on the water stabilityof the diet and the feeding response of the shrimp to the diet, and finally on the time period the feed remains inthe water before total consumption

¹–⁶ as in Table 17