REPORT
to the
GOVERNMENT OF SAUDI ARABIA

SAUDI ARABIA FUNDS-IN-TRUST FAO/UTFN/SAU/010/SAU September 1985

A report prepared for the
Fish Farming Centre Project

by

G. Cuzon
FAO Fish Feed Consultant

This report was prepared during the course of the project identified on the title page. The conclusions and recommendations given in the report are those considered appropriate at the time of its preparation. They may be modified in the light of further knowledge gained at subsequent stages of the project.

The designations employed and the presentation of the material in this document do not imply the expression of any opinion whatsoever on the part of the United Nations or the Food and Agriculture Organization of the United Nations concerning the legal or constitutional status of any country, territory or sea area, or concerning the delimitation of frontiers.

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 1985

Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the opinions, ideas, data or products presented at these locations, or guarantee the validity of the information provided. The sole purpose of links to non-FAO sites is to indicate further information available on related topics.

This electronic document has been scanned using optical character recognition (OCR) software. FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.

TABLE OF CONTENTS

1. INTRODUCTION

1.1 Purpose of the Mission

1.2 Terms of Reference

1.3 Schedule of the Mission

2. Background

2.1 Project Location and Facilities

2.2 Feeding Equipment, Feeds and Fish

3. FEED FORMULATION - AVAILABLE INGREDIENTS AND TESTS

4. RECOMMENDATIONS ON EQUIPMENT FOR FRY AND FINGERLING DIETS

5. DISCUSSION

6. RECOMMENDATIONS

Appendix 1: ITINERARY

Appendix 2: FISH FARMING CENTRE STAFF - MAY 1984

Appendix 3: REPORT ON MEETING AT THE FISH FARMING CENTRE TO DECIDE ON THE OPPORTUNITY OF A VISIT TO THE FEED MILL

Appendix 4: LIST OF AUTOMATIC FEEDERS

Appendix 5: LIST OF INGREDIENTS

LIST OF TABLES

1. RAW INGREDIENTS AVAILABLE FROM THE LOCAL FEED MILL WITH SPECIFICATIONS AND PRICES

2. COMPOSITION OF EXPERIMENTAL DIETS FOR SIGANID FINGERLINGS

1. INTRODUCTION

1.1 PURPOSE OF THE MISSION

The Food and Agriculture Organization of the United Nations has been consulting with the Institut francais de Recherche pour l'Exploitation de la Mer (IFREMER), Paris, regarding assistance in developing fish feeds and a feed mill at the Fish Farming Centre (FFC), north of Jeddah. Development of fish farming is hindered in many areas because of limitations in the availability of good quality feed. In this regard, assistance is needed in planning and installing a pilot unit for producing experimental feeds at the FFC.

An agreement between FAO and IFREMER Paris through its affiliate France Aquaculture was reached to assist the FFC in implementing a feed mill and providing information on fish feeds.

1.2 TERMS OF REFERENCE

As part of the operation of the project, FAO assigned Gerard Cuzon, an IFREMER Scientist, to assist the FFC in improving its fish feeds. The terms of reference of the consultancy were:

1. to conduct a survey of locally available feed ingredients that may be processed into fish feeds for Siganus rivulatus, Tilapia spilurus, etc.

2. to formulate and test improved feed formulas for S. rivulatus, T. spilurus, etc., based on such feedstuffs

3. to recommend equipment and machinery suitable for manufacturing such feeds for pilot fish-farming; to prepare a detailed list including technical characteristics, cost estimates, and recommended suppliers;

4. to advise on the facilities (including power) required for the efficient operation of the fish feeds units, including storage of feedstuffs, processing and storage of feeds and testing of feeds; to provide cost estimates

5. to train local counterparts in the above activities

6. to study and make recommendations regarding the operation of a small feed mill on the project site.

