Annex 2
FIELD REPORT ON FEEDS AND FEEDING PRACTICES

1. BACKGROUND

The feed specialist consultant visited a total of 17 fish farms/reservoirs, three research/training centres and three fish feed/meal plants within the Provinces of Gilan, Mazandaran and Markazi. Throughout the mission and field visits the consultant was accompanied by Mr Chafur Mofateh, Chief of Aquatic Animal Nutrition within the Inland Fisheries and Aquaculture Department of Shilat. Due to time limitations it was not possible to visit the Shilat experimental shrimp culture facilities in Kollahi and Bushehr.

2. CURRENT AQUACULTURE FEEDING PRACTICES

Aquaculture feeding strategies were assessed on the basis of field interviews held with 12 private and 4 government fish farms within the Provinces of Gilan, Mazandaran and Markazi. The farms are listed below.

Farms and installations visited

Gilan Province

Fisheries Research Centre, Bandar Anzali (Shilat)
Ghazian Research Station, B. Anzali (Shilat; sturgeon)
Anzali Lagoon Research Station, B. Anzali (Shilat; grass carp)
Mapulek/Jafari Fish Farm (Private hatchery/grow-out - Chinese carp)
Hoshang Mohady Fish Farm (Private grow-out - Chinese carp)
Sad-e-Sangar (Dr Beheshti) Fish Farm (Shilat hatchery; sturgeon, mahi-sefid, pike-perch)
Golbaf/Samii Fish Farm (Private hatchery - Chinese carp)
Mirza Koochek Khan High Education Centre for Fisheries Science and Technology, Rasht (Shilat training centre)
Shahid Ansari Fish Farm, Rasht (Shilat hatchery - Chinese carp, mahi-sefid)
Shilat Fish Meal Plant, Bandar Anzali (Shilat)
Sefid Rud Fish Farm, Rasht (Ministry of Agriculture hatchery/grow-out Chinese carp)
Sefid Rud Animal Feed Factory, Rasht (Ministry of Agriculture)

Mazandaran Province

Berkeh Shoomal Co/Alaee Fish Farm, Behshahr (Private grow-out - Chinese carp)
Ghajar Khaill Fish Farm, Sari (Private grow-out - Chinese carp)
Shahid Rajaii Aquaculture Centre, Sari (Shilat hatchery - Chinese carp, mahi-sefid)
Nasr/Rahmatian Fish Farm, Sari (Private hatchery - Chinese carp)
Kossa Reservoir, 50km from Sari (Private reservoir - abandoned)
Bozorg Abandan Moziraj Reservoir, Babol (Private - Chinese carp)
Nasrelh Hashemi Fish Farm, Babol (Private grow-out - Chinese carp)
Ghovkessel Alla Shemgl Trout Farm (Private - rainbow trout)
Miar Trout Farm (Private - rainbow trout)
Barar Trout Farm (Private - rainbow trout)

Markazi Province

Chineh Co. Animal Feed Factory, 70km from Teheran (Shilat fish feed plant)
Karaj Mahi Sara Fish Farm, 50km from Teheran (Private hatchery/grow-out - rainbow trout)

1.1 Warm/temperate Water Fish Species

1.1.1 Chinese carp: Government hatcheries

At present a semi-intensive static water pond feeding strategy is employed for the production of silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella), bighead carp (Aristichthys nobilis) and common carp (Cyprinus carpio) within the government hatcheries visited. Fish larvae (3-day old, after yolk-sac absorption) are stocked directly (1 000 000 – 2 000 000 larvae/ha, mean 1 500 000 larvae/ha) into fertilized nursery ponds (0.5 – 3.0 ha in size, mean 1.0 ha) and fed on a combination of natural food organisms (produced within the pond through the application of chemical fertilizers and organic manures) and exogenously supplied supplementary feeds (natural and processed feed items). All carp fingerlings are produced in monoculture over a two to three month production cycle to a final body weight of 1 to 3 g and with a survival ranging from 10 to 70% (mean survival 50% after 3 months).

