PART III COUNTRY REPORTS (Cont.)

COUNTRY PAPER
(Philippines)

FEEDS AND FEEDSTUFFS FOR AQUACULTURE USE IN THE PHILIPPINES

by

Sofia S. Basa¹

1. INTRODUCTION

Like land animals, fish in order to grow and reproduce need complete food nutrients in their diet. Since the modern trend now in aquaculture is towards intensive farming, the use of formulated diets, supplementary or complete diets that are economical and viable is being resorted to. Feed is one of the major production inputs in the intensive production of Penaeus monodon.

1.1 Importance of feeds to aquaculture

Feeds constitute about 70–80 percent of the total production cost for prawn farming. Using supplement feed, one can double the stocking density and also can harvest marketable size one month earlier than without supplementary feeding. More cropping per year can be realized.

In the Philippines, the traditional practise is fertilizing the fishponds to culture the natural food organisms before stocking the fish. This requires thorough preparation but most often the natural food is not enough to support the needs of the fish being cultured until they reach marketable size, hence the need for supplemental feed.

2. FEED INGREDIENTS AVAILABLE IN THE COUNTRY

2.1 Feedstuffs for aquaculture use

Because some fishes respond positively to artificial diets, different conventional and non-conventional feedstuffs such as fish meal, soybean meal, copra meal, ipil-ipil leaf meal, ricebran, sorghum, meat and bone meal, hydrolyzed feather meal, algal meal, cottonseed meal and composted water hyacinth (Cruz and Laudencia; 1987; Santiago, et.al., 1982; Natividad, 1980) can be used in aquaculture.

However, each feedstuff in any diet formulation should be present for a specific reason, i.e., it is a good energy source, it is rich in a limiting amino acid, etc. In addition, each feedstuff in a particular diet formulation should be the least costly ingredient available for its particular function in the diet. This leads to another assumption in feed formulation, that is, any nutrient in a particular feedstuff such as amino acid is just as valuable as the same nutrient in any other feedstuff. This allows feed formulators to interchange one feedstuff with another as cost and fluctuation of availability.

2.1.1 Legumes

“Ipil-ipil” leaf meal prepared from Leucaena leaves is one of the promising sources of plant protein for compounded prawn feeds. In the Philippines, 1 kg of shrimp head meal or fish meal cost more than two or four times, respectively that of dry Leucaena foliage (Pascual and Tabbu, 1980). Leucaena leucocephala called “ipil-ipil” in the Philippines is being propagated for fuel. This fast growing plant offers probably the widest assortment of uses of all tropical legumes.

Pascual (1983) recommended the use of Leucaena leaves at a level of 10 percent of the dry weight as an alternative protein source in formulated feed for P. monodon. Soaking the leaves in freshwater for 24 hours is efficient in extracting toxic amino acid mimosine.

¹ Supervising Aquatic Resources Development Specialist, Department of Agriculture, Bureau of Fisheries and Aquatic Resources, 860 Arcadia Bldg., Quezon Avenue, Quezon City, Metro Manila, Philippines

2.1.2 Miscellaneous fodder plants

The leaves and other aerial parts of papaya, water hyacinth, Ipomea, sweet potato and many other plants, other than those specifically grown for fodder are used for these purposes. Water hyacinth abounds in the Philippines which could be a useful ingredient for moist feeds if first boiled to form a paste. The leaves of coffee which are low in protein but high in fiber are also available in the country. The relative nutrient composition of some fodder plants are summarized below.

2.1.3 Roots and tubers

1. Arrow roots (Maranta arundinacea1.) is grown in Batangas and Laguna. Many farmers in these two provinces are beginning to plant it under the coconut trees. High quality starch is extracted. Fine bittie from the residue is also used for hog and poultry feed.

2. Sweet potato (Ipomea batatas L.) is a root crop grown in the Philippines chiefly for human food. Sweet potato commonly called “camote” is loaded with carbohydrates and rich in carotene (provitamin A) but extremely low in protein and minerals, particularly calcium and phosphorus.

3. Cassava (Manihot escolenta Crantz) or tapioca is a good substitute for cereals. It is high in carbohydrates, but low in protein, fat and minerals. Cassava roots must be processed very carefully as they contain a glucoside, liminarin which is acted upon by an enzyme to liberate prussic acid. Sweet varieties with roots containing less than 0.01 percent prussic acid can be used raw for feeding. Dried cassava or cassava flour has practically the same feed value as yellow corn.

4. Taro (Colocasia esculenta L.) locally known as “gabi” is an excellent source of carbohydrates, vitamins and minerals.

5. Elephant yam (Amorphophallus campanulatus) is also known as “pongapong”. Cooked pongapong tuber is a highly digestible starch feed, but its protein, vitamin and mineral content is too low to make it a complete feed indicating the need to improve its nutrition value.

2.1.4 Cereals and cereal by-products

Ricebran was found to have higher protein content than the grain. It is also fairly high in fiber thus limiting its use in fish feeds. Rice is grown primarily for human consumption in the Philippines. It is a staple food of the Filipino people.

Maize (Zea mays L.) has been found to be fed successfully to fish. It is used in finely ground form as an energy component in compound feeds.

2.1.5 Oil cakes and oil meals

Coconut oil cakes and copra meal are by-products of the vegetable oil when extracted. The coconut (Cocos nucifera L.) and the oil palm nut are the most important sources among oil bearing fruits. These are abundant in the Philippines.

Coconut oil cake is widely available as a feed for fish and livestock in the country.

