AQUAFEEDS AND FEEDING STRATEGIES IN SINGAPORE
Renee Chou

Marine Aquaculture Section, Department of Primary Production, 300 Nicholl Drive, Singapore 1749

CHOU, R. 1993. Aquafeeds and feeding strategies in Singapore, p. 354-364. In M.B. New, A.G.J. Tacon and I. Csavas (eds.) Farm-made aquafeeds. Proceedings of the FAO/AADCP Regional Expert Consultation on Farm-Made Aquafeeds, 14-18 December 1992, Bangkok, Thailand. FAO-RAPA/AADCP, Bangkok, Thailand, 434 p.

INTRODUCTION

Singapore has limited land and water resources. The contribution of agriculture (including fisheries and aquaculture) to GDP is less than 1%. Fish however, is an important source of protein for the population. The per capita fish consumption in 1991 was 40 kg. Of the 111,955 t of fish available in 1991,2% (2,000 t) with a farm-gate value of US$ 11.2 million was derived from aquaculture. This represents 17% of local fish supply. The rest is imported. About 98.6% of aquaculture production is from culture in the 79 coastal floating fish farms licensed in Singapore. Most of the cultured species are fed readily available and relatively cheap trash fish.

In 1991, about 100 million (valued at US$ 18.2 million) ornamental fish were produced by the 70 ornamental fish farms in Singapore. Singapore exports around 300 varieties and species to about 50 countries in the world. Most of the ornamental fish cultured are fed farm-made feeds or imported aquarium fish feeds, depending on the species. There is no commercial production of ornamental fish feeds in Singapore.

Commonly cultured finfish are the Asian seabass, (Lates calcarifer) groupers (Epinephelus tauvina, Plectropomus maculatus), snapper (Lutjanus argentimaculatus, L. johni). The banana shrimp (Penaeus merguiensis) is the only cultured shrimp species in Singapore. Ornamental fish cultured are the guppy (Poecilia reticulata), and other poecilid species like the mollies (P. sphenops, P. latipinna), swordtail (Xiphophorus helleri) and platys (X. maculatus, X. variatus), corydoras (e.g. Corydoras aeneus), goldfish (Carassius auratus), tetra (e.g. Paracheirodon innesi) and discus (e.g. Symphynodon aequisasciatda).

AVAILABILITY OF FEED INGREDIENTS

Trash fish (US$ 270-300/t) is presently the most popular feed being used in marine food fish culture. Other feed ingredients available in Singapore that are suitable for aquafeed preparation have historically been those imported for the pig and poultry industries. These are generally not of the specifications orquality required for aquaculture, especially in meeting the nutritional requirements of the carnivorous species cultured here. Thus feedstuffs specifically for aquafeed manufacture have to be imported, e.g. shrimp meal, squid meal, and high protein fish meal.

Tables 1 and 2 show lists of aquaculture feed ingredients that are imported by local feedmills for shrimp feed production. The same are used for fish feed production, which is still in its infant stage. These ingredients are generally of higher protein and quality than for terrestrial animal feeds and, of course, more expensive. Wheat bran, oat meal, wheat flour and the milk-based products are used in farm-made feeds for ornamental fish.

* S$ 1.65 = US$ 1.00 (December 1992); original ingredient source may be different fromcountry of import

Carbohydrate (%):

** = 93.7,
*** = 83.6,
**** = 66.0,
^***** = 66.6

* original ingredient source may be different from country of import

AQUAFEED MANUFACTURING INDUSTRY

Complete statistics on imported aquafeeds are unavailable. However, in 1992, about US$ 66 million of animal feeds and feedstuffs were imported, of which US$ 56 million worth was re-exported. Local exports were estimated to be worth US$ 26 million. Of this, about 15% were aquafeeds, mainly for shrimp, worth US$ 3.9 million.

Marine foodfish and shrimp

The 3,500 t of dry pelleted complete feeds (hatchery and postlarval, starter, grower, and finisher feeds) for penaeid shrimp, valued at US$ 3.8 million, manufactured by the four local feedmill companies in Singapore in 1992, was about 50% of the 1991 production level. Nearly all was formulated for tiger shrimp (Penaeus monodon), but used to culture banana shrimp in Singapore. A list of feed mills is given in Annex 1, while the cost of their feeds is given in Table 3. Table 4 presents the proximate analyses stated by the manufacturers of these feeds. Most of these feeds are exported to other ASEAN countries.

Shrimp feeds are also imported (statistics not available) from the region for local use. Their composition and price are competitive with locally produced feeds, since no import tax is levied.

