1. INTRODUCTION AND TERMS OF REFERENCEThe Government of the People's Republic of China, assisted by the United Nations Development Programme and the Food and Agriculture Organization of the United Nations, are engaged in project CPR/88/077, Fisheries Development in Qinghai Province.
As part of the projects operations, FAO assigned Dr A.G.J. Tacon as Fish Feed Specialist Consultant from 2 October to 1 November 1990 with the following terms of reference:
Working closely with the coldwater fish culture specialist, he will assist with formulation and production of good quality trout feeds in Qinghai Province, using locally available ingredients and machinery. He will also advise on feeding of juvenile naked carp and prepare a mission report.
2. ITINERARY
Arrival Departure
Manila, Philippines 2.10.90
Beijing, China 2.10.90 4.10.90
Lanzhou 4.10.90 4.10.90
Xining 4.10.90 27.10.90
Lanzhou 27.10.90 28.10.90
Beijing 28.10.90 1.11.90
Manila, Philippines 1.11.90
3. COUNTERPART STAFF
Mr Yang Hongzhi (National Project Staff - Bureau of Aquatic Products) and Mr Wang Meng (Bureau of Aquatic Products - Xining) acted as interpreter and counterpart staff throughout the consultancy.
4. AGRICULTURAL FEED SURVEY
4.1 Feed resources
Despite its high elevation (1652–6860m) and remote location in Northwest China (Figure 1), Qinghai Province supports a healthy agriculture industry. The principal agricultural crops grown (expressed in tonnes/year for 1989) include wheat (706,000), barley (171,000), potatoes (110,000), rapeseed (101,000), pea (57,000) and broadbeans (52,500). Other agricultural crops which are grown in the Province include millet, oats, buckwheat, corn, hyacinth bean, mung bean, sorghum, sesame, groundnut, safflower, turnips, sugar beet, melons, and a wide variety of vegetables and fruits. Major secondary products arising from the processing of these crops (expressed in tonnes/year for 1989) include wheat flour (560,000), wheat bran (140,000), rapeseed meal (67,000), rapeseed oil (34,000), spent alcohol grains (from the distillery industry), and brewers grains (2,200 tonnes, wet basis). Figure 1 shows the geographical location of the major crop processing factories within the Province.
Coupled with the extensive grazing lands in the Province, these crops and their by-products in turn support a rapidly growing livestock industry. The major animal species farmed include sheep, cattle, pigs and poultry, and to a lesser extent goats, ducks, rabbits, mink and fish. Total farm animal meat production in 1988 was estimated to be 127,300 tonnes of which 36.7%, 32.3%, 29.9% and 1.2% was derived from sheep, cattle, pigs and poultry/other animal species, respectively. By contrast, in 1989 total aquaculture production was estimated to be only about 400 tonnes per annum (40% silver/bighead carp; 50% common/crucian carp and 10% grass carp).
In 1988 over 29 slaughter houses throughout the Province slaughtered a total of 2,771,500 sheep, 547,100 pigs and 501,900 cattle. The waste by-products arising from the slaughter houses in turn support eight major meat/bone/blood rendering plants. In 1989 it is estimated that 4,000 tonnes of fresh slaughter house waste (liver: lung:stomach, 25:20:40, w/w), 3000–5000 tonnes of dried bone meal, 100 tonnes of dried blood meal, and 100 tonnes of dried meat and bone meal was produced in the Province. Figure 1 shows the geographical location of the major slaughter houses and rendering plants in the Province.
