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September | October 2011

Feature title: Feed formulation flexibility - Understanding the specific nutrient requirements of shrimp enables feed formulation flexibility in times of challenging commodity pricing

The International magazine for the aquaculture feed industry

Shrimp is one of the most important internationally-traded commodities, in terms of value and according

to the latest figures available, from the FAO (2009), world shrimp produc-tion from aquaculture represents 3.7 million tonnes per year.

It is the most valuable fishery export in many tropical developing countries provid-ing significant employment in these regions.

Feed represents more than 50 percent of the production costs of intensive shrimp production (Tan et al. 2005) with protein sources accounting for at least 30 percent of the compounds found in commercial diets.

Volatility in the availability and pricing of fishmeal, fish oil and vegetable protein sources, such as soymeal and grains etc, has encouraged flexibility in the formulation of diets to minimise cost.

This flexibility requires an in-depth understanding of the nutritional require-ment of the species and its ability to digest

and utilise nutrients from these sources, for metabolic and physiological processes.

Fishmeal has traditionally been one of the primary protein sources in shrimp diets and in addition to providing protein and essential amino acid it also serves as an attractant and provides a rich source of essential fatty acids, fat soluble nutrients and minerals.

The requirement for sustainable diets demands a reduction in fishmeal usage and its replacement by vegetable sources. A number of studies have investigated this (Forster et al. 2003, Tan et al. 2005).

However, a major concern is the incom-plete nutrient composition of these alterna-tive ingredients, which may not only reduce growth, but also increases the complexity of feed formulation as more ingredients must be utilised to satisfy nutrient requirement. This shift in formulation raises numerous concerns, such as an increase in indigestible components (fibre and non-starch polysac-charides), an increase in phytic acid (with its negative interaction on mineral availability), available phosphorous, phospholipids and general digestibility of the protein content.

As a result, cur-rent research is now focused on the effect of phytochemical components, present in these diets, on the metabolic and physi-ological response in shrimp.

In addition, the identification of genes responsible for such changes, at the molecular level, is also being investi-gated and is an area of growing impor-tance. Information

from these studies are providing further knowledge on the nutritional requirements of shrimp and enabling rapid advances in shrimp nutrition (Gillies & Faha 2003, Match et al.2005).

Proteins Shrimp, like other fish and animals, have

a requirement for a well-balanced mixture of essential and non-essential amino acids from which to construct their own protein tissues and therefore the balance of essen-tial amino acids in the diet is crucial.

The amino acid requirements of four commercially important shrimp species are shown in Figure 1

The figure indicates that the amino acid requirements of carnivorous spe-cies like P. japonicus are higher than the amino acid requirements of herbivorous species like P. vannamei. Some authors thought that their protein utilization was less effective than in the other species and therefore additional dietary protein supplementation was required. However it has been proven that the source and nature of the protein its self is important in determining the protein levels required by each species. The assimilation of amino acids by shrimps is most effective when they are bonded; as opposed to pure free essential amino acids and in this form they have performed better under the same experimental conditions.

Fatty Acids Crustaceans have long been recognized

as having a limited ability to synthesize highly unsaturated fatty acids (HUFA) de novo and having no ability to synthesize sterols de novo.

Shrimp, therefore, do not have a definitive dietary lipid requirement but rather require sufficient lipid to meet

Feed formulation flexibility

Compilation by Dr Elizabeth Sweetman

Figure 1: A comparison of the essential amino acid requirements for four shrimp species

Understanding the specific nutrient

requirements of shrimp enables feed

formulation flexibility in times of

challenging commodity pricing

32 | InternatIOnal AquAFeed | September-October 2011 September-October 2011 | InternatIOnal AquAFeed | 33

F: Formulation

IAF11.05.indd 32 02/09/2011 09:26

their requirement for specific nutrients, such as HUFA, phospholipids, sterols, and energy.

Lipids, such as phospholipids, triglycer-ides and cholesterol, are a major source of energy in shrimp diets as well as being involved in sev-eral essential processes for their growth, moulting and reproduc-tion. D’Abramo 1998 reported that changes in the temperature of shrimp culture pools may require a change in the amount of fatty acid supplementation in order to achieve established growth rates, with cold water species having a higher require-ment for HUFA than the warm water species.

Cholesterol is an essential dietary component of all animal tissues, and it plays a major role in cell membrane structure and it is a precursor for sex hormones, for bile acids and for vitamin D.

In crustaceans cholesterol is known to be the most essential dietary source of sterols as it is used for development, growth, reproduction, and survival.

It is a precursor for many hormones, including ecdyster-oids, which are critical for the initiation of metamorphosis and the moulting process (Teshima 1997). As shrimps are not capable of synthetizing cholesterol sup-plementing sterols in shrimp feed is essential.

The optimum cholesterol content of shrimp feeds will vary depending on the stage, the spe-cies and the diet composition.

Vitamins It is known that shrimps can satisfy

their vitamin requirements in natural, healthy environments from abundant micro organic life.

However, in inten-sive culture dietary vitamin supplementa-tion is essential.