Nursery ponds are fertilized with a combination of organic manures (mainly cow manure, although poultry manure is sometimes used when available) and chemical fertilizers (urea, NH₄PO₄, NH₄NO₃ and NH₄SO₄); two weeks prior to stocking nursery ponds being fertilized with cow or poultry manure at a rate of 5–7 tons/ha and with chemical fertilizer at a rate of 70–100 kg/ha, and subsequently at 7 to 10-day intervals with 250–300 kg manure/ha and 70–100 kg chemical fertilizer/ha, so as to maintain a dissolved nutrient concentration of 0.2 mg/l NH₄PO₄, 0.3 mg/l NH₄NO₃ and 0.5mg/l of NH₄SO₄ throughout the three month production cycle. Manures and chemical fertilizers are generally applied by hand broadcasting (in dry or semi-dried form) from the pond bank or by gradual dissolution from suspended bags located at regular around the pond, respectively.

In addition to the consumption of the natural food organisms produced within the fertilized pond, the fish larvae also receive exogenous supplementary feed inputs, including chopped green fodder for the herbivorous grass carp (ie. grasses, aquatic macrophyte Azolla spp and/or alfalfa fed to excess) and an artificially compounded diet for the omnivorous common carp. The later is supplied by Shilat to all government hatcheries and consists of a range of different carp feed lines formulated by Shilat staff (Mr Chafur Mofateh) and manufactured under licence by the Chineh Co. Animal Feed Factory near Teheran. The formulation, crude protein content and cost of the various feed lines produced is shown in Table 1. On stocking, common carp larvae are reportedly fed the carp starter diets (SFC1 and SFC2) at a fixed feeding rate of 40% body weight/day within three feedings/day for the duration of fingerling production period. By contrast, common carp broodstock are fed the broodstock diets (BFC1 and BFC2) at a fixed rate of 1 5% body weight/day in one single feeding; the feeding rate being reduced to 2% body weight/day one week prior to spawning. However, no information was available concerning the growth performance and feed efficiency of fish fed the above mentioned carp rations, or concerning the costs of production, within the farms visited.

Although the above dietary feeding regime is thought to be typical of most Shilat operated hatcheries, it is also worth mentioning here the feeding regime employed by the Sefid Rud Fish Farm in Rasht (owned and operated by the Ministry of Agriculture). In this case, common carp are fed an in-house produced feed mash manufactured by the Sefid Rud Animal Husbandry Complex using ‘Kahl’ feed manufacturing equipment (10 ton/h pellet production capacity). The carp feed mash is reported to contain 17% crude protein and 4–5% lipid, and formulated as follows: barley 69%, soybean meal 1 5%, wheat 7%, wheat bran 4.6%, meat meal 2.2%, shell meal 1.2%, bone meal 1 %. The factory price and food conversion ratio (food fed/weight gain) of the diet is reported to be 200–250 Rial/kg and 3.5–4:1, respectively. Carp larvae are fed the ration only once daily at a fixed feeding rate of 10%, 25% and 40% body weight/day for the first, second and third month, respectively; the feeding rate being reduced to 25% body weight/day for grow-out of fingerlings stocked at 3 500–4 500 fish/ha.

Table 1

Formulation of Shilat fish feed lines produced under licence by Chineh Co. Animal Feed Factory

¹ Diet code: GFST - Grower Feed Salmon/Trout, KF - Kutum Feed, GFC - Grower Feed Carp, SFC1 -Starter Feed Carp #1, SFC2 -Starter Feed Carp #2, BFC1 - Broodstock Feed Carp #1, BFC2 -Broodstock Feed Carp #2

² Feed ingredient costs given by Chineh Co. Animal Feed Factory to be as follows: barley 1 20 R/kg, blood meal 800 R/kg, fish meal (kilka; 74–75% crude protein) 800 R/kg, Peruvian fish meal (65% crude protein; imported by Shilat from Peru) 1 300 R/kg, meat meal (40–45% crude protein) 500R/kg, soybean meal (44% crude protein; imported by Shilat from Argentina) 450 R/kg, wheat 150 R/kg, beet molasses 85 R/kg, Dicalcium phosphate (DCP) 400 R/kg, Multivitamin/mineral additive 1 100 R/kg, rice bran (11 – 14% crude protein, 10% lipid) 50 R/kg, Antioxidant (BHT) 5 000 R/kg, alfalfa 170 R/kg, cottonseed meal (30–31% crude protein, 4–8% lipid) 300 R/kg, sunflower seed cake 2 10 R/kg, wheat bran 100 R/kg. torula yeast 720 R/kg, poultry fat 170 R/kg; maize (imported) 250–270 R/kg, maize germ meal (24% crude protein) 300 R/kg