Soybean (Glycine max L.) Merr.). Soybean meal is also available in the country. It is an important oil seed crop but has a relatively low oil content (less than 1 percent) and high in protein. Soybean meal is a good source of essential amino acid and can be used as a substitute for more expensive fish meal.

2.1.6 Feeds of animal origin

1. African snail meal. The African snail known as Achatina fulica when cooked for 30 minutes, removed from its shell and used in hog rations produces satisfactory results without ill-effects on the hogs. Snail meal from the bodies of the African giant snail contains approximately 60 percent calcium, 8 percent phosphorus, 4.35 percent cystine on a dry basis.

2. Earthworm meal. The earthworm when dried or dehydrated, yields a protein content higher than those of conventional protein rich/ingredients such as fish meal, meat and bone meal and soybean meal.

3. Giant toad meal. The giant toad meal which contains 61.63 percent crude protein has been found to be an excellent substitute for fish meal. The toad meal is prepared by drying the meat then cooking and grinding.

4. Fish silage. The acid ensilage of fish as an alternative animal feed in place of the conventional fish meal has been suggested by many scientists. In recent years, attention has been concentrated in fish silage as a means of utilizing fish waste and fish offals in situation where fish meal production is inappropriate. Fish silage is prepared through fermentation using formic acid (CH²O²). The fish are cut, ground or chopped. For every 100 kilos of fish materials, add about two kilos of 3 percent formic acid solution.

5. Feather meal. Hydrolized feather meal is the product resulting from the treatment under pressure of clean, undecomposed feathers from the slaughtered poultry free from additives, and/or accelerators. Feather meal is a good substitute for soybean meal.

6. Maggot meal. Maggots (larvae of housefly) when dried to 7 percent moisture content contain 53 percent crude protein, 18 percent crude fat, 11 percent ash, 2 percent nitrogen-free-extract (NFE) and 3 840 Kcal ME/kg. A 10 percent maggot meal in a corn-soya base diet performed equally well or better than those fed preparations containing the same level of fish meal, meat and bone meal or soybean meal protein in terms of feed consumption.

7. Mussel (tahong) meal. The freshwater mussel known scientifically as Cristaria plicata (formerly identified as Anodonta woodiana) contains 62 percent crude protein on a dry weight basis.

2.1.7 Other feedstuffs

Some of these feedstuffs like mollasses or yeast and leaf protein concentrates are termed non-conventional feedstuffs. These are available in the Philippines and can be a good partial replacement for the more expensive cereal grains as an energy source.

Brewer's yeast is obtained as a residue from the country's beer breweries. The material has a higher feed value and contains more than twice as much protein on a dry weight basis. It is also a rich source of B-vitamins, but low in calcium.

2.2 Live or fresh natural feeds

The cultivation of Methanomonas spp. a bacterial protein among the single-celled proteins and the micro-algae for aquaculture feed has been considered for aquaculture feeding. Chlorella, Scenedesmus and Spirulina have been established as an excellent feed for larvae of many cultured species of fish on a moderate scale production through fertilization of the pond and water management.

3. FEEDS SUPPLIES

3.1 Raw materials supply

There are ingredients like ricebran, copra meal, ipil-ipil leaf meal and fish meal regularly available in sufficient quantities in the country. There is no need to buy large quantities for future use by storing them. The problem of long storage could ruin the feed ingredients. However, the cost of raw material vary from place to place. Table 1 shows the proximate analysis of some feedstuffs as given by the UPLB.

Table 1. Proximate analyses of available feedstuffs in the Philippines

Source: Castillo, L. S. and A. L. Gerpacio. 1979. Nutrient composition of some Philippine feedstuffs. UPLB Tech. Bull. 21, 4th ed. 117p.

3.2 Feed manufacturers

¹ Volume imported/year
² Average monthly production

3.3 Kinds of formulated feeds used in the Philippines

Various feeds formulations as tested and recommended based on their efficiency and cost for finfish culture (O. nilotica)

Formulation	Percent protein	Culture system	Proponent	Cost/kg	FCR
DIET 1
Ricebran (75%)	22.251	Cages	Guerrero	not given	-
Fish meal (25%)
DIET 2
Ricebran (75%)	21.251	Fishponds	BFAR, Tanay Research Station	not given	-
Fish meal (15%)
Soybean meal (10%)
with vitamin mineral premix
DIET 3
Ricebran (70%)	21.851	Fishponds	-do-	not given	-
Fish meal (15%)
Soybean meal (10%)
Ipil-ipil leaf meal (5%)
with vitamin-mineral premix
DIET 4
Ricebran (45%)	28.32	Cages	BFAR, Fish Propagation Division	6.00	1.1
Fish meal (48%)
Copra meal (5%)
Ipil-ipil leaf meal (2%)
with vitamin mineral premix
DIET 5
Ricebran (70%)	24.31	Cages	BFAR, Freshwater Aquaculture Development Training Center	not given	1.3
Fish meal (30%)
with vitamin mix
DIET 6
Ricebran (65%)	26.351	Cages	-do-	not given	1.5
Fish meal (35%) with
vitamin mix
DIET 7
Ricebran alone	12.3	Cages	Guerrero	not given	-
DIET 8
Fish meal (20%)	27	Cages	Pantastico and Baldia	not given	4
Ipil-ipil leaf meal (20%)
Ricebran (60%)
DIET 9
Ipil-ipil leaf meal (33.3%)	-	Cages	Pantastico and Baldia	not given	-
Ricebran (66.7%)
DIET 10
Fish meal (25%)	Cages	Guerrero	not given	1.7
Fine ricebran (75%)
DIET 11
Fish meal (25%)	Cages	Guerrero	not given	3.6
Ricebran (65%)
Copra meal (10%)

¹ Based on Proximate Analysis conducted by Castillo, L.S. and A. L. Gerpacio on the nutrient composition of some Philippine Feedstuffs. UPLB Tech. Bull. 21, 4th edition. 117 p., 1979.
² Based on Proximate Analysis conducted by BFAR, Fisheries Utilization Division.