1.3 SCHEDULE OF THE MISSION

2. BACKGROUND

2.1 PROJECT LOCATION AND FACILITIES

The FFC is located some 60 km north of Jeddah with good asphalted roads and can be reached in 45 minutes drive from the city centre of Jeddah. Large-scale construction of building facilities is underway and presently six pre-fabricated building units are utilized for offices and housing of the technical staff and workers at the site. Three electric generators are supplying power (60 cycles, 220 Volts) to existing prefabs and nursery acclimatization tanks of the project. Seven big fibreglass circular tanks (10 m³) and ten rectangular raceways tanks (16 m³) to be installed are available at the project and are expected to be constructed before the first stocking in summer 1985. Four improvised concrete rectangular tanks are utilized for Tilapia breeding as a ready source of fry fingerlings for experimental tests in the existing water-based aquaculture facilities (fish cages).

Six units of semi-commercial size (5 × 5 × 3 m deep) fish cages and fifteen smaller units (2.5 × 2.5 × 3.0 m deep) of nursery experimental cages are presently utilized for culture experiments of Tilapia spilurus and Siganus rivulatus. Juveniles of siganid are obtained from catches along the shoreline lagoon of the Red Sea coast and stocked in the nursery cages, and are later grown to fingerlings and marketable size in experimental cages. Two units of motorized boats are used in a water-based aquaculture operation which are also ideal for fishpen construction.

2.2 FEEDING EQUIPMENT, FEEDS AND FISH

Previously, the project produced its own feed in cake form, disposed in plastic feeding trays according to the specifications of Lichatowich prepared in 1981. In September 1984, in order to cope with the increasing need of about 175 kg of feed per day, ingredients were transformed into pellet form through a local feed mill company. With new grow out facilities the daily amount of feeds would roughly reach 500 kg/day. The actual cost of pelleted feed with the new formula of 30% protein is SRls 1 300.00¹ per ton.

Improvised plastic feeding trays are used in feeding the fish in experimental cages. Also, all project staff are proposing to use automatic feeding machines in all five aquaculture systems (cages, fishpens, lived ponds, circular tanks and rectangular raceways), (Appendix 4).

Good cooperation exists between FFC and the local feed mill for the production of pelleted feed for both Tilapia and siganids, and the use of fish oil and available ingredients, rather than exotic compounds, provided a welcome alternative to the team regarding feed formulation.

During the consultancy, experiments in floating cages were conducted with Tilapia spirulus and Siganus rivulatus in polyculture. The pelleted feed, distributed in plastic feeding trays, is readily accepted by both species; siganids average 100 g which represents the market size and Tilapia average 70–80 g. The survival rate has not yet been determined. Within two months the stock will be harvested, and an estimate made on the food conversion ratio of the pelleted feed.

Observations have given fair indications on stomach repletion, and fat deposition which appeared critical with siganids. This observation will result in modifications of the present formula (see below).

Finally, a rapid survey of the market showed the selling price of rabbitfish to be SRls 17/kg for 100–120 individuals.

¹ Exchange: US$ 1.00 = Riyals 3.56

Table 1

RAW INGREDIENTS AVAILABLE FROM THE LOCAL
FEED MILL WITH SPECIFICATIONS AND PRICES

3. FEED FORMULATION - AVAILABLE INGREDIENTS AND TESTS

Several species are to be considered in addition to Tilapia and siganids - mullet, milkfish, grouper and shrimp. Such species should be reared in different structures: cages, raceways, pens or ponds and be fed either a complete diet or complemental feeds, according to the type of structure and the stage of development (fry, fingerlings, adults, broodstock) leading to different formulas (starter, grower and finisher).

The status of the feed is more or less a supplemental feed which is given to both species, from 5 g average to 100 g. The formula of the feed includes fish meal 10%, soya 25%, meat and bone meal 10%, barley 55%, traces of vitamins and 0.6% of binder; the analysis gives 30% crude protein, 8% lipids, 7% ashes, 4% fibre and 46% carbohydrates.

Constraints for linear programmes are: meat and bone meal ≤ 15%, soya ≥ 20% and barley <50% and the ingredients available. Millet, sesame, yeast, chicken manure, wheat bran could be added (see Table 1). For example millet can replace part of the barley and aminoacids, lysine and methionine used to maintain the level of both in the diet.

