|
||||||||||||||||
| Environment |
| Agriculture |
| Livestock |
| Fisheries |
| Soil & Water |
| Palm Tree |
| Statistics |
| Photo Album |
| SPS Agreement |
| Guidelines |
| Manufactures Guide |
| Organic Agriculture |
| Green Buildings |
|
||||||||||
Prepared By: Abstract Fish meal currently occupies the unique position of being the essential dietary feed ingredient for all industrially produced aquafeeds. The rapidly growing aquaculture and poultry industries in different parts of the world make the demand for fish meal steadily increasing and keep its price always high. An attempt was made at the Marine Resources Research Center (MRRC), Umm Al Qaiwain, U.A.E. to produce the fish meal indigenously from trash fish collected from fish market using a fish meal processor. Results of this experimental investigation indicated that about 24% of the fish meal could be produced from the total quantity (wet weight) of trash fish processed whereas 10% was bone fraction and the remaining 66% moisture content. A comparative study on the estimated cost indicated that locally produced fish meal was about 42% less expensive than the imported one. Satisfactory growth response was observed in two species of marine fish fed with feeds containing local fish meal as the main ingredient under outdoor pond culture. Introduction Aquaculture is playing an increasingly vital role in the world fishery production. Aquafeeds generally represent the largest single cost item of most semi - intensive and intensive farming operations because once an aquaculture species reaches the juvenile stage, the major expenses involved in culture is often associated with the need to provide suitable diet to the proper growth of the organism. Fish meal is a safe, natural and environmentally friendly ingredient, the need for the inclusion of which increasingly dominate the future diet formulation. Also the Omega - 3 fatty acids in the fish meal and fish oil impart natural immunity on the farmed fish reducing or eliminating the need for medication. Taylor (1997) demonstrated that even a reduction in oxygen supply with growing Sturgeon in tanks did not give adverse effects on those fish fed with Omega - 3 fatty acids. Pilarezyk (1995) is of the opinion that even the herbivorous fish appear to have a more robust immune system when fish oil is included in the diet. According to Chong 1992, the cost of feeds and feeding in aquafarms normally accounts between 30% and 60% of the total production cost. The major consumers of the fish meal and fish oil are the carnivorous fish species followed by marine shrimp and omnivorous fish species (Tacon, A.G.J. 1992). It is stated that about 20% of the total world supply of fish meal and fish oil would be consumed within aquafeeds by the year 2000 (Chamberlain, 1992; New, 1991; Wijkstrom and New, 1989; Pike, I.H; 1991). Estimates suggest that 840 and 1078 thousand tonnes of fish meal were used within aquafeeds within aquafeeds in 1991 and 1992 respectively (Springate and Gallimore, 1992; Pike, I.H; 1991). Although the market availability of the fishery products is usually limited, they are preferable to many of the substitutes as they are highly palatable, good dietary attractant having well balanced EAA (Essential Amino Acids) and EFA (Essential Fatty Acids) profiles for farmed fish (Tacon, A.G.J., 1993). At the Marine Resources Research Center (MRRC), since its inception fish feeds have been made with fish meal imported from far eastern countries. In recent years there has been a hike in the price in world market as also in freight charges. Often difficulties were encountered due to delay in receiving the consignment and also lack of proper storage facilities on arrival. Therefore an attempt was done to produce fish meal indigenously at MRRC using trash fish collected from Dubai Fish Market. This was found very useful and partly supplemented the requirement of fish meal at the center whenever enough quantity of trash fish was available from the fish market. Material and Methods Fish Meal Processor A fish meal processor (Fig 1) manufactured by Nakayasu Seisakusho, Japan (model K 24 C) is available at MRRC. This is a robust, simple machine, easy to operate and made of high quality steel. The huller length is 120 cm and diameter 80 cm. There are four pairs rollers fixed to the central shaft of the machine which is connected to a gear motor by a chain and pulley system. The gear reduces the RPM of the motor and when the motor is switched on, the rollers turn at a slow, constant speed (approximately 8 turns per minute) while the contents of the huller get mixed up. The motor could be operated in the reverse direction as well if required.