Various feeds formulations as tested and recommended based on their efficiency and cost for shrimp culture

3.4 Trash fish and other raw materials of animal origin

This include blood, feather meal, poultry by-products meal, fish meal, meat meal, raw fish, fish oils, fish silage, shrimp meal and milk by-products. Animal protein is necessary to balance the amino acid and vitamin deficiencies in cereals and other plant products. These are believed to contain unidentified growth factors for some animals.

Trash fish is difficult to define because it differs from location to location in species composition. It consists of fish which are too small, too large, or disliked by consumer for consumption. In the Philippines, trash fish is available at the fish landing sites where they are bought at a much lower price of 10.00/kg. However, these are usually channelled to fish sauce and fish paste manufacture or used for fish meal production. Finfish farming in the country is mostly devoted to milkfish and tilapia. Seabass or grouper farming is still a very small aquaculture operation and trash fish supply as feeds is already felt a constraint. It is also for this reason that the culture of the catfish, Clarias did not prosper despite the availability of seeds through importation from Thailand or by artificial spawning.

4. FORMULATED FEEDS

The quality of feeds depends on such factors as satisfaction to the nutritional requirements of the prawn, palatability, allurement or attractability, stability, survival and growth performance, conversion efficiency, healthiness and cost effectiveness. In the past, farmers were concerned more of stability and growth. At present, farmers are more concerned of survival.

There are four major advantages in using formulated feeds for intensive aquaculture purposes. These are (a) uniformity with regard to quality; (b) nutrient balance for maximum growth effects; (c) adequate and easy application; and (d) generally lower cost.

4.1 Shrimp feeds

Protein is the most expensive ingredients in the ration but primarily responsible for growth. Younger prawns require more protein than mature ones, and Penaeus monodon juveniles require about 40 percent protein (Alava and Lim, 1982).

There is really no “ideal” formulation but rather a number of possible feed formulations that meet the nutritional needs of the prawn have been tried. The basic information needed in feed formulation is the nutrient requirements of the prawn. Two or more protein sources are better utilized than one source alone.

Example: When three or more feed ingredients are used, balance a prawn diet to contain 30 percent protein using the following ingredients:

Fish meal:

1 × 60 = 60
60 + 48/2 = 54% (Protein source)

Shrimp head:

1 × 48 = 48

Ricebran:

1 × 15 = 15
15 + 12/2 = 13.5% (Energy source)

Corn meal:

1 × 12 = 12

Protein source — 54%:

30%

Energy source — 13.5%:

4.1.1 Methods of feeding

Prawns are fed 8–10 percent of the biomass per day when they still weigh 1–10 g and decreased to 3–5 percent when they weigh more than 10 g. These are fed twice daily at about 0900 and 1600 hours in feeding trays. The shrimps are sampled for weight increase every two weeks or once a month and the new amount of feed to be given is recomputed. Mortality of stock is extrapolated at 10 percent, 20 percent, 30 percent and 40 percent for the first, second, third and fourth month, respectively.

4.2 Finfish feeds

In the Philippines, there are plenty of available high protein feedstuffs which are excellent fish feed ingredients. Tables 2 and 3 show the crude protein contents of some common feedstuffs and green roughages which may be used as fish feed ingredients.

Table 2. Crude protein (percentage) content of some common feedstuffs for fish diet¹

¹ Based on BAI Laboratory Analysis, US NRS (1979)

Table 3. Crude protein (percentage) content of some green roughages in the Philippines¹

¹ Nutrient composition of some Philippine Feedstuff.Tech. Bull. No. 21. A.L. Gerpacio and L.S.Castillo.

4.3 Situation of the fish feed industry

The commercial feed industry has only recently begun to produce formulated feeds for the aquaculture industry. Many fishponds are still utilizing indigenous feed sources and inputs such as algae and animal manure.

Area used for fishponds/shrimp farming

Source: After de Leon, 1985

With the assumption that 40 percent of fishponds use feeds, the total feed requirement of fishponds is 65 000 metric tons per year. Furthermore, assuming 8 percent of the total fishponds is devoted to shrimp farming, 13 000 mt/year constitute the total feed requirement of the shrimp industry in the Philippines. This is because, among the users of feeds in the fish industry, prawn farming has gained considerable attention. Domestic consumption of prawns grew by 319 percent from 7 000 kg in 1973 to 32 000 kg in 1983. Exporters also grew by 470 percent from 93 million in 1976 to 532 million in 1984.

In prawn growing, 95 percent utilizes the extensive culture while 2.8 percent and 2.0 percent uses semi-intensive and intensive culture techniques, respectively.

Assuming a one-hectare semi-intensive farm with a survival rate of 80 percent and a feed conversion ratio of 1.8, the following feeds are required:

Feed requirement in semi-intensive farming

Source: After de Leon, 1985

Competition of substitutes in the fish feed industry come in the form of natural feeds like “lab-lab”, chicken, cow and horse manure, and other agricultural by-products. The extent at which these natural feeds are used is dependent on whether extensive, semi-intensive and intensive farming is used. Extensive farming uses natural and supplementary feeds, semi-intensive utilizes pelleted supplementary feeds (or low cost feed), while intensive farming requires complete pelleted feed ration.