The following fish growth rates were observed: for siganids and Tilapia the 1983 results were quite good and the conversion ratio of the feed (in cake form) still fairly high.

Primarily, such an experiment should show if, with the introduction of wheat bran into the diet, siganids can grow as well as before and produce less mesenteric fat when increasing protein content and decreasing energy from carbohydrates. Wheat bran represents a good ingredient for fish feed and it could be available at the feed mill. Meanwhile, an attempt can be made to incorporate chicken manure, another ingredient available at the feed mill.

Apart from this aspect of ingredients and nutrient balance of the formula in order to improve efficiency and limit the cost of feeding, more sophisticated experiments on the protein energy ratio of the siganid diet could be tried (see Table 2).

Table 2

COMPOSITION OF EXPERIMENTAL DIETS
FOR SIGANID FINGERLINGS

Observations on the stomach content of fish caught from cages, made 4 hours after feeding, showed different results according to the species. Siganids presented an empty stomach and some coarse particles of vegetable protein inside the intestine plus a critical amount of mesenteric fat, especially when compared with wild animals. Tilapia presented a full stomach and a small amount of mesenteric fat.

In addition to these anatomic observations, it is noticed that from time to time some siganids in floating cages become black and lose their eyes (exophthalmia); and some infections have been related to Pseudomonas.

All these indications should lead to an improvement of the rations for both species, and if the Tilapia feed appears adequate, an attempt should be made to promote a complete diet for siganids when reducing the energy content (at least during 2 months before harvest), and vitamins and drugs which could be added should be reviewed.

Improvements with regard to the formula should be tested in an experimental structure to consist of 8 circular tanks (1.35 m3) and 5 g S. rivulatus at a stocking density of 100 per tank. This experiment should last 4 to 5 months in order to check thoroughly the fat deposit in fish, and the 4 diets proposed, including the actual diet, would present different levels of energy and proteins.

Finally, some aspects of the fineness of the ingredients of the diet could be improved and tested both on Tilapia and siganids in order to improve the digestibility of feeds; coarse particles of barley are noted inside the pellet even though it is ground at the factory through a 2mm mesh screen.

Aspects of vitamin content are also important, particularly regarding the nutrition of siganids, and a supplement of vitamin A and D through a good quality fish oil, together with an environment in vitamin E and Cholin Chloride is quite feasible. Vitamin C should be available to balance the vitamin mixture for marine species.

Technologically, it will be useful to test in the future different qualities of pellets: sinking versus floating, rehydratable pellets, and coated pellets with fish oil and vitamins.

Particle sizes also represent a major item. Currently the fish are fed crushed meal formulated into moist cakes. However, if the feed is pelleted, a better fish growth can be expected. The feed mill is producing 3 mm diameter pellets which are too large for the smaller fish when the pellets are hand-tossed. Crumbs would be more suitable but adequate equipments for fry and fingerlings diets can be purchased very easily to find the best solution.

4. RECOMMENDATIONS ON EQUIPMENT FOR
FRY AND FINGERLING DIETS

These comments result from a staff meeting at FFC concerning feed equipments. Many aspects have to be considered before deciding on feeding equipment:

• growing structure
• quality of feed, extended versus pelleted and both of which versus spaghetti pellets
• quantity of feed needed
• cost of equipment
• species to be raised
• proximity of an existing feed mill
• kitchen or industrial material available and some equipment between these two extremes
• other minor constraints

All these aspects have to be kept in mind and it is recommended to proceed step by step. Generally, small equipment is purchased and the production capacity is increased accordingly, and different technologies are tested in order to determine the most appropriate.

At the FFC, the feeding problem has already been approached on a pilot scale. Results are still underway, but this action has greatly contributed to solve present feeding problems at the Centre.