* Zoeal Feed : < 30 μm
Mysis Feed : 30-90 μm
Early PL Feed : 150-250 μm
Late PL Feed : 250-400 μm

Ornamental fish (mainly freshwater species)

As stated earlier, most ornamental fish are fed farm-made feeds. No commercial feeds are produced locally. About 7 t is imported from the region, with an estimated value of US$ 182,000.

ON-FARM FEED FORMULATION AND MANUFACTURING

Marine foodfish

On-farm feeds are prepared by a few farmers for marine finfish such as seabass, snappers and groupers during the monsoon months, when trash fish supplies are limited by the inability of local trawlers to set sail during rough weather. Formulation is simple, comprising fish meal (30%), commercially available vitamin and mineral premixes (0.5%) and corn gluten binder (69.5%). The resultant formulation has a crude protein level of about 57%, and is used without ground trash fish.

Alternatively a formulation including ground trash fish (30-50%), a binder meal comprising fish meal (30-50%), plant ingredients such as soybean and rice bran (30%), corn gluten or wheat flour (20-30%), and vitamin and mineral supplements (1-2%) is used. No special equipment is needed (only ordinary meat grinders). The mixture is hand-mixed with ambient or hot water to gelatinize the starch, formed into dough balls and fed by hand to the fish. One farm feeds a crude formulation of fish meal, plant material (soybean meal, bran) and starch binder without the trash fish and has reported that the feed is well accepted and beneficial to fish like seabass.

Commercial preparations of complete seabass nursery mash and seabass nursery and grow-out dry pelleted feeds are also available from feedmills in Singapore. One hatchery operator produces nursery stage seabass (1.3 cm total length, 0.5g) on a commercial (imported) dry mash which he combines with water and feeds (by hand) as wet pellets, in place of ground trash fish and live food. He reports that this saves on labour and promotes more uniform growth. The amount imported is still negligible. Fish growth and performance are not compromised. Dry pelleted seabass feed manufactured by one Singapore feedmiller is being tested in collaboration with the Primary Production Department (PPD).

Shrimp are fed dry, commercially available pelleted feeds in Singapore; no farm-made feeds are in use.

Ornamental fish

Ornamental fish like the guppy, platy, swordtail and molly are fed by hand on farm-made feeds. Farm-made diets for the guppy (adults and fry) consists of about 70-80% ground wheat bran or oats, 10-15% of either fish meal, poultry starter crumbles, eel mash or ground dried shrimp, and 5-20% skimmed milk or buttermilk powder and soybean meal. The dry composition of such diets is usually 15-34% crude protein, 48-77% nitrogen-free extract and 3-7% ether extractable fat. The diets are supplemented with tubifex (Tubifex spp.) worms (for adult guppy) and the cladoceran, Moina spp. (for fry).

Farm-made diets for the platy and swordtail are similar, consisting of a mixture of fish meal and wheat bran/flour at 60-80% and 20-40% respectively. The dry composition of these diets is 18-21% protein, 61-63% nitrogen-free extract and crude fat around 5%.

In contrast, the molly, which is essentially herbivorous, is fed bread crusts (about 12% crude protein) to supplement the zooplankton, phytoplankton and algae in the ponds. About 90% of the farmers practise this, as such feeds are cheaper than imported commercial feeds.

No special equipment is needed for preparing aquarium fish feeds on the farm, as the feeds are mixed by hand.

ON-FARM FEEDING STRATEGIES

Marine foodfish

Trash fish is fed twice daily, usually in the morning and towards evening, and at slack tide to minimize loss. The fish are fed small quantities at a time to prevent wastage. Fingerlings are fed up to 10% of their weight at first, 8% in early grow-out, and 5-3% in late grow out, until they attain the marketable weight of 500-700g. Broodstock (>3kg) are fed at 3%.

Fish are fed farm-made feeds at 5-3% of the fish body weight since they contain less moisture than trash fish. Farm-made broodstock feeds have an advantage in that the dough mix can be supplemented with fish oils known to enhance egg quality. Grow-out stocking rates are 4-5 kg/m³, while broodstock are stocked at 13 kg/m³.

Ornamental fish

Ornamental fish, reared in ponds, fixed netcages in ponds and tanks stocked at 2,000-4,000/m³, are fed farm-made feeds, broadcast by hand as a wet mash. Farm-made feeds are given 2-3 times per day (morning, at noon and in the evening), and live food supplement once a day (mornings).