Feed formulation and application are considered at an experimental stage and technology is greatly dependent from foreign sources. Most farmers still depend on the natural nutrients of the ponds with the addition of low cost supplemental feeds like trash fish and agricultural waste products. It can be argued that the stage of the fishery feed industry goes hand in hand with the level of sophistication of fish farming in the Philippines.

At present, there are around eight producers of fish feeds in the country. This structure is classified as oligopolistic in nature where a small number of rival firms dominate the industry. Competition is largely on price and quality variables. Prices of feeds used particularly in prawn farming range from 30 to 32.

Price of prawn feeds

Type	Price ()
Starter	32.84
Grower	31.18
Finisher	30.58

US$1.00 = 20.00

4.4 Problems and issues

4.4.1 Raw material supply

The growth of the fish feed industry is hampered by the unavailability of feed supply due to raw material bottlenecks. The common feed ingredients include high quality fish meal, shrimp meal, squid meal, soybean meal, meat and bone meal, ipil-ipil meal, ricebran, flour, etc. Herein lies the problem of commercial aqua feed production. The special nutrient requirements especially for prawn feeds necessitates the use of imported raw materials which will comprise about 80 percent of the formulation and 90 percent of total costs. This is very much higher than the utilization or inclusion rates of commercial poultry and livestock feeds.

Moreover, raw materials are subject to tariff rates as high as 30 percent. This adds to the cost of local producers making his feed supply less competitive vis-a-vis foreign competition in countries like Taiwan.

4.4.2 Necessity of using feeds for large-scale production

The fish feed industry has to contend with a Filipino value system which is accustomed to traditional fish growing techniques that utilize minimal feeds or leave to ecology and natural food the continuous sustenance of fish. The traditional feeding strategy is appropriate in extensive farming and semi-extensive farming to a certain extent. A stocking density of 25 000 fry per hectare is still appropriate here. However, at higher stocking density additional feed is required to accommodate higher carrying capacities.

4.4.3 Quality and standards

Feeds produced by different firms have different feed conversion ratios which range from 1.2 to 1.8 variability can be explained by the product's life cycle. Since commercial feed is still at an infant stage, variation due to experimentation, technology and availability of raw materials is understandable. However, consumers are affected by this variability.

5. RECOMMEDATIONS

As to raw material sourcing, greater leeway should be provided to the industry in importing the necessary raw materials. This connotes timely access to raw materials at a competitive tariff rate.

In so far as credit availability to finance expansion is needed, loan should be made readily available through conduits which should reach farmers even in the remote areas of the country.

Information dissemination should be conducted to continuously impart to the farmers the benefits of using feeds. Farmers, as well as ordinary citizens, should be made aware of the potential of the export market for fish and prawn products. This will push the need for more feeds.

Lastly, there is a need to utilize appropriate technology for feeds considering the industry's dependence on foreign technology. Formulation should be adopted to Philippine feed requirements and conditions.

REFERENCES

Castillo, L.S. and A.L. Gerpacio. 1979 Nutrient composition of some Philippine feedstuffs. UPLB Tech. Bull. 21. 4th ed. Los Baños, Philippines. 117p.

de Leon, A. Status of the fish feed industry in the Philippines. Mimeographed paper.

Natividad, J.N. 1982 Fish diet formulation. Fisheries Newsletter Vol. XI, No.4. Oct.-Dec. 1982. ISSN 0115-2459.

New, M.B. Feed and feeding of fish and 1987 shrimp. ADCP/REP/87/26. UNDP/ FAO Rome, 1987.

Pascual, F.P. 1983 Nutrition and feeding of Penaeus monodon. SEAFDEC, Extension Manual. 3rd ed. June 1983. ISSN 0115-5369.

Santiago, C.B. Feed formulation, nutrition and feeding. LP/T/HO-2. Mimeographed.

Santiago, C.B. 1982 Artificial feeds and feeding of tilapia. Lecture presented at the International Training on Tilapia Culture in Freshwater. Mimeographed.

Santiago, C.B. 1986 An evaluation of formulated diets for Nile tilapia fingerlings. Fish. Res. Journ. of the Phil. Vol. 11, Nos. 1 and 2, Jan.-Dec. 1986.

COUNTRY PAPER
(Singapore)

THE CURRENT STATUS AND TREND OF FINFISH AND
SHRIMP FEED DEVELOPMENT

by

R. Chou¹

1. INTRODUCTION

Nutrition and feed are fundamental to most aquaculture practices and it is recognized that formulated feeds are required to increase productivity of cultured species, as is the case for livestock husbandry. In Singapore, farmed fish are cultured in netcages on floating farms located in the Johor Straits. There are, to date (1988), 70 floating fish farms covering 37 hectares (ha) of the 100 ha of available farming area in Singapore. The farms are located in areas off Pulau Ubin, Serangoon, Punggol (East Johor Strait) and Lim Chu Kang (West Johor Strait). Together with 190 ha of brackishwater and about 100 ha of freshwater ponds, they produce more than 1 percent of the total fish availability in Singapore.

Aquaculture production in 1987 was 2 058 metric tonnes (mt) or 13 percent of the local fish production of 15 310 mt. Of this, 1 825 mt (88.7 percent) and 75.7 mt (3.7 percent) were derived from seafarming and brackishwater aquaculture, respectively. The remaining 157 mt (7.6 percent) was from freshwater aquaculture.