Additional equipment is necessary, primarily to cope with experimental tests which are to be carried out together with a more convenient fry feed production. Such equipment would cost approximately SRls 64 000 and should include:

• a mixer - 20 l capacity (extension to 40 l)
• a meat mincer
• a paste pelletizer (optimal equipment)
• a crusher
• a sealing machine

Two grinders (Europmill) are already in operation. Now the development of rearing techniques on jack fish and grouper on one side, and the future extension of facilities on the other need attention.

Such extensions should represent something like 5 to 6 ha of ponds and raceways, 1 ha of ponds, in addition to the 360 m2 of existing floating cages. Full production capacity is estimated at 1–1.5 t/day at certain periods or about 40–45 t/month (such figures should be checked and reviewed several times), but give an initial dimension to the feed equipment capacity. Such equipment should include a cooker extruder for those activities of the Centre focused mainly towards fish culture:

Rather than implementing an apparatus for a few kg/h of production, equipment to handle 100 kg/h should be selected and set up next to the fry feed production room, consisting of:

• an extruder Anderson, 4 ½ inches, or a BC 45 Creusot Loire

• a horizontal mixer Gondard, CPM or others - a quotation will be requested in order to choose between different makes

• a hammermill of medium capacity chosen between Gondard (T20), Sprout Waldron

• a fluid bed dryer, the model AWlO is available and follows on quite well the production capacity of the extruder Anderson 4 ½ inches but is operating in batches instead of on a continuous line

• a coater in order to have the capability to add oil, and particularly fish oil after extrusion

• weighing scales are already available but an additional infra-red scale could be purchased in order to measure pellet moisture content.

The design for such equipment is reported below and cost estimations do not include building construction. Rough estimates for total length of the building and height will be completed later at COP.

The feed mill line at a 100 kg/h capacity upward is detailed below.

Concerning equipment and facilities for the feed production on the site, quotations should be collected from several companies in order to have a precise idea of the price fluctuation for the same kind of equipment.

1. the extruder:
   Anderson 4 ½ inches Creusot Loire BC 45

2. the drier:
   AW 10 fluid bed drier

3. the mixer:
   Rapidex

4. the paste pelletizer:
   Kustner produced by Shindler/Sviac

Brand names are only given based on experience of their use in similar conditions in the COP Centre and which have given satisfactory results after several years of use. This implies no preference to any particular supplier. Moreoever, if equivalent machinery could be purchased locally, it is advisable to do so.

5. DISCUSSION

Several questions were answered during the consultancy. However, additional information is needed, and tests shoud be carried on by project personnel to see if modifications to the diet will support the highest growth rate of siganids and Tilapia, and still be economical. Locally occurring foods should be tested and food conversion efficiencies should be established for various formulas.

Short-term questions:

1) Which ingredients should be used in the ration for siganids and Tilapia?

Primarily, as is already the case, ingredients which are available locally, i.e., mainly those which enter the broiler's rations. But improvements could be obtained from the use of wheat bran. Poultry byproducts are also available but their use is less profitable, either due to the way of processing the diet (which requests a low amount of fat), or the nutritive quality itself, e.g., chicken manure should be tested before being incorporated into the actual formula.

2) Is additional feed equipment needed at the Centre?

“Yes”, and for the following reasons: an experimental phase can be conducted, not only with siganids and Tilapia but later with marine species and possibly shrimp, for producing small quantities of diets in order to be able to prepare different sizes of particles and to test pellets presenting a special physical characteristic (extruded versus pelleted for example, or rehydratable properties).

3) Would it be possible to continue the present arrangement with the feed mill?

“Yes”, assuming that the only facilities are the existing cages and one pen. But as soon as land-based facilities are in operation, the feed mill at the Centre should meet the need for all experimental feeds.

4) What about equipment for fry and fingerling production?

The present system of preparation is consuming a lot of manpower. Carefully selected equipment should solve the problem of how to prepare small size particles, especially when the hatchery will be operating.

5) What is the percentage of biomass per day to feed fish?