Trash Fish Trash fish is collected in plastic containers from Dubai Fish Market with the assistance from Dubai Municipality Health Inspectors. Usually the collection of fish is done at mid - morning time after the peak sale period. When enough quantity of fish collected, it is transported to MRRC by pick-up. Shells and other foreign objects (in case present) are removed from the trash fish. Species of fish as well as their percentage of composition by body weight are recorded. The total weight of the trash fish is also measured and recorded. Operation Procedure The fish meal processor is switched on and the trash fish is put in the huller slowly while the rollers are moving. The huller can hold up to 300 Kg. of fish. The fire system is also operated. After ascertaining the smooth working of the machine, the huller could be closed by pulling the shutter down. In about 4 - 5 hours' continuous operation, the contents would assume a paste - form. Another hours' operation might be required for the contents to get dry and reach powder state when all the moisture lost due to evaporation. Approximately 5 - 6 hours are required to make fish meal using this machine although it mainly depends on the composition of species in the trash fish. Certain species with high oil content take longer period compared to the species with less oil content. Once the contents are in dry, powder form, the heating system is switched off while the rollers are allowed to continue the operation for some more time so as to prevent formation of lumps due to coagulation that might happen when the warm fish meal cools down. The machine is then switched off, the shutter of the huller is opened and the huller is tilted to one side to empty the contents into a clean, dry tray. The end product contains fish meal, fragments of cartilages and crushed bones. A sieve with mesh size 1.5 mm is used to separate the fish meal from the solid portion (bone fraction) of the mixture. The weights of fish meal and bone fraction are measured separately and recorded. The loss in weight from the initial total weight is calculated which represents the moisture content. The fish meal is kept in packets to be preserved in a freezer at temperature below 0º C. Cost Assessment An attempt has also been made to assess the cost of production using this method by grouping the total expenditure into two categories: one for routine operation costs and the other for the investment costs. Routine operational cost includes those for electricity consumption, diesel, petrol, ice cubes and labour. Investment costs are mainly the cost of machine, housing, plastic trays and containers, sieves, freezer, etc. The production cost is estimated from these two categories of expenses, assuming that the investment charges are for 10-year operation period. The cost incurred for the production of fish meal calculated this way is compared with that of the imported fish meal from abroad. The quality assessment of the local made fish meal was carried out through chemical analysis. Table 2 which gives the results of the chemical analysis of local fish meal and imported fish meal indicates almost comparable crude protein levels. The fish feeds made at MRRC using the local made fish meal have been found to be well accepted by the farmed fish species. An experimental study was conducted stocking juveniles of rabbit fish (S. canaliculatus) and Seabream (Rhabdosargus safba) in an outdoor culture pond with running water system and feeding daily with 5 - 8 % local fish feed using local fish meal as the main ingredient. Biological parameters of these species are measured every month to assess the growth rate and the data are presented in Figs. 3 and 4 and discussed. Results and Discussions Production of Fish Meal Six operations of the Fish Meal Processor are conducted using the trash fish as raw material collected from the Dubai Fish Market on six days. The present study is based on the data obtained from these experimental trials (Table 1). The percentages of fish meal and bone fraction calculated for each observation are in comparable range although variations are formed at few times which could be attributed to the difference in the species composition of the trash fish treated. Average values indicated that fish meal contributed to about 24% while the bone fraction was approximately 10% of the total wet body weight of trash fish processed. However, the remaining 66% was the moisture lost during the operation. These results are shown in Fig. 2
An estimate on cost of production The cost of fish meal production is estimated and Table 1 cont. gives the particulars. At the rate of two operations per week on an average, the total operation cost is about Dh. 10,017/= per year while the annual investment cost amounts to about Dh. 2950/= with the assumption that the machineries and the housing would have a utility period of 10-years and the life time of the freezer is about 5 years. In case about 259 Kg. of trash fish is used each time, approximately 4500 Kg. of fish meal could be produced during the 75 operations per year and the cost of fish meal would be around Dh. 2/90 per Kg. The cost of imported fish meal from the far east countries is about Dh. 5/- per Kg. which indicates that the local made fish meal costs about 42% less. Quality Analsys Data on Chemical analyses carried out on samples of local made and imported fish meal are given in Table 3. the protein content for the local fish meal was 68.79% while that of imported fish meal was 70%. Accordingly to Tacon 1993, the recommended specification of protein level in fish meal and fish oil used for salmon aquafeeds in North America is more than 68%. However, the quality and value of fish meal depend mainly on the condition of raw material used, the method of manufacture and storage conditions. In general, fish meals possessing the highest nutritional value and eliciting the greatest growth response in carnivorous fish are those which have been processed from fresh, whole oily fish specifies and dried at low temperatures (FAO 1986; Hardy and Masumoto, 1991; Pike, 1991; Springate and gallimore, 1992, 1992 a) Efficiency of local fish meal as a fish feed ingredient The two fish species fed with feeds containing local fish meal as the main ingredient and reared in an out-door culture pond for about an year showed satisfactory growth rates. Rabbitfish S. canaliculatus of 12.5 cm fork length and 37 g. body weight grew to 22.7 cm fork length and 208.8 g. body weight during a culture period of about 11 months in the pond (Fig. 3) whereas Sea bream Rhabdasargus Sarba juveniles of 9.4 cm fork length and 16.8 g. body weight reached 18.8 cm fork length and 160.8 g. body weight during the same period (Fig. 4).
Acknowledgements The authors express their sincere thanks to H.E. Saeed Al Ragabani, the Minister of Agriculture and Fisheries and H.E. Rashid Mohamed Kalfan for their keen interest in the work and the officials of the Dubai Municipality for their co-operation and assistance in the collection of trash fish from the Dubai Fish Market. References
|
||||||||||
|