The main species of finfish cultured in floating netcages are the spotted grouper, Epinephelus tauvina; seabass, Lates calcarifer and snappers, Lutjanus johni (golden snapper), L. malabaricus (red snapper). The main shellfish species cultured are the crustaceans, (banana shrimp, Penaeus merguiensis, mangrove crab, Scylla serrata, spiny lobster, Panulirus polyphagus) and molluscs (green mussel, Perna viridis).

Banana shrimp is also cultured semi-intensively in earthen ponds of which there are now 190 ha because of rapid land development and competition in usage. Nearly all of brackishwater production (75.7 mt in 1987) has been banana shrimp.

The Chinese and common carp (bighead carp, Aristichthys nobilis, common carp, Cyprinus carpio), lampam jawa (Puntius gonionotus), red tilapia (Oreochromis niloticus), hybrid, toman and aruan (Channa micropeltis, Channa channa) and marble goby (Oxyeleotris marmorata) are the main species of freshwater fish captured in earthen ponds.

With the exception of the green mussel which is a filter feeder, all the other cultured species require feeding. Trash fish feed is mainly used for the finfish and crustaceans like mangrove crab and lobster.

About 4 000 mt/annum of trash fish are available as feed for cultured fish in terms of quality and species. In addition, a supplementary source of freshly caught trash fish is available from palisade fishing traps (“kelong”), especially those within the proximity of floating fish farms. In 1987, 893 mt of trash fish was caught by the 31 “kelong” of the East and West Johor Straits.

Dry pelleted feeds are available for shrimp (mainly for tiger shrimp, P. monodon and used for banana shrimp), carps and tilapia. Carp feed is also commonly fed to other omnivorous species like the tilapia. No proven commercial dry feeds exist for the other species.

¹ Senior Primary Production Officer, Marine Aquaculture Section, Nutrition and Production Unit, Primary Production Department, 8th Storey, Maxwell Road, Singapore 0106

2. CURRENT STATUS OF FEED DEVELOPMENT

2.1 Shrimp larval stage

In the hatchery situation, live food such as diatoms (Skeletonema costatum) and brine shrimp nauplii are still used. As in finfish hatcheries, the production and manual application of live foods is labour-intensive and also demands close management especially since production can be affected by weather fluctuations.

The feasibility of using commercially available microfeeds needs to be explored to ease the problems mentioned, since these feeds can be applied by automatic feeders. They may be used solely or in combination with live food, depending on the economics of the situation and on nutritional viability. Microparticulate and encapsulated feeds produced by Japan and the United Kingdom for tiger shrimp larvae have still to be verified nutritionally and on economic terms. Feeding protocols and the use of automation have still to be established under local conditions.

2.2 Grow-out stage

No commercial feeds exist for the banana shrimp which is the only species cultured in significant quantity in Singapore. Farmers have since resorted to using the commercially available tiger shrimp feeds which are economical to use. Shrimp growth and feed cost may be improved with adequate banana shrimp feeds. Minced trash fish is also being used especially in floating netcages. Farmers culturing shrimp in ponds prefer dry pelleted feeds as trash fish is likely to pollute the water which is exchanged intermittently, usually according to tidal conditions, while it is continually changed in the floating netcage system.

The government has been looking into the development of suitable grow-out feeds for banana and tiger shrimps as well as the kuruma shrimp (P. japonicus) with the private sector since 1986. Several formulations that have commercial potential have since been developed. It is expected that the use of dry pelleted feed would be the norm in intensive shrimp culture.

2.3 Finfish larval stage

At present, all stages of fish under culture rely on natural feed. Larvae and young fry on live food such as rotifers (Brachionus plicatilis), brine shrimp (Artemia salina) nauplii and cladocerans (Moina macrura, Daphnia magna), depending on whether they are marine or freshwater species.

Microfeeds that are commercially available for finfish are either not designed to suit the nutritional requirements of locally cultured fish or not yet proven. For example, commercial microparticulate feed for the sea bream (Pagrus major) appears to be unsuitable for seabass larvae.

Government's research and development continues presently on the assay of such available commercial and also test fish larval microfeeds on seabass larvae, and the establishment of an appropriate feeding protocol using automatic feeders.

2.4 Nursery and grow-out stages

Nursery and grow-out stages are fed on trash fish with the exception of tilapia and carp where dry feeds are available. In certain instances, the farmer uses a semi-moist feed which is a mixture of dry supplement and trash fish to feed fish in their nursery and grow-out stages. This practice is becoming more popular at floating fish farms. Mixing minced trash fish with dry feed ingredients like fish meal, wheat or ricebran helps to extend the availability of the feed. Care should be taken to see that microingredients are included to prevent nutritional deficiency and a binder, usually starch. The method of preparation of such semi-moist feeds is simple, and is by hand-pressing or passing through a slow grinder. The quality of such feeds, if made daily can be excellent. Poorly bound feeds such as those without an adequate binder can, however, result in considerable feed loss when introduced into the water.

The use of trash fish as feed has the inherent danger of introducing into the environment pathogenic bacteria and other infectious disease organisms. Moreover, supply and quality of the trash fish can be inconsistent, depending on the seasons and on transport and storage conditions. Supply is limited especially during the monsoon seasons when fishing effort is curtailed.