³ Poultry multivitamin and mineral additive formulated by Chineh Co. and reported to contain the following: thiamine, riboflavin, calcium pantothenate, nicotinic acid, pyridoxine, folic acid, cyanocobalamin, biotin, choline chloride, vitamin E, vitamin D3, vitamin A, vitamin K3 and zinc, Cobalt, Iodine, Manganese, Copper, Iron and Selenium

⁴ Iodized salt

⁵ Costings provided by Mr. Chafur Mofateh (Chief of Aquatic Animal Nutrition within the Inland Fisheries and Aquaculture Department of Shilat) and include a mixing/pelleting and transportation cost of Rials 12.5 – 25/kg and Rials 1 5/kg, respectively

1.1.2 Chinese carp: Private hatcheries and fish farms

The feeding regimes employed by the eight private Chinese carp farmers visited were generally related to the financial resources of the farmer, the species cultured, and the local availability of fertilizers and feeds. Consequently, while all of the farmers employed a semi-intensive static water pond feeding strategy, they varied widely in terms of the fish, fertilizer and feed management practices employed for fingerling or grow-out production, including;

Stocking density: larvae 600 000–3 000,000/ha (mean 1 500 000/ha), fingerlings (1 g) 200 000/ha, grow-out 2 000–6 000/ha (mean 4 000/ha), broodstock 250/ha (6–8 kg each; 1 500–2 000 kg/ha max)

Grow-out polyculture ratio: silver carp 40–65%, grass carp 10–15%, bighead carp 5–12%, common carp 18–40%

Chemical fertilization: 100% of farms visited, fertilization rate 100–200kg urea/NH₄PO₄/NH₄NO₃/ha/week

Manure fertilization: 100% of farms visited

Cow:poultry:duck manure: 75%: 12%: 12% of farms

Application method: 100% by broadcasting from side of pond

Application rate: Initial pond application of 2–5 t/ha prior to stocking and/or application of 25–75 kg/ha/day

Supplementary diet feeding: 100% of farms visited

-   Processed supplementary feeds: 100% of farms, of which 37% feed a single agricultural food item (66% rice bran, 33% whole wheat grain), 12% feed an in-house produced feed mash prepared from two agricultural food items (80:20 rice bran:cottonseed cake mixture), 12% feed a in-house produced carp feed mash prepared from three or more feed ingredients (formulation: barley and wheat meal 70%, soybean meal 5–6%, and fish meal 2–3%), 37% feed a commercial formulated carp feed mash (formulation 1: sunflower seed cake 22%, sesame seed meal 22%, wheat meal 44%, fish meal 1 2%;; formulation 2: maize meal.40%, rice bran 10–15%, wheat meal 10%, soybean meal 15%, fish meal 7%, minerals 0.5%) and 12% feed a spoiled commercial poultry feed mash
Application method and feeding rate: 100% by hand broadcasting over the pond surface 1–8 times/day at 1–15% common carp body weight/day Reported food conversion ratio (FCR): 1.3–5.0, mean 3.0

-   Live animal food supplements: 12% of farms, including the use of silk worm pupae during the summer months when available;

-   Green fodder and wastes: 88% of farms, including green grass, aquatic macrophytes (Azolla, Phragmites shoots), alfalfa and rice stems,
Application method and frequency: 100% by hand broadcasting over pond surface once every day or two days depending upon fish appetite and consumption

Reported raw material input costs in Rials/kg (R/kg): cow manure 5–20 R/kg (mean 10.6 R/kg), poultry manure 10 R/kg, chemical fertilizers 16–38 R/kg (mean 26 R/kg - government subsidized price; 40–75 R/kg free market price range), commercial carp feed mash 200–500 R/kg (mean 360 R/kg), wheat 150–200 R/kg, barley 130–160 R/k, imported Peruvian fish meal 1 400 R/kg, maize 200 R/kg, soybean meal 400–600 R/kg, rice bran 30–60 R/kg, sunflower seed cake 220 R/kg, sesame seed meal 350 R/kg, cottonseed cake 300 R/kg, kilka fish meal 500–600 R/kg, frozen kilka 120 R/kg, silk worm pupae 500 R/kg, poultry starter (22% crude protein) feed 333 R/kg (Chineh Co.) and poultry grower (18–19% crude protein) feed 318 R/kg (Chineh Co.)