Vitamin deficiency can impact on shrimp in many ways: vitamin B2 deficiency in P van-namei results in poor colouration, irritability and decreased size. Vitamin B6 deficiency can result in damage

to epithelial cells and reduced growth and muscular activity while vitamin C deficiency is characterized by poor growth, low moult-ing frequency, decreased wound healing and high mortality.

Vitamin studies have shown that the fat-soluble vitamins A, D, and E have been found to be essential in supporting shrimp growth (He et al. 1992). Dietary levels of thiamine (B1), riboflavin (B2), niacin (B3), vitamin B5, vitamin B6, choline, inositol and ascorbic acid have also been recom-mended for optimising growth performance in several shrimp species (D’Abramo & Conklin 1992). A comparison of the vitamin requirements of four shrimp species are given in Figure 2.

Minerals Minerals have many essential functions

in shrimp: they are components of the exoskeleton and other hard-soft tissues and act as activators in several enzymes

Figure 2: A comparison of the vitamin requirements for 4 shrimp species

32 | InternatIOnal AquAFeed | September-October 2011 September-October 2011 | InternatIOnal AquAFeed | 33

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IAF11.05.indd 33 02/09/2011 09:26

In particular, salmon is about to replace chicken on our plates.

Today, almost half of all seafood is issue of aquaculture. China is the world’s largest producer (at 33 million tonnes/year), while Europe produces 2.3 million tonnes year*.

To meet the demand whilst maintaining high quality, the aqua-culture sector has to face three challenges: increased volume (production has increased by 71 percent in the last 10 years and the trend continues), improving the sanitary conditions at the production site, and lessening the environmental impact (preserving the marine environment, reducing waste and respecting biodiver-sity).

A solution for the future of aquaculture

“Unlike other net materials such as nylon or coated nets, copper and its alloys are 100 percent recyclable without any loss of performance. Copper alloy nets perform well in difficult conditions and their lifespan is longer than other net materials,” explains Nigel Cotton, marketing manager at European Copper Institute.

In future, copper cages could allow the industry to exploit new areas of production in Europe, far from the coasts, since their resistance to sea currents and waves would enable off-shore breeding.

In Europe, the countries with

significant aquaculture activ-ities are Norway, Denmark, Faroe I s land , Spa in , UK, Por tugal , Ireland, Greece , Italy and Turkey, according t o U N FAO F i s h e r y Statistics 2009.

More inforMation:Irina DumitrescuCommunications ManagerEuropean Copper InstituteAvenue de Tervueren, 168 - box 10B-1150 BrusselsBelgiumTel: +32 2 7777070Fax: +32 2 7777079Email: eci@eurocopper.orgWebsite: www.eurocopper.org

6 | InternatIOnal AquAFeed | September-October 2011 September-October 2011 | InternatIOnal AquAFeed | 7

Aqua News

IAF11.05.indd 7 02/09/2011 09:20

use and increase the quality of the final product.

ReferencesFAO (2009). The state of world fisheries and aquaculture 2008. Rome, FAO Fisheries and Aquaculture Department, Rome. 176pp

D’Abramo LR (1998) Nutritional requirements of the freshwater Prawn Macrobrachium rosenbergii: Comparisons with species of penaied shrimp. Reviews in Fisheries Science 6: 153-163.

D’Abramo LR, Conklin DE (1992) New developments in the understanding of the nutrition of penaeid and caridean species of shrimp. In: Browdy CL, Hopkins SJ Eds, Swimming Through Troubled Water. Proceedings of the Special Session on Shrimp Farming, Aquaculture ’95, World Aquaculture Society, Baton Rouge, LA, USA, pp. 95–107.

Davis DA, Lawrence AL et al. (1993) Evaluation of the dietary zinc requirement of Penaeus vannamei and effects of phytic acid on zinc and phosphorous bioavailability. J of the World Aquaculture Society 24: 40-47.

Forster I, Dominy W et al. (2003). Rendered meat and bone meals as ingredients of diets for shrimp Litopenaeus vannamei (Boone, 1931). Aquaculture 219: 655–670.

Gillies JP, Faha PD (2003) Nutrigenomics: the Rubicon of molecular nutrition. J American Dietetic Association 103: s50–s55.

He H, Lawrence AL et al. (1992) Evaluation of dietary essentiality of fat soluble vitamins A, D, E and K for penaeid shrimp (Penaeus vannamei) Aquaculture 103: 177-185.

Kanazawa A, Teshima S, Sasaki M (1984) Requirements of the juvenile prawn for calcium, phosphorus, magnesium, potassium, copper, manganese, and iron. Mem Fac Fish Kagoshima Univ 33:63–71.

Match MD, Wahli W, Williamson G (2005) Nutrigenomics and nutrigenetics: the emerging faces of nutrition. The Federation of American Societies for Experimental Biology publishes The FASEB Journal 19: 1602–1614.

Muir JF, Roberts RJ (1982) Recent advances in aquaculture. London, Croom Helm.

Tan B, Mai K et al. (2005) Replacement of fish meal by meat and bone meal in practical diets for the white shrimp Litopenaeus vannamei (Boone). Aquac Res 36: 439–444.