Nutritionally, adequate and field proven dry pelleted feeds for commercially farmed tropical food fish are not presently available for both nursery and grow-out stages. Basic nutritional requirement and feed development studies are undertaken by the government with a view of eventually establishing several commercially viable formulations for transfer to the commercial sector. At the same time, field and controlled studies are on-going to establish an automated feeding protocol for farming fish in floating netcage systems.

To date, controlled studies into the dietary protein and lipid requirements of the grouper and seabass have shown that the optimal is around 45 percent (dietary crude protein) and 8 percent lipid (ether extractable fat) for the grouper (PPD, unpublished) and 40–45 percent (dietary crude protein) for the seabass (paper presented at this Workshop) in their early grow-out stage (50–70 g initial mean weight and 200 g final meal weight).

3. TREND IN FEED DEVELOPMENT FOR SHRIMP AND FINFISH

3.1 Larval stage

The trend is towards the use of live food produced under indoor controlled conditions, the use of planktonic live food collected and concentrated from the sea by special equipment (plankton collectors) and also supplementation by microfeeds that have been formulated to suit the nutritional needs of larvae. Such feeds could eventually be produced locally, although initially, the preferred alternative would be to assay and confirm the feasibility (from the nutritional and economical point of view), of using the commercially available microfeeds. The aim of this approach is to facilitate the intensification of larval production, simplify its operational procedures and cut down on expensive labour in maintaining larval cultures and the production of live food. This has also been the trend in Japan and France where significant advancements in aquaculture technology have been made.

The development and technology for locally formulated microparticulate feeds and their production will eventually have to be established to satisfy the demand that will be created because of the progression into large-scale and more controlled seed production for an expanding aquaculture industry.

3.2 Nursery and grow-out stages

The trend in feed development and feed use for Singapore should be compatible with the direction being taken for aquaculture development. With the introduction of large-scale and intensive farming systems that are both sea (coastal and open water) and shore-based, the trend in feed development is towards nutritionally adequate and economically feasible, locally available dry formulated feeds for the main species being cultured.

In the production phase (nursery and grow-out), larger amounts of dry, formulated feeds are required since this represents the exponential growth phase of the animal. The development and commercial production of such feeds is, therefore, of significance to the feedmilling industry, while the feeds have the advantage of being readily available, of consistent and controlled quality and can be disseminated by automatic feeding systems. Their success has been demonstrated especially in salmonid farming.

The government's efforts in developing initially the grow-out feeds for banana and tiger shrimps and the seabass are in keeping with the trend towards higher technology and intensive farming, where there is an anticipated need for specialized feeds like medicated ones for routine prophylaxis, pre-harvest feeds like those for colour intensification, finisher and maturation feeds, and broodstock maintenance feeds. Eventually, dry formulated feeds could be developed for regional use.

The strategy for this is likely an adaptation of technology that already exists in Japan, the USA and Europe for temperate fish and subtropical shrimp species. The government would like to gain the interest of overseas institutes and industries to adapt their feeds and to tests them locally.

4. SUMMARY

Mariculture is a rapidly growing sector of the regional aquaculture industry. The development of artificial feeds for shrimp and finfish in Singapore is, therefore, mainly on the cultured marine food fish species. As the seabass and banana shrimp are presently the most popularly farmed species, government research and development efforts in nutrition and feed development are directed towards establishing nutritionally adequate and economically feasible dry formulated feeds initially for the production phase which accounts for a significant amount. Feed also represents a substantial portion of production cost. It is, therefore, important to ensure that any feed developed is designed for the target species and its life stage. It is also in the interest of farmers to reduce dependance on trash fish whose supply and quality are unreliable.

As far as possible, the government would like to achieve the required standard for high technology fish farming through adaptation of existing information and practices. In the case of feed technology, it is expected that this will be through mutual gain transfers between Singapore and potential foreign investors with appropriate accreditation.

The use of live organisms as food for larvae in hatcheries is expected to continue, but under a closely managed and controlled situation. Microparticulate feeds could also be used as supplement provided they satisfy the nutritional requirements of larvae and are economical to use.

COUNTRY PAPER
(Thailand)

FISH FEEDS AND FEEDSTUFFS USED FOR AQUACULTURE IN THAILAND

by

Nanthiya Unprasert¹

1. INTRODUCTION

It is generally known that feed constitutes the major operating cost of intensive and semi-intensive aquaculture. The actual goal of aquaculture is to convert the low priced feed into the fish flesh which is the major protein food source of the people in Asian countries.

Thailand is a major agricultural producer in the ASEAN region. Large quantities of feed raw materials are produced and consumed each year. Estimated domestic consumption of feed in 1985 was in excess of 14 million tons (and the remainder accounted for duck). The country exports large quantities of feedstuffs ranging from high-valued fish meal to inexpensive tapioca chips. Although commercial fish farming in Thailand has been in existence as long as its livestock husbandry development, aquaculture has not kept up with similar feed development activities in the livestock industry. Feeding methods of most fishes cultured are still largely traditional based on empirical experience using trash fish, ricebran and broken rice. It was just in recent years that aquaculture became aware of the need for feed inputs to increase production per unit area. Since 1986, the expansion of shrimp culture along the coastal areas has evolved towards the intensive and semi-intensive systems; the need for compound feeds is in great demand. The commercial feed factories are automatically built up to fulfill the need of this venture. This circumstance might lead to the good starting point of aquatic feed development in Thailand.