MAJOR INSTITUTIONS INVOLVED IN AQUAFEED RESEARCH AND DEVELOPMENT

The Primary Production Department (PPD) is involved mainly in marine foodfish (seabass and banana shrimp) feed development. The Department's Marine Aquaculture Section (MAS) represents Singapore in the 5-year ASEAN-EEC Aquaculture Development and Coordination Programme (AADCP), which began in 1990. Component 4 of the AADCP involves the PPD (ASEAN institute) and its twinned European institute, the Institut Francais de Recherche pour l'Exploitation de la Mer (IFREMER), with inputs from the Institut National de la Recherche Agronomique (INRA). Component 4's objective is to develop adequate marine aquafeeds, specifically for seabass and banana shrimp.

The Zoology Department of the National University of Singapore has worked on microencapsulated feeds for larval seabass, and on the nutritional requirements of some aquarium fish species e.g. guppy.

A commercial feedmill is also engaged in aquafeed research and development, particularly on value-added microfeeds and enhancer diets for penaeid shrimp and seabass feed.

CURRENT NATIONAL REGULATIONS

According to the Feeding Stuffs Act (1985), the Director of Primary Production is responsible for giving licences to manufacture, prepare, market and import animal feeds in Singapore. This includes the inspection of feedmills and of the quality of the feeds produced. Purchasers of animal feed can (upon payment of the appropriate fee) have samples taken by PPD and analysed, and receive a certificate of the results.

CURRENT PROBLEMS AND CONSTRAINTS

Even though Singapore does not have indigenous raw materials for feed manufacture, its excellent central location and good communication and transport infrastructure allows feedmillers and agents to select and import feedstuffs and feeds of good quality from most parts of the world. Aquafeed manufacturers are challenged by the highly competitive climate in the region (directed mostly at tiger shrimp feed production) although labour costs can be relatively high and there is lack of open information on the nutritional requirements of fish and shrimp species grown in the region. The latter is common to the region and limits optimisation of feed formulations (hence their performance).

TRENDS IN AQUAFEED MANUFACTURING AND USE

Some feed companies in Singapore are expanding their operations into the region, setting up production facilities overseas, while retaining their local feedmills and offices as technical resource centres. This is to take advantage of Singapore's good communication, banking and industrial services infrastructure. In Singapore, these companies are venturing into seabass feed development, the production of shrimp hatchery feeds and the development of valueadded feeds.

In 1991, 6,520 t of aquafeeds (mainly shrimp nursery and grow-out feeds, valued at US$ 7.4 million), were manufactured in Singapore. In 1992, production was about half this level. One feedmill is now producing value-added hatchery shrimp feeds (viz for shrimp zoeal, mysis, early postlarval and late postlarval stages), and has transferred its nursery and grow-out feed production abroad where it has a feedmill within the proximity of major users. This ensures product freshness and saves on labour and transport.

Prospects and plans for changes in aquafeed manufacture for the future are therefore dependent on prevailing conditions in the region.

In the case of farm-made feeds, they will probably continue to be secondary to trash fish, unless the availability and/or price of the latter becomes prohibitive or until nutritionally adequate and tested commercial feeds become available or more economical to use.

AQUAFEEDS AND FEEDING STRATEGIES IN THAILAND
Pisamai Somsueb

National Inland Fisheries Institute Kasetsart University Campus, Bangkok 10900, Thailand

SOMSUEB, P. 1993. Aquafeeds and feeding strategies in Thailand, p. 365-385. In M.B. New, A.G.J. Tacon and I. Csavas (eds.) Farm-made aquafeeds. Proceedings of the FAO/ AADCP Regional Expert Consultation on Farm-Made Aquafeeds, 14-18 December 1992, Bangkok, Thailand. FAO-RAPA/AADCP, Bangkok, Thailand, 434 p.

INTRODUCTION

In the past, fish production in Thailand depended on natural resources but a national reservoir construction programme, aimed at the development of agriculture, irrigation and industry, led to a decline in natural fish stocks. The reservoirs are serving agricultural production and prevent flooding but have an adverse effect on fisheries by reducing spawning and larval rearing grounds. Moreover, industrial development and the expansion of agriculture has resulted in increased water pollution. All these factors have directly and indirectly reduced capture fisheries production. The Department of Fisheries is attempting to increase fish production by promoting aquaculture. Today, aquaculture production seems to surpass the natural catch.

* estimate

Figure 1. Captured and cultured freshwater fish production in Thailand

Between 1978 and 1990, freshwater fish production from aquaculture increased significantly and is estimated to have done so again in 1991 and 1992. In 1978 the production of freshwater capture fisheries was about 102,000 t, but was reduced to less than 82,000 t by 1988. However, there has been an increase since then. Production from inland aquaculture had increased from 39,000 t in 1978 to nearly 104,000 t by 1990 (Table 1 and Figure 1).