4.2 Feed compounders
Since its inception in the early 1980's the animal feed manufacturing industry currently boasts a production of 90,000– 100,000 tonnes of compound animal feed within a total of twenty small to medium-scale (<1–5 tonnes/hour) factories in the Province (Figure 1). Over 95% of the feed produced is in mash form for pigs, poultry, cattle, sheep, and only a small portion is produced in pelleted form for rabbit, mink and shrimp; the latter being produced for export to coastal provinces within China. At present there is no commercial manufacture of compound fish feeds within the Province. 4.3 Feed availability, composition and cost Due to the early frosts and harsh winters within the Province the growing season for most agricultural crops is only about 7 to 8 months from March/April to September/October; harvesting of the major agricultural crops generally starting in August and ending by late October. Despite the relatively short growing season most cereal grains, oilseeds, green legumes, and their by-products (including brewers grains) can be purchased throughout the year from the Provincial capital, Xining. Similarly, although major slaughter houses only operate from September until December, visceral by-products (ie. liver, lung, stomach, intestine) and dried by-product meals (ie. meat and bone meal, bone meal, blood meal) can be purchased throughout the year from cold stores (within the major slaughter houses) and Xining, respectively. Other commonly used animal feed ingredients (ie. fishmeal, fish oil, feather meal, soybean meal, sunflower seed meal, cottonseed meal, groundnut meal, binders, antioxidants, and vitamins) are imported from other Provinces within China or from abroad (in the case of Peruvian fishmeal), but are available throughout the year in Xining. The proximate composition and cost of the major feed ingredients and compound animal feeds available with Qinghai Province is shown in Table 1. 5. PRESENT AQUACULTURE FEEDING STRATEGIES 5.1 Rainbow trout At present there is only one farm in Qinghai Province producing rainbow trout on a commercial scale. The trout farm is located below the Dong Da Tan reservoir at an altitude of 2960m and 81km east of Xining (Figure 1). Operated by the Department of Water Conservancy, Qinghai Provincial Government, the farm began operations in 1985, and since 1988 has produced approximately 2 tonnes of marketable fish (ca. >200g body weight; farm gate value of Yuan 16/kg). The fish growing cycle on the farm is reported to be approximately 2.5 to 3 years from egg to market size (mean water temperature 7 to 9°C, range -0.5 to 20°C). The farm is operated by five staff, including two fishery graduates.
The farm feeding strategy involves the manufacture of a moist pelleted ration on site using a simple motorised meat extruder.
Three formulations are produced for three different fish size groups (Table 2). Dry feed ingredients and fresh slaughter house wastes (liver, lung and blood) are purchased from Xining and Haiyan (5km from farm), respectively. Fresh slaughter house wastes are only available in Haiyan from the end of September to the end of October, and these are purchased in bulk (sufficient for one year's feed requirement), boiled on the farm for 10 minutes (blood) or 30 minutes (liver/lung), and then dried under the sun for about one week (blood) or several months (liver/lung), depending on the weather. The dried by-product meals are then ground to a particle size of 1–2mm using a local grinder and stored at ambient temperature. All diets are produced on a daily basis; starter diets first being prepared as 3mm moist pellets (ca. 25% water) and then sifted by hand to the desired feed particle size. In addition to the use of moist pelleted rations, fish are also fed with fresh fish (naked carp; Yuan 1.4/kg) from the local reservoir when available. Diet costs were reported to be Yuan 2.5/kg and Yuan 1.5/kg for the starter and production diets, respectively.
Fish are fed by hand using a fixed feeding rate; fry 5–8% body weight/day, 4–5 feedings/day; fingerlings 5% body weight/day, 3– 4 feedings/day; production/broodstock 1–3% body weight/day, 2–3 feedings/day. Although the farm quoted an overall food conversion ratio of 1.9, reported fish mortalities were high; mortality rates quoted were 50% from fertilized egg to 0.5g fish, 30% from 0.5 to 5g fish, 70% from 5 to 15g fish (last year, exception due to administrative problems), and 10–30% from 15g to market size. Although the exact cause of the fish mortalities is not known, it is thought to be diet-related (ie. opinion of the farm staff). Trout production costs were reported to be approximately Yuan 9.45/kg, of which 30% constituted feed costs, 25% labour, and 20% fingerling costs.
5.2 Carp
At present the carp farmer in Qinghai Province relies on a semi-intensive feeding strategy; fish growth being dependent upon a combination of natural pond food organisms (resulting from the fertilization of ponds with animal manures) and external supplementary feed inputs. Supplementary feeds commonly used by farmers include kitchen scraps, green vegetable wastes, wheat bran, oilseeds and soybean curd. Under these culture systems fish generally attain a market size of above 400g in about two years. According to the Aquatic Products Supply and Sale Company (a subsidiary of the Bureau of Aquatic Products in Xining) the government wholesale and market price (Yuan/kg, September 1990) of 1) common carp, 2) grass carp, 3) silver carp, 4) crucian carp and 5) naked carp is 1) 6.92 and 8.30, 2) 6.24 and 7.30, 3) 3.00 and 3.60, 4) 7.6 and 9.12, and 5) 2.30 and 2.70, respectively. By comparison, the government market price (Yuan/kg) of beef, lamb, pork, poultry, eggs, and milk is 4.96, 5.32, 5.50, 8.40, 5.28 and 1.00, respectively.