Reported grinding/mixing and transportation costs by local millers: 10 R/kg and 20 R/kg, respectively.

Reported fish market value ex-farm: fingerlings (ca.10 g body weight, maximum free market value) silver carp and bighead carp 80 R/piece, grass carp 100 R/piece, and common carp 60 R/piece; grow-out market size (ca.0.8–1.4 kg body weight) silver carp and bighead carp 600–1 600 R/kg, grass carp 1 700–4 500 R/kg, and common carp 1 000 – 2 500 R/kg.

In contrast to Shilat operated farms, fingerlings produced and marketed from private farms tend to be larger averaging 10–15g in body weight compared with 1–2 g government-produced fingerlings; market preference for large sized fingerlings being due to their increased hardiness and decreased susceptibility to bird predation. The average reported net fish production within the grow-out farms visited ranged from 2.5–4 tons/ha/year, with a mean production of 3.1 tons/ha/year. The highest individual farm production was reported for the Nasrelh Hashemi fish farm whose production ranged from 3.6–4tons/ha/year; fingerlings (60–65% silver carp, 25% common carp, remainder grass carp) stocked at an initial density of 5 500 fish/ha within a 3-ha pond and having a reported a grow-out mortality of 10% over a six month production. The feeding strategy employed on this farm included pond fertilization with chemical fertilizers and organic manure (cow manure applied at an initial rate of 2 ton/ha prior to stocking and thereafter the same quantity distributed at weekly intervals for the duration of the culture cycle by hand application from the pond bank), the feeding of green fodder on a daily basis (grass or alfalfa depending upon availability) and the feeding of an in-house produced carp feed mash once daily at a fixed feeding rate of 5–6% body weight/day.

On the basis of the feed costs alone the cost of producing a 1kg increase in common carp biomass (within a six month production cycle) ranged from 1 92 Rials (using a rice bran/wheat mixture costing 50 R/kg, reported FCR 3.85) to 1 000 Rials (using a in-house produced carp feed mash costing 200 R/kg, reported FCR 5.0). In view of the reported market value for market sized common carp of 1 000 - 2 500 Rials it is evident that it would be much more economical for the farmer to use rice bran as a supplementary feed input for common carp. However, although the observed feeding strategies and reported fish production within the eight private carp farms visited was generally high, it is difficult to extrapolate these findings to the other farmers in the region. Clearly, an in-depth survey of the status of the private fish pond operators within the different provinces of Iran will have to be undertaken before an accurate assessment of the feeding strategies employed within the sector can be made.

1.1.3 Sturgeon (Acipenseridae) and mahi sefid (Rutilus frusii kutum); Government hatcheries

At present a live food feeding strategy is employed for the mass production of Sturgeon (Acipenser spp.) fingerlings within the Sad-e-Sangar (Dr Beheshti) Fish Farm. Fish larvae (3–5 day old, after yolk-sac absorption) are stocked directly into 2-m diameter concrete nursery rearing tanks and fed cultured live Daphnia (ranging from newly hatched 400 micron individuals to larger 600 micron individuals), newly hatched Artemia nauplii and cultured crushed/live oligochaete worms (Onchedreus albidos). The above feeding regime is maintained for 10 to 20 days until the sturgeon larvae reach a body weight of about 100 mg; fish survival from hatching to 100 mg was reported to be 60%. On reaching 100 mg the fry are stocked into fertilized nursery rearing ponds (4-ha sized ponds; initial fry stocking density 70 000/ha) where they are reared for a further 30–45 days until they reach the targeted river restocking stocking size of about 3 grams. Prior to stocking the nursery rearing ponds are fertilized with cow manure at an initial rate of 5 tons/ha and subsequently with the same quantity distributed over the 30–45-day production period depending upon water fertility. In addition, the nursery ponds are fertilized with chemical fertilizers (urea, NH₄PO₄, NH₄NO₃) at an initial rate of 400 kg/ha (urea) and thereafter at two weekly intervals in liquid form (25kg/ha NH₄PO₄) depending upon climate and water fertility. It is important to note that no exogenous supplementary feed inputs are provided during the pond rearing phase; mean fish survival during the pond nursery rearing phase was reported to be 60–65%.