As shown in Table 2, between 1978 and 1990 the number of freshwater fish farms increased from 24,000 to nearly 62,000 while their total area grew from 24,000 ha to nearly 46,000 ha in 1988 but has decreased since then. The main area for freshwater fish culture is the central part of Thailand. Here the number of farms is only 25% of the total, with an average area of 2.0 ha/farm, but the volume of fish produced in this area is nearly 70% of national production (Table 3). The Northeast is the second most important area, which has the highest number of farms (45%) with an average culture area of 0.26 ha/farm. In the North there are about 15,600 farm units (25%) with an average area of 0.29 ha/farm. The least important area is the South, where the number of farms is only about 3,000 (5% of the total) with an average area of 0.05 ha/farm. Production of freshwater fish in the northern and southern parts of the country is generally low, compared with the central region, as shown in Figure 2.

Figure 2. Freshwater fish farms and their production in different parts of Thailand in 1990

There are many economically important cultured aquatic species in Thailand, such as Tilapia sp., Puntius gonionotus, Pangasius sutchi, Trichogaster pectoralis, Clarias sp., Channa striatus, Macrobrachium rosenbergii, etc. Some marine species are also important for aquaculture, providing export commodities and high income. Farmers prefer to culture seabass (Lates calcarifer) and shrimp (Penaeus monodon) because of their high farm-gate value. The area under shrimp culture had reached nearly 76,000 ha by 1989 but had declined to 65,000 ha by 1990 (Figure 3). The national production was nearly 108,000 t in 1990 (Table 4).

Most of the seabass is cultured in cages and is limited to certain locations. About 68% of seabass farms are in five southern provinces. Shrimp farms produce the highest value among coastal farms. Because of the high farm-gate value of marine shrimp, many farmers shifted to growing shrimp. This caused environmental problems because shrimp farms invaded the coastal mangroves. The rapid growth of shrimp farms without proper regulations and control resulted in water pollution and serious disease outbreaks. The Department of Fisheries has realized the problem and is educating shrimp farmers in order to introduce proper farm management techniques. Today, many shrimp farms in the eastern and southern part of Thailand still have high production.

Figure 3. Number, area and production of shrimp farms in Thailand

AVAILABILITY OF FEED INGREDIENTS

Most of the raw materials used in aquafeeds can be produced in the country but domestic production of some important ingredients, such as soybean, fish meal and sesame meal, is insufficient because they are also used for manufacturing poultry feed. Table 5 shows domestic production and imports of feed ingredients.

The most important growing areas for oil crops (soybean, peanut and sesame) are the north and the northeast. Oil palm production is concentrated in the south. Although domestic production of soybean in 1990 was 190,000t, the demand for it is even higher, therefore significant amounts have to be imported (340,000 t in 1990). Domestic food crop production almost satisfies the demand. The most important growing areas are in the central, northern and northeastern part of the country. Only maize is imported at about 723,000t/yr.

Problems in producing feed ingredients may arise as the area under culture is not expanding while the demand increases every year. The average yield in the planted area was low because of the low quality of the seed; this results in low quality and quantity of production. The government tries to solve this problem by coordinating with the private sector in improving seed quality, maintaining cash flow and assisting farmers to complete their crop cycle. Availability of feed ingredients of good quality and in high quantity is expected in the next few years.

Another important feed ingredient, fish meal, is used in high amounts in animal feeds, so the demand is high. Fish meal, especially with a protein content over 60%, has to be imported. Low domestic fish meal production is the result of many factors, such as decreases in the fishing area and the catch.

The price and composition of the major feed ingredients available in Thailand is presented in Table 6, while compositional data for some traditional ingredients is given in Table 7.

AQUAFEED MANUFACTURING INDUSTRY

There are 13 feed mills producing aquafeeds in Thailand. Most of these originally produced livestock and poultry feeds. Nine of the mills only produce shrimp feeds; the others manufacture both shrimp and fish feeds (Annex 1).

About 88% of the 382,000 t of aquafeeds produced in the country in 1990 were shrimp feed; 11% were for carnivorous fish species and only 1% for herbivorous fish. Feed exports are only 3% of the total. Most of the feed factories produce shrimp feeds because the demand is high. Because of the high farm-gate value of shrimp, farmers have the capability to buy factory-made feeds. Although carnivorous fish (e.g.catfish) are popular farmed fish, their farm-gate value is low compared to shrimp. The price of catfish is only one-third to two-thirds of the price of shrimp. Low fish prices have forced farmers to use traditional, farm-made moist feeds. Since the farm-gate value of herbivorous fish is even lower (US$ 0.4-0.8/kg), farmers try to decrease production costs by using household byproducts and plants instead of dry feeds. However, if herbivorous fish culture is promoted to a commercial scale and produces good quality fish, farm-gate value could increase, rendering the use of commercial feeds more feasible.