It is important to note here that the Bureau of Aquatic Products has recently (1990) started producing in-house pelleted feeds for use on its fingerling production carp farm in Xining. Although no precise dietary formulations were available, the diet is reported to contain meat and bone meal, rapeseed meal, wheat bran and wheat flour, but no mineral or vitamin premix. Pellets (2–3mm in diameter) are prepared using a Peihe Kelisiliao SLD-ZJ200 farm pelleter (production capacity - 210kg/h) and then dried under the sun before use. The diet is reported to contain 27% crude protein and is costed by farm staff at Yuan 0.7/kg. No details were available on the performance of fish fed this ration. However, past feeding trials conducted by Bureau staff with common carp in cages using an in-house produced dry pelleted diet have been disappointing; a 32.6% protein diet (containing 15% fishmeal, 30% soybean meal, 15% rapeseed meal, 30% wheat bran, 10% corn, and a carp vitamin and mineral supplement) resulting in a food conversion ratio of 3.
6. RECOMMENDED AQUACULTURE FEEDING STRATEGIES
6.1 Rainbow trout
6.1.1 Project objective
Immediate Objective No. 5 of the Project Document states:
To encourage the manufacture of good quality trout feeds by local feed mills in Qinghai Province.
Output 1:
Enhanced and locally produced moist and/or dry fish feed sufficient to produce 50 tonnes of market-sized rainbow trout per year.
Activities:
Assessment of locally available ingredients suitable for inclusion in trout diets, including seasonality, quality, quantity and price
Formulation of good quality diets
Organization of manufacture of diets, either in cooperation with a local pelleting mill or by installation of machinery at farm sites
Assistance to the manufacture of feeds by local feed mills as required and transport to the hatchery and on-growing units.
6.1.2 Feed formulation
Although fresh animal by-products such as liver and blood are available in limited quantities and could be used by a small-scale trout farmer (< 5 tonnes fish/year) within an in-house produced moist diet, a dry diet formulation and feeding regime is recommended for the Project fish farms.
Three dietary formulations are recommended for use within three distinct feed lines, namely starter, fingerling and production diets. Table 3 and Table 4 shows the recommended nutrient levels and dietary formulations for the three feed lines, respectively. The formulations are conservative in that emphasis has been placed on using high dietary inclusion levels of known quality ingredients (ie. such as fishmeal; Table 5) rather than experimenting with unknown cheaper alternatives such as rapeseed meal. For example, although oilseeds (ie. soybean meal, rapeseed meal) and animal by-product meals (ie. meat and bone meal, blood meal) can and have been successfully used at high dietary inclusion levels within practical salmonid rations (Table 6), their nutritional success is dependent upon the individual manufacturing process used to produce them. Thus, since the level of technology available in Qinghai Province to manufacture these ingredient sources is still in its infancy, and the proximate composition of these ingredient sources is highly variable, their inclusion level within the proposed diet lines has been kept to a minimum.
6.1.3 Feed manufacture
It is recommended that the Qinghai Province Mixed Feed-Processing Factory in Xining manufacture the three trout feed lines for the Project. The factory has considerable experience with the manufacture of shrimp rations (Table 1) and has the necessary pelleting equipment and resident technical expertise to undertake such a venture. Tables 4 and 7 show the recommendations for ingredient grinding and final crumble/pellet feed size, respectively. It is anticipated that approximately 2.5–3.5 tonnes of starter feed, 16–22 tonnes of fingerling feed, and 56–75 tonnes of production feed will have to be manufactured so as to meet the Project's production target of 50 tonnes of trout. This calculation is based on a farm food conversion ration of 1.5–2.0, and a survival from egg (700,000 individuals) to 5g fish of 50%, a survival of 71.4% from 5g to 50g fish, and a survival of 80% from 50g to 250g fish.
The feed mill's estimated manufacturing cost for the three feed lines is shown in Table 8. On the basis of these costings a letter of agreement was drawn up between the Bureau of Aquatic Products and the Qinghai Province Mixed Feeds Processing Factory, concerning the manufacture of the above feed lines for the Project (Appendix 1).