It is important to mention here that experimental feeding trials have been conducted for the past three years by the staff of the Sad-e-Sangar fish farm with juvenile sturgeon fed in-house produced pelleted fish feeds; experimental pelleted feeds manufactured using a motorised kitchen meat mincer (after. cooking in water for 30 minutes) and the resultant pelleted diets tested with fingerling/juvenile sturgeon within indoor fibre-glass rearing tanks. The formulation of the diet currently being tested by the farm was given as fish meal (kilka) 20%, fresh kilka flesh 1 5%, soybean meal 20%, cooked spleen 5%, milk powder to be 800 Rials/kg and 3.2, respectively. Similar experimental feeding trials with sturgeon have also been conducted at the Ghazian Research Station using a feeding combination of frozen whole fish (kilka) and live or dried Gammarus spp. (amphipod).

In contrast to the sturgeon larvae, newly hatched mahi sefid (also locally known as ‘kutum’) are fed directly on an artificial diet prepared from dried cows milk and soybean milk. The larvae, which are reported to be very hardy, are then stocked at high densities (ca. 1 000 000/ha) within fertilized earthen ponds and fed an artificial mahi sefid pelleted diet supplied by Shilat to all government hatcheries producing mahi sefid. The formulation, crude protein content and cost of the diet is shown in Table 1. However, no information was available concerning the feeding rate employed for this diet and concerning it's FCR for mahi sefid within tanks or earthen ponds.

2.2 Coldwater Fish Species

2.2.1 Rainbow trout: Private hatcheries and farms

All of the four private trout farms visited employed an artificial diet feeding regime based on the use of an imported commercial trout diet for fry and fingerlings (up to 40-g body weight) and an in-house produced moist pellet for grow-out and broodstock fish. The commercial trout starter diet is imported by Shilat from Lohmann Terernaehrung GmbH (Neufelder Str.24–28, 2190 Cuxhaven, Germany) and is sold to farmers at a subsidized cost varying from 860 Rials/kg for size 1 feed (0.2 to 0.7g fish, 50% crude protein and 14% lipid diet), 850 Rials/kg for size 2 feed (0.7 to 2.5g fish), 700 Rials/kg for size 3 feed (2.5 to 11g fish), to 600 Rails/kg for size 4 feed (11 to 40g fish, 48% crude protein and 15% lipid diet). In-house prepared moist pellets are manufactured on a daily basis by the farmers visited using simple motorised meat mincing equipment. The reported formulations employed by two of the trout farmers visited was given as follows:

Ghovkessel Alla Shemgl Trout Farm

-   Starter diet: kilka 70 kg, fish meal (Peruvian) 34 kg, soybean meal 35 kg, blood (wet, boiled) 40 kg, wheat meal 24 kg, wheat bran 17 kg, soybean oil 2 kg, dried milk 100 g, multivitamin premix for poultry 1 30 g and bread yeast 300 g

-   Grower diet: kilka 1 8 kg, fish meal (Peruvian) 1 8 kg, soybean meal 10 kg, blood (wet, boiled) 20 kg, wheat meal 6 kg, wheat bran 3 kg, rice bran 2 kg, soybean oil 2 kg, dried milk 150 g, multivitamin premix for poultry 50 g and bread yeast 300 g

Miar Trout Farm

-   Grower diet: fish meal 107 kg (Peruvian and/or kilka), soybean meal 58 kg, wheat meal 38 kg, blood (wet, boiled) 60 kg, rice bran 17 kg, German trout starter diet 5 kg, soybean oil 1 200 g, salt 350 g and multivitamin premix for poultry 250 g. The cost of the diet and of market sized rainbow trout was given as 2 500 Rials/kg and 4 500 Rials/kg, respectively. The diet was fed to fish three times daily and was reported to have a FCR of 2.

In addition to the above in-house feed formulations a dry pelleted grower trout diet is also produced by Chineh Co. Animal Feed Factory under licence from Shilat for distribution to government trout farms and interested private farmers at a subsidized price of 477–495 Rials/kg (Table 1).