Aquafeed produced in the country is available for five different aquatic species groups. These are marine shrimp, freshwater prawns, catfish and tilapia, for which complete diets are manufactured, and herbivorous fish, for which supplementary feed is available. Nutritional values and prices of these commercial feeds are presented in Table 8.

ON- FARM FEED FORMULATION AND MANUFACTURING

More than 50% of cultured freshwater fish is used for household consumption. Most species are of low farm-gate value, therefore simple types of feeds are used. Only a few fish farms have their own equipment to produce farm-made feeds. Farmers are trained in feed formulation and preparation by government or private agencies. Information on fish nutrition is generated mainly by government institutions, primarily by the Feed Quality Control and Development Division (FQCD) and the National Institute of Coastal Aquaculture (NICA) of the Department of Fisheries which are the core institutions for basic and applied research (Figure1).

Typical feed formulae which have been extended to farmers by FQCD are shown in Tables 9-14. Some traditional feeds used by the farmers are shown in Tables 15 and 16; these consist of two or more ingredients mixed together. Premixes are sometimes used. Ingredients are roughly mixed and ground in a meat mincer to form a slurry or a paste. Minced feeds are distributed to the ponds by hand, shovels or buckets for most of the species. For some species (like snakehead) the moist feed has to be placed on wooden platforms in order to ensure proper feeding.

ON-FARM FEEDING STRATEGIES

When culturing carnivorous species in running water systems, stocking rates are about three times higher than in herbivorous fish culture. The stocking densities of clarias catfish in ponds are extremely high, varying from 75 to 400/m², representing the highest stocking densities in fish culture. The stocking density of shrimp is currently only 20-40/m². Farmers pay attention and take much care in rearing shrimp because they are sensitive to environmental changes and the investment in shrimp culture is high.

Farmers can make more profit by practising integrated farming or polyculture where few feed inputs are required and the natural productivity can be maximized. Integrated farming means culturing fish in ponds under chicken, duck or pig houses. Suitable fish species for integrated farming are Tilapia sp., Pangasius sp. and Puntius sp. The proper stocking ratios of the animals in integrated farming are 1,250 chicken or ducks or 30-60 pigs together with 12,500 fish/ha. Polyculture is most successful when fish species with different feeding behaviour are selected, such as tilapia, silver carp, striped catfish and bighead carp. The stocking rate for these four species in polyculture could be 3:3:3:1 respectively at a stocking rate of about 10/m².

Normally the daily feeding rate of fish is about 10% of body weight from fry to fingerling stages; it is then decreased to 5% of body weight in the juvenile and adult phases. Some shrimp farmers re-calculate feed requirement every two weeks in order to minimize feed loss and to decrease feeding costs.

The feeding frequency of fish is usually 3-4 times a day in the larval/ fingerling stage and twice a day from the fingerling stage to marketable size (Table 17). In the case of marine shrimp feeding frequency is much higher, because they eat gradually. Farmers feed shrimp with commercial sinking pellets but, in the final month before harvesting, trash fish or mussels are used once a day in the evening to induce maturation.

Extensive fish culture normally utilizes fertilizers in the nursery ponds. Herbivorous fish culture relies on natural food in the pond promoted by the addition of organic and inorganic fertilizers. Farmers prefer to apply chicken manure at a rate of 900-1,500 kg/ha/week. If cattle manure is used, relatively less is applied.

Water exchange usually starts in the grow-out phase or when the water quality deteriorates. In shrimp ponds during the first month of culture no water exchange is needed; later about 15-30% of pond volume is exchanged and paddle wheels or air jet aerators are employed to increase dissolved oxygen. About 4 air jet aerators are required for a pond with an area of 0.6 to 1.0 ha.

MAJOR INSTITUTIONS INVOLVED IN AQUAFEED RESEARCH AND DEVELOPMENT

In Thailand, fish nutrition research is undertaken primarily by two institutions (Figure 4) under the control of Department of Fisheries, namely the Feed Quality Control and Development Division (FQCD) and the National Institute for Coastal Aquaculture (NICA). These two institutions coordinate their work with various fishery stations located throughout the country. FQCD is the centre for feed quality control and implements intensive research work on the nutrient requirements of freshwater fish. Its work includes the development of cost-effective feed formulae, using locally available feed ingredients. The nutritional research of NICA concentrates on marine fish species. NICA coordinates with those fishery stations which are involved in coastal aquaculture. NICA's experimental work focuses on determining the nutrient requirements of marine fish and shrimp and on feed development for them. At universities, research work is mainly carried out by students under the supervision of faculty staff. Every summer, students from many universities come to local fishery stations and institutes involved in fish nutrition research to broaden their experience and to use the facilities.