Teshima S I (1997). Phospholipids and sterols. In D’Abramo LR, Conklin DE and Akiyama DM (Eds) Crustacean nutrition, advances in world aquaculture. World Aquaculture Society, pp 85-107.

shrimp biochemistry and physiology. The determination of mineral dietary require-ments is very difficult for aquatic animals because of their ability to absorb minerals directly from their environment.

Copper is important in the oxygen transfer agent in crustaceans, hemocyanin, and it is has been estimated that around 40 percent of the total Cu weight found in shrimps is contained within hemocyanin.

Copper is also required to achieve maximum growth and tissue mineralization, deficiency of Cu in P. vannamei has been characterized by poor growth and reduced concentrations of Cu in the carapace.

Excess Fe can produce toxic effects in shrimps, which can lead to decreasing growth in P. japonicas and zinc has been shown to have an important role in normal tissue mineralization in P. vannamei (Davis et al. 1993). A comparison of the macro and trace mineral requirements of 4 shrimp species is given in Figures 3 and 4.

ConclusionCurrent feeding methods are taking

advantage of shrimp omnivorous habits by incorporating plant-based ingredients in their diet.

Alternative sources of protein require supplementation of some essential amino acids, lipids and minerals in order to meet the nutritional requirements

of the shrimp species being cultured. By using the new research area of nutrig-enomics it is pos-sible to develop a more detailed u n d e r s t a n d i n g of how differ-ent components of the diet , e.g. cholesterol, can influence molec-ular mechanisms which in turn will help in under-standing their role in shrimp physiology and metabolism.

These future studies will enable strategies to be developed that will help us to better understand shrimp nutrition, optimise nutrient

pathways such as zinc activation of alkaline phosphatase.

Mineral supplementation is considered even more important for the freshwater prawns, like M. Rosenbergii since their environment contains less available minerals (Muir & Roberts 1982).

The macro minerals calcium (Ca), phos-phorous (P), sodium (Na) and potassium (K) have a special role to play in osmoregulation,

mineral and water equilibrium, and the maintenance of the acid-base balance. Davis et al. (1993) demonstrated that Ca and P are essential compo-

nents of hard tissues such as the exoskeleton of the shrimp and that calcium is necessary for impulse transmission, osmoregulation and muscle functions.

A dietary requirement for Na has not been demonstrated for marine shrimps, but in the case of pond grown shrimps, sup-plementation with salt (NaCl) has resulted in increased growth.

Both freshwater and seawater probably contain sufficient concentrations of Na and P to satisfy the requirements of shrimp, however Kanazawa et al. (1984) reported that diets with 0.9 percent of P improved growth in P. japonicus.

Trace minerals such as manganese (Mn), copper (Cu), iron (Fe), zinc (Zn) and sele-nium (Se) have important roles to play in

Figure 3: A comparison of the macro mineral requirements for four shrimp species

Figure 4: A comparison of the trace element requirements for four shrimp species

More inforMation:Mr Evert DrewesInternational business directorDishman NetherlandsEmail: Evert.Drewes@dishman-netherlands.com

34 | InternatIOnal AquAFeed | September-October 2011

F: Formulation

WHO CARES...…If profits in the aquaculture industry are as appetising as a seabass dinner?

As feed prices soar and formulation moves towards sustainability, aquaculture producers must maximise feed efficiency to stay on the menu.

In all phases of the fish’s life, proper nutrition will improve health. With decades of dedicated research, the “Alltech Aqua Advantage” programme can help improve growth and performance,

feed efficiency, flesh quality and immunity.

So, who cares about your customer’s profit? Remember

DOES!

Alltech European Bioscience Centre | SarneySummerhill Road | Dunboyne | Co. Meath | IrelandTel: +353 1 825 2244 | Fax: +353 1 825 2245 | www.alltech.com facebook.com/AlltechNaturally twitter.com/@Alltech

Silver Sponsor of

Visit our stand - No. 8-9

IAF11.05.indd 34 02/09/2011 09:26

34 | InternatIOnal AquAFeed | September-October 2011

WHO CARES...…If profits in the aquaculture industry are as appetising as a seabass dinner?

As feed prices soar and formulation moves towards sustainability, aquaculture producers must maximise feed efficiency to stay on the menu.

In all phases of the fish’s life, proper nutrition will improve health. With decades of dedicated research, the “Alltech Aqua Advantage” programme can help improve growth and performance,

feed efficiency, flesh quality and immunity.

So, who cares about your customer’s profit? Remember

DOES!

Alltech European Bioscience Centre | SarneySummerhill Road | Dunboyne | Co. Meath | IrelandTel: +353 1 825 2244 | Fax: +353 1 825 2245 | www.alltech.com facebook.com/AlltechNaturally twitter.com/@Alltech

Silver Sponsor of

Visit our stand - No. 8-9

IAF11.05.indd 35 02/09/2011 09:26

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Volume 14 I s sue 5 2 011

the international magazine for the aquaculture feed industry

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Energy efficiency improving and pellet uniformity control in the

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BIOMET Zn Aqua:A organic zinc source for aquaculture practices

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of essential amino acid requirements of fish

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