3. FISH FEED MANUFACTURING INDUSTRY

The fish feed manufacturing industry in Iran is still in its infancy and is presently confined to five major feed mills employing conventional poultry feed manufacturing equipment and techniques. The feed mills are located in Teheran (Chineh Co. Animal Feed Factory; two government mills), Rasht (Sefid Rud Feed Mill; government), Sari (Gumbat Feed Mill) and Arak (Arak Feed Mill; private). It is estimated that the total fish feed production from these feed mills was about 5 000 tons in 1991; 80% in the form of carp feed mashes and pellets, and the remainder in the form of pelleted trout feeds.

At present all Shilat operated warmwater fish hatcheries are supplied with fish feed manufactured for Shilat under licence by the Chineh Co. Animal Feed Factory near Teheran. Three feed lines are currently produced for Shilat, namely feed lines for common carp (starter, grower and broodstock), rainbow/caspian trout (grower) and mahi sefid (fingerling). The formulations, composition and cost of the feed lines produced is shown in Table 1. Under an agreement between Shilat and the Chineh Co. Animal Feed Factory, Shilat provides the feed mill with the formulations for the above mentioned fish feed lines, several key feed ingredients at a subsidized cost, including imported fish meal (700 Rials/kg), imported soybean meal (460 Rials/kg), blood meal and meat meal, 3) and pays the feed mill 12.5–25 Rials/kg of fish feed produced (cost includes grinding, mixing and pelleting) and 15 Rials/kg feed for transportation to the farm. However, at present no information is provided by the Chineh Co. Animal Feed Factory to farmers concerning the management of fish feeds at the farm level, including suggested dietary feeding regimes and levels for different fish age groups and culture practices.

The Chineh Co. Animal Feed Factory was reported to be the first factory to produce fish feeds in Iran (animal and fish feed production commenced in 1978 and 1984, respectively) and in 1992 it is estimated that the factory will produce 50 000 tons of compound animal feed - 75% poultry feed, 15% dairy feed, and 5% fish feed. The total feed manufacturing capacity of the CPM pellet mill within the plant is reported to be about 200 tons/day of pelleted feed. However, Shilat has estimated the compound fish feed requirements in Iran to be approximately 30 000 tons for warmwater fish feed (ie. carps and mahi sefid), 1 500 tons for cold water fish feed (i.e. rainbow and Caspian trout) and 1 000 tons for government warmwater and coldwater fish farms (Mr Chafur Mofateh - personal communication).

At present no government legislation exists concerning quality control standards and guidelines for fish feed ingredients and manufactured fish feed lines within Iran. For example, at the time of this mission no working laboratory facilities existed at the Chineh Factory for undertaking the routine proximate analysis of feed ingredients and finished feed lines. However, it should be mentioned here that Mr Mofateh (Head of Aquaculture Nutrition within the Inland Fisheries and Aquaculture Department of Shilat), is currently undertaking a one week training programme (5–1 2 October 1992) with Lohmann Terernaehrung GmbH in Germany concerning commercial fish feed manufacturing technology.

4. DEVELOPMENT CONSTRAINTS

4.1 Government Constraints

On the basis of the aquaculture feeding practices observed within the Shilat-operated fish farms visited and the discussions held with Shilat staff the following development constraints were identified:

-   lack of trained and experienced government staff in aquaculture nutrition and feeding, and in particular with experience in semi-intensive pond feeding strategies;

-   lack of up-to-date information concerning aquaculture nutrition and intensive/semi-intensive feeding techniques for distribution to provincial offices and farmers;

-   lack of a government extension service trained in the use and implementation of appropriate intensive/semi-intensive aquaculture feeding techniques;

-   lack of standardization of pond management strategies, and in particular pond fertilization and supplementary feed management strategies, within the Shilat operated seed production centres;

-   lack of information concerning the fertilizer and feed resources of the individual provinces within Iran;

-   lack of information concerning the use of different semi-intensive fertilization and supplementary diet feeding strategies under Iranian field conditions within Shilat operated farms, and consequently the lack of technical information concerning optimal pond fertilization and supplementary feed management techniques for application to farmers, and

-   lack of information concerning food/feeding costs and the economics of seed production within the Shilat operated hatcheries.