Figure 4. Organization of aquafeed research and development in Thailand

The facilities for feed and feed ingredient analysis at FQCD and NICA include equipment for proximate analysis, gas chromatography (GC) for fatty acid analysis, and high performance liquid chromatography (HPLC) for amino acid and vitamin analyses.

CURRENT NATIONAL REGULATIONS

Regulations controlling aquafeed manufacturing, marketing and feed quality in Thailand were issued by the Ministry of Agriculture and Cooperatives in 1992. These are similar to the regulations controlling poultry feed manufacturing, marketing and quality. The responsible unit in the Ministry is the Department of Fisheries (DOF) which, in turn, has assigned the Feed Quality Control and Development Division (FQCD) to implement control. The regulationsareshown in Annex 2.

CURRENT PROBLEMS AND CONSTRAINTS

Total production of cultured freshwater fish in 1992 was about 114,000 t (Table 1). Assuming that this resulted from feeding dry commercial feeds with an average AFCR of 1.5:1, approximately 171,000 t of feed would have been required. However, only 46,000 t of freshwater fish feed are produced annually. The difference indicates that not all fish farmers depend on commercial feeds. The main constraint faced by farmers in the use of dry formulated feeds is that the cost may exceed the market value of some freshwater species. For instance, the market value of striped catfish, tilapia and tawes averages US$ 0.36/kg, US$ 0.44/kg and US$ 0.64/kg respectively, while the cost of feeding (assuming AFCR is 1.5:1) is US$ 0.57/kg of fish produced. This constraint leads to little or no use of formulated feeds and to the use of more fertilizers or traditional feed resources to reduce production costs. Therefore, the use of formulated feeds is limited to species with high market value.

Some farmers refuse to use dry commercial feeds as they do not believe that dry feeds could satisfy the needs of fish. The traditional feeds are moist feeds, such as trash fish mixed with rice bran. Regardless of nutritional value, farmers believe that wet feeds would satiate fish better than dry feeds.

Fattiness in the flesh of some species, such as striped and walking catfish, is favoured by fish consumers. Therefore, high energy feed sources are required rather than dry feeds. Poultry viscera, broken rice and kitchen wastes are still the feeds of choice for several farmers raising catfish.

TRENDS IN AQUAFEED MANUFACTURING AND USE

Aquafeed manufacturing and use is expected to increase in the next few years because the use of traditional or farm-made feeds is highly site- and timespecific. Although preparing farm-made feeds is practical and cost effective for certain farmers, it may not be so for others, due to the unavailability of unconventional raw materials. The quality and quantity of farm-made feeds cannot be controlled properly, resulting in unpredictable fish production. Furthermore, the ingredients traditionally used for farm-made feeds are becoming less and less available. Farm-made feeds also disintegrate rapidly in water causing problems to the aquatic environment. For these reasons, aquaculture cannot expand rapidly unless more conventional types of feeds are used.

Shrimp feed manufacturing is steadily increasing every year. There are also many other economically important aquatic species which are interesting to farmers, such as seabass, groupers and frogs. Although the nutritional requirements of these species are not totally known, many feed manufacturers have already produced and marketed feeds for them.

The number of feed mills in Thailand is not expected to increase, however, because new ones may not be able to compete with the existing large mills. Feed production is expected to increase through the expansion of existing feed mills.

Annex 2. Thai aquafeed regulations (1992)

The Minister shall have power to publish notification in the government gazette prescribing:

1. the name, category, type and/or description of the animal feed;

2. the quality standard of the animal feed according to the species, genus, family or age of the animal as well as rules and procedures of production or exposition of such animal feed for sale;

3. the name, category, type and/or description of the animal feed to be permitted or prohibited to import for sale;

4. the name, category, type and/or description of the feed additive allowed to be mixed in the production of an animal feed for sale as well as the minimum and maximum ratio or quantity of such additive in the mixture;

5. the production procedure, equipment or facilities used in the production and storage of animal feed produced or exposed for sale from deterioration;

6. the quality or standards and use thereof, as well as materials which are prohibited to be used, of containers for animal feed for sale.

FQCD shall appoint a committee in order to give advice or opinions (on the description of aquafeeds, consideration of appeals, suspension of licenses, etc) to the Director-General and has the power to issue written orders requiring any person to give a statement or submit any relevant document or evidence to supplement its consideration.

No-one may produce or import for sale any aquafeed, unless a license has been granted for production or import. Any licenses to produce or import for sale of a particular type of animal feed must first be registered with the competent office and receive a certificate of registration from the Director-General of the Department of Fisheries.