2. FEED INGREDIENTS AVAILABLE IN THE COUNTRY

Thailand is considered self-sufficient in terms of feed ingredient supplies. About 90–95 percent of raw materials are locally available. Most of the feed ingredients are consumed by the terrestrial animals. As agro-industry in the country has grown up not only to support local consumption but also for the national foreign exchange incomes, the development of quality and quantity of raw material supplies is one of the components of national development plans.

2.1 Feedstuffs for aquaculture use

The feedstuffs for aquaculture are almost the same types used in livestocks but the composition of feeds and usages are very much different. Some of the feed ingredients used in aquaculture and their nutritional value are shown in Table 1.

2.1.1 Legumes

Most seeds of legumes have a great potential value as aquaculture feed ingredients in Thailand although many anti-nutritive factors limit their use as raw. With high protein content, low in lysine and methionine and contains amino acids profide, still the by-product of oil extraction or other by-products, they are suitable to be used as feed ingredients. The most important legumes used in the country are soybean meal, peanut meal, mungbean and some of the leaves and stems such as ipil-ipil leaf meal have also been used.

¹ Fishery Biologist, National Inland Fisheries Institute, Department of Fisheries, Ministry of Agriculture and Cooperatives, Rajadamnern Avenue, Bangkok, Thailand

Table 1. Common feedstuffs used for aquaculture diet formulations

1 No price obtained
* Protein content varies from 50–70 percent

2.1.2 Miscellaneous fodder plants

The leaves, stems and other parts of terrestrial and aquatic plants are also used. Due to low protein and low digestibility these stuffs are used only for some herbivorous species. Their mixture with some other ingredients are also considered as the low cost feed. These are utilized in order to get rid of aquatic weeds and increase the production of most herbivorous species in polyculture systems.

2.1.3 Roots and tubers

The use of these ingredients as source of carbohydrates is quite limited due to low digestibility. Aquatic animals which mostly consume them prefer high protein content feed. The amount of root crops in Thailand are supplied to the terrestrial animals. Cassava has been used because of its ability which increases the water stability of the diets formulated for aquaculture use.

2.1.4 Cereals and cereal by-products

Thailand is one of the countries in ASEAN that produces large amount of cereals which supply carbohydrates source to the world population. The cereals produced are plenty and commonly available all year round in stable quantity. Both the cereals and their by-products also contribute significant protein and lipid content in the aquaculture diets. These ingredients are considered the cheapest raw material and excellent source of some vitamins. By-products from grain milling and oil seed extraction industries constitute the second largest feed resources in the country. Ricebran is the principal by-product of the grain milling industry and available for use at any level of aquaculture operations.

2.1.5 Oil cake and oil meals

By-products from the oil seed extraction industry are next to fish meal, the most important protein source for feeds formulation. They include soybean meal, linseed meal, cotton seed meal, peanut meal, sesame meal and palm meal. In spite of the overall better quality, the first limiting amino acid of linseed and cotton seed is lysine, but with peanut meal, methionine and cystine are relatively more efficient with lysine standing second. Soybean proteins on the other hand, are probably the most complete of any of the plant seed proteins available. Since most of these feeds have a common efficiency in lysine and methionine that an upper limit of their usage in rations of animals where protein quality have to be considered. So far, the quantity of these ingredients are under competition with fish meal. Due to the insufficient amount of soybean meal, importation of this ingredient from other countries is necessary. One limiting factor in using these ingredients is the high price compared to the balance of amino acid profide and level of protein content in the fish meal. However, the usage of these ingredients are very acceptable in feed industry.

2.1.6 Feeds of animal origin

High protein feeds are a group of edible by-products of animal or fish origin. The balance of amino acid that is usually limited in the protein of plant source are more diverse in protein levels than any other protein category. There are several grades of fish meals due to differences in processing which result in products of distinctly different characteristics as feeds. Fish meal represents the most important feed source in the country. It also represents more than half the total value of all animal feedstuff exports. Of the 350 000 tons fish meal produced, one third is exported. Before 1987, fish meal consumption by the aquaculture industry is not significant. However, due to the rapidly increasing shrimp feeds required, the high protein quality of fish meal is in great demand. There is also trash fish usage for aquaculture in the country for Clarias, snakehead, sand goby, seabass and grouper culture but no estimation of amount is reported. It appears that about 300 tons of trash fish are used yearly for this purpose alone. Shrimp wastes, squid waste and meat meal are also used in the feeds.

2.2 Live or fresh natural feeds

Living organisms are usually utilized as aquatic larvae feed. Mass production of natural feeds have been achieved for years inspite of the seasonal and uncontrolled natural environment as one limiting factor. Natural feeds are still playing important roles on aquatic seed production. Even though some efforts have been tried to solve the problems on artificial feeds such as microencapsulated, microparticulated diets acceptability is found only in some species. Suitable live feeds still contribute to the success of larvae rearing. The live or fresh natural feeds are divided into fresh water organisms and marine organisms. Some species of these organisms are sufficient to harvest from natural sources such as mosquito larvae for feeding aquarium fishes.

Mass production of natural feeds used in hatcheries both freshwater and marine species cultured in Thailand is usually prepared by adding organic and chemical fertilizers in the culture media in order to provide the nutrient for their production. The dominant natural food encountered in Thailand is listed in Tables 2 and 3.