4.2 Private Sector Constraints

On the basis of the aquaculture feeding practices observed within the private fish farms visited the following development constraints were identified:

-   lack of training and knowledge concerning appropriate fertilizer and feed application methods and compound feed manufacturing techniques;

-   lack of information from Shilat provincial field staff concerning modern (up-to-date) intensive/semi-intensive feeding techniques and pond management methods, including optimal fertilizer and feed application methods, and concerning composting and compound feed manufacture, and

-   lack of standardization of pond management methods, and in particular pond fertilization and supplementary feed management strategies, irrespective of fish species ratio and stocking density, pond size, and fertilizer/feed input.

5. RECOMMENDED FOLLOW-UP ACTIVITIES

5.1 Training

It is strongly recommended that an in-house training course be organized on fish feeds and feeding (including pond fertilization and composting techniques) for Shilat staff, including senior officers from Shilat Ho, officers from the government seed production centres and field officers/extensionists. It is essential that government staff be trained on all aspects of fish feed and feeding; food and feeding costs generally representing the largest single operating cost item of intensive and semi-intensive farming enterprises. In addition, it is also recommended that Shilat send at least one staff member for overseas training in fish nutrition and feed manufacture to M.Sc or Ph.D level.

On completion of the in-house training programme it is recommended that the trained senior staff members and extensionists organize short-term practical training programmes on fish feeds and feeding for the private farmers within their respective districts and so apply the up-to-date techniques and methods learnt from their in-house training programmes.

5.2 Agricultural Feed Survey

It is recommended that a detailed survey be conducted of the agricultural fertilizer and feed resources of Iran, including where the individual resources are geographically located, how much is available and when, who is currently using this resource and how, the composition and cost of this resource at source and with transportation, and information concerning the existing animal feed manufacturing sector within the country. The aim of this survey would be to assist farmers to develop their own aquaculture feeding strategies, increase fish production and maximise the utilization of available agricultural byproducts and so minimise the use of imported feed ingredients. Guidelines for conducting an agricultural feed survey are given in Tacon, Maciocci and Vinatea (1987), National agricultural feed surveys for aquaculture planning and development in Latin America and the Caribbean. 1. Guidelines FAO Field Document, Project GCP/RLA/075/ITA, Field Document No.1/E, Brasilia, Brazil, 11 p. A copy of the above document was left with Shilat (Mr Mofateh).

5.3 Improved On-farm Fertilization and Feed Management Practices

So as to increase the average fish pond yields from 3 to 5 tons/ha within Iran the following improvements are recommended.

Chemical fertilizers should be applied to fish ponds by either first dissolving in water prior to distribution or through gradual dissolution within a floating perforated canister, suspended perforated sack or by placing onto underwater raised wooden platforms. On no account should phosphate fertilizers be allowed to come into contact with the pond bottom as they will-be rapidly adsorbed by the soil particles, thus rendering the phosphate unavailable to the water column. It is essential that the fertilizer be applied in such a manner so as to facilitate complete dissolution over the entire pond surface; this is particularly important for the larger fish ponds (i.e. above 5 ha), and could be facilitated either by the use of existing water pumps or through boat application. On a general basis, chemical fertilization programmes should be targeted so as to maintain soluble nitrogen and orthophosphate at 0.95 mg N/l and 0.1–0.5 mg P/l, respectively. However, it should also be mentioned that the beneficial effect of using nitrogen-based fertilizers (ie. urea, nitrates) has met with variable results in many countries and may not be necessary within ponds where there is a high rate of N-fixation (i.e. most tropical fish ponds). Finally, it has to be said that no two ponds are alike and that a fertilization programme developed or recommended in one location may be totally unsuitable for another, and as such each farm or pond must be considered as being unique. Clearly, a range of different fertilization strategies and dosage levels should be tested within experimental production ponds so as to determine the optimal fertilization strategy and the economic benefit or not of the fertilization programme. A review of fertilization programmes employed in different parts of the world is given in Tacon (1988), The nutrition and feeding of farmed fish and shrimp - A training manual 3. Feeding methods. FAO Field Document, Project GCP/RLA/075/ITA, Field Document No.7/E, Brasilia, Brazil, 208p. A copy of this document was left with Shilat (Mr Mofateh).