AQUAFEEDS AND FEEDING STRATEGIES IN VIETNAM
Le Thanh Luu

Research Institute for Aquaculture No.1 Dinh Bang, Tien Son, Ha Bac, Vietnam

LUU,L.T. 1993. Aquafeeds and feeding strategies in Vietnam, p.386-396. In M.B. New, A.G.J. Tacon and I. Csavas (eds.) Farm-made aquafeeds. Proceedings of the FAO/AADCP Regional Expert Consultation on Farm-Made Aquafeeds, 14-18 December 1992, Bangkok, Thailand. FAO-RAPA/AADCP, Bangkok, Thailand,434 p.

INTRODUCTION

Aquaculture in Vietnam plays an important role in meeting the protein needs of the people. In 1991, the production of aquaculture (300,000 t) significantly increased (Table 1 and Figure1) due to the application of the semiintensive approach; this resulted in considerable enhancement of pond productivity (Table 2). Table 1 also shows that aquaculture dominates the production of freshwater fish and prawns, constituting 81% in 1990 and 91% in 1991. Freshwater fish production comprised 35-45% Chinese carps, 25-30% Indian major carps, 20-30% indigenous species (e.g. clariad and pangasid catfishes, mud carp, snakehead, etc.), 1-2% tilapia and 12-13% prawns.

* 1992 data are planned

Figure 1.Growth of fish production in Vietnam

Unfortunately, there are no statistical data on the contribution of aquafeeds to aquaculture production. Aquaculture in Vietnam is still based on the traditional polyculture approach within which the application of semi-intensive systems with some supplementary feeding began quite recently.

AVAILABILITY OF FEED INGREDIENTS

Like many tropical countries, Vietnam has an abundance of feed ingredients for animals and fish. In the list of feed ingredients available in Vietnam there are more than 50 entries of which nine are considered major raw materials. The data given in Table 3 indicate significant production of rice, other cereals, tubers and other feed ingredients. These crops, e.g. maize, soybean, cassava, sweet potato, etc. are harvested in different seasons depending on the geographical location of each region.The cost of these products is lowest in the harvesting period and increases afterwards. After harvest the price of cereals often increases by 10-15%. The approximate cost of major animal feed ingredients is given in Table 4. However, prices may be 10-20% less if the products are purchased locally and in large amounts.

Fish meal is considered the main animal protein resource. However, domestic production of fish meal is limited (it was 8,500 t in 1992) due to the high cost of raw materials and transport. About 80-85% of the fish meal is produced in the south and only 15-20% in the north of the country.

Only a few feed ingredients (such as vitamins A, B, C, D and lysine) are imported; they are used to produce premixes. The amount of imported vitamins of all kinds is estimated be about 0.1-0.15 t/yr, while the amount of imported lysine ranges from 3.0 to 3.5 t/yr.

AQUAFEED MANUFACTURING INDUSTRY

Unfortunately, industrial-scale manufacturing of aquafeeds in Vietnam is limited, although there are many medium-sized factories producing animal feed. In the north of Vietnam during the past two decades 20 feed mills were constructed with an installed capacity totalling 94,000t. In the south the number of feed mills is 10, with a total installed capacity of 83,200t per year. The actual production of all these feed mills reached 22,600 t, which is about 13% of the installed capacity (Annex 1). As much as 65% of the produced animal feeds are used for chicken, 30% for pig raising and the rest for dairy cows. None of these factories has produced aquafeeds.

In the fisheries sector 14 local feed mills with an installed capacity of about 2,300t/yr have been constructed to produce feeds primarily to meet the demand, which is still low, from shrimp culture (Annex 2). At present these plants are producing only about 800 t/yr. These feeds are used by farmers in pelleted form as supplementary feeds.

Averages of the most important biochemical parameters of feed samples collected from various factories and shops are shown in Table 5. Experiments with locally produced grow-out feeds in Penaeus monodon ponds have shown that yields up to 0.5-2.0 t/ha/crop may be achieved with fairly high food conversion rates (3.0-4.0:1).

ON FARM-FEED FORMULATION AND MANUFACTURING

In Vietnam there are few laboratories involved in research on fish and shrimp nutrition. Research projects are scattered and very limited due to shortage of funds, without which nothing can be done. The experimental feeds formulated by the Research Institute for Aquaculture No.2 have rather high protein content and cost about US$ 780-960/t. Meanwhile, a group of scientists from the Research Institute for Aquaculture No. 1, using a simple computer programme “FORM”, have formulated various types of feeds for carp broodstock, for rohu and mrigal, for Penaeus monodon, P . merguiensis and Macrobrachium rosenbergii. Some of these formulae are given in Tables 6-8.