Many reports supply this kind of information. The percentage is progressively decreased with the growth of fish. But, due to special environmental conditions in the Red Sea, especially during summer (up to 42 ppt and 35°C), percentages should be adjusted to the local situation.

6) What about the use of automatic feeders?

These are recommended for siganids which are feeding all the time, and for Tilapia, and for marine species (even shrimp). It improves the growth rate and the feed conversion as long as the daily feeding amount is well established and the environmental conditions are constant during a certain period. It has the disadvantage, particularly with fish, to restrict visual observation.

Long-term questions:

7) Are more detailed studies on nutritional requirements likely to be profitable?

Some tests on amino-acids and vitamins should be carried out in experimental units where at least two replicates can be applied.

8) Is culture of siganids possible at an economical level?

The answer depends on the price of the feed, the conversion ratio and the price of fish on the market. The Saudi market can accept fish of 100–120 g average weight for a price of SRls 17/kg. A weight of 100 g could be obtained after 6 months, allowing two crops a year. Feed from the feed mill costs 1.3–1.5 SRls/kg which is quite a reasonable price compared to broiler diet (1.0 SRls/kg) for example. The only point to check thoroughly is the conversion ratio but even with a 3:1 ratio it still appears profitable to raise siganids in cages, from the feeding point of view, and compared with existing marine fish data.

6. RECOMMENDATIONS

Recommendations are as follows:

1. The Fish Farming Centre should assemble accurate figures on feed conversion ratios of pelleted feeds in the polyculture of siganids and Tilapia cultured in floating net cages at different stocking densities. The Centre staff should start testing improved formula based on a protein/energy ratio which could reduce the fat deposit for siganids; experimental structures should be tanks, or, if not available, floating net cages (as a preliminary trial).

2. Present cooperation with the feed mill should be maintained and a complete chart of locally available ingredients reviewed in order to produce least-cost formulated diets.

3. An exchange of information on results of growth experiments on siganids and Tilapia should be established between FFC and IFREMER/TAHITI to continue improvements.

4. A survey of local equipment should be started in order to compare with equipment proposed in the present study and find out the most economical solutions.

5. Some figures of cost of material should be prepared in order to complete the estimate of “nutrition” building. Laboratory equipment should not be needed due to the proximity of the analytical facilities of Radwa feed mill.

Appendix 1
ITINERARY

Appendix 2
FISH FARMING CENTRE STAFF - MAY 1984

Appendix 3
REPORT ON MEETING AT THE FISH FARMING CENTRE
TO DECIDE ON THE OPPORTUNITY OF A VISIT TO THE FEED MILL

This visit is scheduled in order to obtain background information on ingredients available for fish feed and particularly protein sources, vitamins, etc.

The discussion lead to the following assessments:

1. The Fish Farming Centre has no reason to produce large quantities of fish feed. How can the feed mill produce small batches of feed of less than 1 t?

2. The cooperation which is underway with Radwa feed mill is quite adequate at the present time. However, starting about May 1985 neither the FFC nor the feed mill with present equipment can produce the many test feeds needed. The best solution appears to be for the FFC to purchase equipment that can make small amounts of feed for smaller tests and Radwa feed mill make the greater amounts of feed needed for pilot growing tests.

3. The cost of feed made at the FFC for various tests should largely be disregarded. However, close attention should be given to have feed made at the feed mill within a cost range economically feasible for fish farmers.

4. At the end of the meeting, it was agreed that a visit to the Radwa feed mill would be useful.

Appendix 4
LIST OF AUTOMATIC FEEDERS

KEWERS MASKIN AB.

Rattvikswagen 178 A
S- 790 21 Bjursas
Sweden

SKRETTING T. A/S

P.O. Box 319
4001 Stavanger
Norway
Tel. (04) 58 60 00

FRANCE-AQUACULTURE

Small device for experimental tanks
24 Volts

SOLAR Powered Feeder

Fish Farm Design and Engineering Limited
Stronachullin Ardrisharg Argyll PA 308 ET
Scotland, UK

Demand Feeder

Appendix 5
LIST OF INGREDIENTS