Farmers should be encouraged to apply fresh organic manures to their ponds on a daily basis either through livestock integration or through dissolution and broadcasting over the entire pond water surface if maximum pond productivity and fish production is to be achieved. In general, manures should be added as frequently as possible (if available), at least daily, on a little and often basis. On a general basis, the maximum amount of manure that a pond can safely digest without undesirable anaerobic effects is about 100–200 kg manure dry weight/ha/day or 70–140 kg organic matter/ha/day (as reported in the literature). As a general rule the manuring rate can be computed as dry organic matter at 2–4% of the standing fish biomass daily (for review see Tacon, 1988).

Farmers should be trained in anaerobic/aerobic composting techniques so as to make use of existing agricultural by-products which are currently discarded or burnt, including rice straw, rice husk and water hyacinth. The advantage of composting is that agricultural by-products which would otherwise have little or no nutritional value to farmed fish could be nutritionally transformed and upgraded into a potentially usable commodity for aquaculture; either as an efficient pond fertilizer or a supplementary feed source through the growth of bacteria and invertebrate food organisms (for review see Tacon, 1988).

The success of a supplementary diet feeding programme depends upon the feeding regime (level and frequency) and feed application method employed. Consequently, as with the application of fertilizers and manures, supplementary feeds should be fed on a little and often basis over the entire pond water surface every day according to fish appetite by hand feeding or through the use of raised underwater feeding platforms/trays, floating feeding collars or bait-rod feeders. Similarly, in view of the low fish stocking densities employed by private farmers (<6 000 fish/ha) emphasis should be given on the use of simple low-cost agricultural by-products as supplementary feed inputs such as mill sweepings, rice bran, Azolla, composted rice straw and husks. Similarly, if supplementary feeds such as whole cereal grains are to be used (i.e. wheat, barley) they should first be germinated prior to feeding by soaking in water; germination facilitating the destruction of the anti-nutritional factors present and increasing the amino acid availability and vitamin content of the cereal grains.

In contrast to complete diet feeding, the formulation of a supplementary diet is dependent upon the standing crop (ie. total biomass) of fish present and the consequent availability of natural food organisms within the pond. For example, the literature reports that no difference was observed in the growth of common carp in earthen ponds when fed a cereal grain (sorghum) or a formulated pellet containing 22.5% protein up to a standing crop of 800 kg fish/ha or between a ration containing 22.5% protein and a ration containing 27.5% protein up to a standing crop of 1 400 kg/ha (for review see Tacon, 1988). In view of the above it is perhaps not surprising therefore that little or no difference was observed in the reported growth performance and production of common carp within the private farms visited whether fed rice bran costing 50 Rials/kg, a cereal grain costing 150 Rials/kg, or a commercially formulated carp diet costing 500 Rials/kg. Clearly, the nutritional and economic benefit of pelleted feeds will only be achieved if higher fish (common carp) stocking densities are employed. However, if higher fish stocking densities are to be employed (> 10,000 fish/ha) then ponds will have to be of a much smaller and more manageable size (<2ha) for maximum benefit to be gained from pelleted diet feeding regimes.

Although the pelleted feed lines produced for Shilat by the Chineh Co. Animal Feed Factory were generally found to be satisfactory, it is recommended that (1) all feed ingredients be first ground so as to pass through a 0.75-mm mesh screen (0.50-mm screen in the case of premixes and starter diets) prior to pelleting, (2) the level of imported feed ingredients such as Peruvian fish meal and Argentinean soybean meal be reduced or replaced by local kilka fish meal/torula yeast and sunflower/cottonseed meal, respectively, (3) the poultry premix currently used in dietary carp and trout formulations be upgraded to include ascorbic acid and inositol so that the overall vitamin levels are in accordance to the known dietary requirements of fish, (4) the protein content of the trout grower feed be increased to at least 45%, and (5) feeding tables and farm feed management guidelines be drawn up for the different feed lines produced by Chineh Co. for subsequent distribution to farmers using/purchasing their feeds. Recommended dietary nutrient levels for cold water and warm water fish are given in Tacon (1987), The nutrition and feeding of farmed fish and shrimp. A training manual 1. The essential nutrients. FAO Field Document, Project GCP/RLA/075/ITA, Field Document No.2/E, Brasilia, Brazil, 11 7p. A copy of this document was left with Shilat (Mr Mofateh).