On their own farms farmers are using raw materials or home-made feeds to feed shrimp, carbs and cage cultured fish. In the north, farmers use soybean milk, and cooked chicken and pig feeds to feed larvae during the rearing period. Grass carp in cages are fed cassava, cassava leaf or sweet potatoes. Raw trash fish and krill, as well as small, soft-shelled molluscs are used for feeding shrimp and crabs in ponds. In the south farmers also use trash fish for feeding cultured Pangasius and other fish species cultured in cages and Penaeus monodon in ponds. Some farmers have been encouraged to use commercial feeds for shrimp in their grow-out ponds and have achieved success. However, farmers still prefer to use their farm-made feeds as they seem to be cheaper than commercial feeds.

For preparing farm-made feeds farmers are using very simple grinders and pelleting machines. In rural areas, where there is no electric energy supply, farmers have to use generators to operate their machinery. The operational scheme of farm-made aquafeed processing in Vietnam is as follows: ingredients are sun-dried, ground, stored separately, mixed and then pelleted (Figure 2).

Figure 2. Large mincer for producing aquafeeds in Vietnam

ON-FARM FEEDING STRATEGIES

As commercial feeds are only used by a few farmers, official guidelines or instructions on feeding rates have not been issued for any of the cultured species. However, from our experiments, a daily rate of 5-7% of body weight for shrimp has been recommended for ponds in warm weather and 3-5% in cold weather. Shrimp are fed twice per day; 20% of the daily ration is fed in the morning and 80% in the evening.

Farmers tend to feed their cages or ponds according to the availability of feeds. They also learn through experience to reduce or to increase the feeding rate by checking the food remaining in feeding trays.

MAJOR INSTITUTES INVOLVED IN AQUAFEED RESEARCH AND DEVELOPMENT

The three institutions in Vietnam involved in aquafeed research and development are the following:

• Research Institute for Aquaculture No 1, (Vien Nghien Cuu Nuoi Trong Thuy San 1) Ministry of Fisheries, Dinh Bang, Tien Son, Ha Bac (Telephone 271368);

• Research Institute for Aquaculture No 2, (Vien Nghien Cuu Nuoi Trong Thuy San 2) Ministry of Fisheries, 117 Nguyen Dinh Chieu, Ho Chi Minh City (Telephone 299592); and

• Research Center, State Committee for Science and Technology (Trung Tam Nghien Cuu Thuc Nghien), 1 Mac Dinh Chi, Ho Chi Minh City.

CURRENT NATIONAL REGULATIONS

No regulations, technical recommendations or instructions concerning different aspects of aquafeed manufacturing or use have been issued in Vietnam so far.

CURRENT PROBLEMS AND CONSTRAINTS

As was pointed out above, commercial aquafeeds are not yet widely used in Vietnam. The reasons are many, which include:

-   the price of aquafeeds is very high (Table 9), requiring rather high inputs from the farmers practicing aquaculture, while the price of their products in domestic markets seems to be rather low (Table 10);

• government support is not yet strong. As a result research and development funds are very limited;

• there is a lack of economic data on the benefits of feed utilization, therefore no specific guidance has been given to the farmers.

TRENDS IN AQUAFEED MANUFACTURING AND USE

Shrimp and crab culture, as well as fish culture in cages, commenced only a few years ago. No doubt recent Government policy, which allows farmers to have control over water areas for aquaculture with low taxation rates, will encourage them to apply semi-intensive methods. Up to two years ago only cooperatives were allowed to use water for aquaculture. The annual demand for aquafeeds will certainly increase. According to our estimate, aquafeed demand will double every year and by the end of the century the area used for semi-intensive aquaculture systems will reach about 50-55% of the total area under fish and shrimp culture. Cage culture of carp as well as suitable marine fish species (e.g. seabass and groupers) will develop on a larger scale.

LIST OF REFERENCES

Anon. 1992. Statistical Data of Vietnam Agriculture, Forestry and Fishery (1976-1991): the Pivotal areas of Commodity Production. Statistical Publishing House, Hanoi. 349 p.

Ministry of Fisheries. 1992a. p. 21. In Annual Report for 1991. Hanoi, Vietnam.

Ministry of Fisheries. 1992b. National fisheries policies and investment priorities during the period 1991-2000. Paper presented at the ICD Workshop: Fishery Industry Development, May, 1992.

* according to name of location

Source: Department of Science and Technology, Ministry of Agriculture

* according to name of location

Source: Department of Science and Technology, Ministry of Fisheries