6.1.4 Feed storage
Since the manufactured diets are composed of perishable nutrients it is essential that the feed storage period on the farm prior to feeding be kept to a minimum and that adequate storage facilities are provided. Dry feed lines should be stored under clean dry ventilated conditions within a room with a concrete floor and walls (avoiding high humidity and direct sunlight), and used within two months of manufacture. Bags containing manufactured diets should be stored on wooden pallets and in such a manner so as to facilitate good air circulation between individual sacks, and should never be allowed to rest directly against the concrete floor or walls.
6.1.5 Feeding method
The success of a dry diet feeding regime is dependent not only on the formulation and manufacturing process used to produce the diet, but also on the method of presentation of the feed to the fish. Although the majority of large commercial trout farms in Europe normally use a fixed dietary feeding regime to administer their feed to the fish (Table 9), hand feeding to satiation is recommended for the Project fish farms. Fry should be fed at least 8–10 times per day, fingerlings 4–6 times per day, and larger fish 2–3 times per day, 7 days per week. The main advantage of hand feeding is that it is the fish that dictates how much it wants to eat (and not the feeding technician), and by so doing allows the farmer to keep a regular check on fish feeding behaviour and health, and water quality.
6.2 Naked carp
6.2.1 Project objective
Immediate Objective No. 3 of the Project Document states:
To establish artificial propagation technology for the production of fry and fingerlings of naked carp for stocking the lake.
Output 1:
Naked carp artificial propagation technology established.
Activities:
Artificial breeding trials
Larval and fry feed development
Nursing in artificial and/or natural water bodies
Fish stocking in the lake
6.2.2 Feeding strategy
The naked carp Gymnocypris przewalski prezewalski (Kessler) is omnivorous and demersal in feeding habit. In its natural habitat it has been found to consume both plant and animal matter, including Bacillariophyta, Rotatoria, Cladocera, Chlorophyta, Cyanophyta, Euglenophyta, Copepods, Ostracods, and Insecta. Compared with the major Chinese carps the naked carp is believed to be most similar to the common or crucian carp in feeding habit (Mr Yin Bai Cai/Mr Wang Ji Lin, personal communication).
Recent feeding trials (May/June 1990) conducted by Bureau staff at the Institute of Aquatic Products in Xining have shown that newly hatched naked carp larvae can be successfully reared on a traditional diet of boiled egg yolk and bread (supplemented with live zooplankton) with a survival of 70%. In view of this success and the vast wealth of Chinese expertise with carp it is not thought appropriate at this time to recommend any modification to this feeding regime. However, if time allows efforts should be given on the possible use of waste brewers grains from the nearby Hai Hua Brewery as a supplementary feed source for fingerling naked carp within the pond nursery phase prior to transfer to Lake Qinghai.
7. OTHER RECOMMENDATIONS
7.1 In-house training
It is strongly recommended that the Bureau of Aquatic Products assign one staff member to the Project on a full-time basis to cover all aspects of feed formulation, manufacture and feeding. Since there is no provision in the Project Document for specific training activities in this subject area, it is recommended that the Bureau provide funds for the in-house training of the selected individual at the Institute of Aquatic Products in Beijing. It is imperative that the Bureau recognise the importance of fish feeds and feeding in terms of staff training; food and feeding costs generally representing the largest single operating cost item of intensive fish farming operations.
7.2 Feed manufacturing equipment
It is recommended that the Project purchase a small-scale fish feed manufacturing plant. The feed plant would be used to train Project and Bureau staff, and would serve as an ideal demonstration unit for the Bureau in Qinghai Province. The feed plant should be purchased from within China for not more than US $ 20,000 (ie. Huada Machinery Factory, Guangdong Province - HD Brand Model 9KC-1000A). However, it must be made clear at the start that the Bureau should purchase its trout feed requirement for the Project during the first year of the trout farming operation from the Qinghai Province Mixed Feeds Processing Factory (Appendix 1). The feed plant should only be used to produce feeds for the Project after the staff have been sufficiently trained in fish feed formulation and nutrition in the opinion of the CTA. A prerequisite for the production of trout feeds by the above feed plant would be for the Bureau to first establish a modest analytical laboratory for the routine proximate analysis of feed ingredients and feed lines.
8. REFERENCES
Cho, C.Y., 1980 Recent advances in the diet formulation and the nutrition of salmonid fishes: Type of fat and its quality. Proceedings of the Conference for Canadian Feed Manufacturers 1980, Canadian Feed Industry Association, University of Guelph, Ontario, Canada, pp. 23–27
Tacon, A.G.J., 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, Brasilia, Brazil, 208p