3. FEEDSTUFF SUPPLY (QUALITATIVE DATA)

3.1 Feedstuff supply

Most of the feedstuff supplies come from local agricultural products; only few items such as vitamins and food additives are imported. The main source of feedstuffs available in the country are reported annually as follows:

3.2 Feed manufacturing

Due to the adequate animal feedstuffs in the country, animal feedmilling is one of the fastest growing industries. About a hundred integrated feedmills are registered (Table 4). Nine large ones account for more than half of 14 million tons of compound feeds manufactured annually. The commercial sinking dry pelleted feed for catfish were introduced about 20 years ago but few resort to their use because of the high cost of feed compared to the market price of the fish. New efforts have been made by the feedmilling industry, with the introduction of floating-type pelleted feed. But the traditional feeding practices using fresh trash fish detract the farmers from using them even floating type feed conversion has been claimed as low as 1.5:1. This circumstance prevailed for such period of time which resulted to slow development of compound feeds in aquaculture. Just recently, farmers realized the convenience of feeding with the use of ready complete feed that the amount of using both dry pellet and floating pellet formulated feeds increased. A few years ago when the freshwater prawn and marine shrimp have been promoted and the seed supplies are adequate, the need for compounded feed rapidly increased and many feedmill industries expanded in both quality and quantity. New aquatic feedmills are established in 1986–1988. The Department of Fisheries is presently competing and analyzing actual data being collected. The number of feedmilling plants are increasing. It is estimated that about 16 large to medium size factories have produced shrimp feeds of about half full capacity at 15 000 ton/month. The supply of shrimp feeds are still inadequate due to the rapidly increasing demand.

Table 2. Important species of freshwater natural food organisms

Table 3. Important species of marine natural food organisms and consumer

Table 4. List of fish feed factories
in Thailand

3.3 Kinds of formulated feeds, nutrient quality cost/kg and feed conversion efficiency

Formulated feeds are processed involving the procurement of raw feed ingredients, mixing of the ingredient in the right proportions at least cost formulations and achieving the final objective of a balanced diet to promote good aquatic animal growth performance. Since the processing technology for aquatic feeds are considered much more complicated than that of terrestrial animal feeds, a special appropriate technology is highly required. The important species such as Clarias, Puntius, Pangasius, tilapia, carp, Macrobrachium, Penaeus, seabass and other ornamental fishes have been cultured with compound feeds. Most of them are secret formulaes except the ones promoted from the Department of Fisheries. Several practical feeds are formulated at different levels of basic knowledge and experience of farmers in order to make lowest cost of feeds. Most of the feedmills produce commercial “closed” formulated feeds. A summary of the kinds of formulated feeds and their details are shown on Tables 5 and 6.

Table 5. Types of feeds produced and utilized in the country

+ Available
- Not available

Table 6. The proximate nutritional value, cost and feed conversion rate of the formulated feed in the practical uses

4. FORMULATED FEEDS

4.1 Shrimp feeds

There are several shrimp feeds formulated for different levels of culture. This is because of the differences of requirements due to the stocking rate, the natural food available, the production expected and the level of knowledge on feed requirement of aquatic animals. Some known formulations are shown on Tables 7 and 8 for examples.

Table 7. Feed formula for P. monodon

Table 8. Shrimp feeds using trash fish as the major component

4.2 Finfish feeds

The species of finfish cultured is divided into three kinds such as herbivorous, omnivorous and carnivorous fishes. Feeds are not formulated according to the requirement but by the price of the product at the end of the culture. Some feed combinations made are shown in Tables 9 and 10.

Table 9. Feeds for herbivorous species such as carps and catfish

Table 10. Feeds formulated for fry or carnivorous species

The feed formulation above are according to the culture system, fish age, environmental condition, price of the product, cost of the feed at the moment and availability of the local ingredients. More than half of the feeds produced by feedmills are mixed and consumed by the fish farmers depending on their experience and technology transfer from the government.

5. PROBLEMS AND CONSTRAINTS

5.1 Most of the efforts to increase aquatic animal production in both quality and quantity went into seed supplies; very limited funds are contributed to studies on aquatic animal nutrition requirements and fish feed technology.

5.2 The nutritional requirement and feed technologies developed in the temperate countries are not entirely appropriate to the need of the developing countries for tropical species.

5.3 Most of the formulations for aquatic animal feeds are based on experiences from land animals. Very few of the fish nutrition and fish feed technology exist. The lack of research work in this field reflect the slow process of development.

5.4 The study on this subject is complicated and special instruments are required; government budget alone is not enough to cover the need at the moment. The assistance of international agencies to enhance research activity would promote better development.

5.5 Many species of fish and shrimps need to be studied and the factors involved in the system of culture need to be standardized.

5.6 The high price of formulated feeds for some species are not economically appropriate for commercial application. Studies on some other waste products need to be undertaken to substitute the high cost feed ingredients.

6. RECOMMENDATIONS

The study of nutritional requirement of the various tropical species for aquaculture use should be investigated. The methodology of the study also need to be standardized. Trained manpower in this field should be developed to carry out the research activities. The plan of development in this area should be organized in order to identify outputs and comply with the requirements of the aquaculture industry. Such studies need support with scientific instruments to detect the nutrient composition not only the proximate nutritional analysis but also the necessary trace elements which can be answered scientifically.

International organizations can greatly help to develop the quality product of protein source to mankind by contributing financial support in this type of research.

Thailand has plenty of raw materials which are not fully utilized specially the agricultural products and their wastes. These stuffs should be considered for conversion to utilize feeds in the most economical way.

From time to time the exchange of the knowledge and information in this field should be shared among the ASEAN members which has similar species of fish and shrimp culture systems. The researchers should also upgrade their work and produce quality outputs for the benefit and efficiency of aquaculture production.