Research and technology in aquaculture and fish nutrition
should be developed on the basis and experience of agricultural research . Stimulation and cooperation by and between public and private sectors have
been unimaginably deep, wide and diverse, therefore making today's achievements
in agriculture possible. There will be a similar success in developing nutritive,
environmental and cost-effective diets for aquaculture if public and private
sector cooperation in fish nutrition research is implemented immediately and
on a lasting basis.
The development of efficient diets for aquaculture is a long-term process requiring
a great deal of nutrition research and experimentation by public and private
sectors. The nutrient requirements of the species of fish under study and the
digestibility of nutrients in the feed should be known before the formulation
of balanced diets for fish production is attempted. However, in most cases,
including domestic animals in earlier days, this information was, for many years,
unavailable. Production diets, on the other hand, are usually required immediately.
Furthermore, it is necessary to have some sort of practical test diets that
can support acceptable growth to investigate and obtain required information
through applied research.
Until a few years ago a high amount of protein, generally
39%, was contained in carp feeds, but now many companies reduced the content
of protein by using about 30 to 35% of protein in pellet feeds for final growout
carp, but some companies still use 39% protein in their feeds. For fry or fingerlings
of carp, the average content of protein is 42.3% and 39.5% in pellets and extruded
feeds, respectively.
Table
Showing Main nutrient composition of feeds for different fish species*
(Unit : %)
|
Fish species |
Type |
Nos. |
Protein |
Lipid |
Ash |
Fiber |
Ca |
P |
Flounder |
Extruded
pellets (EP) |
starter |
55.0 + |
6.0 + |
17.0 - |
2.5 - |
1.2 + |
2.7 - |
1~2 |
53.0 + |
6.0 + |
17.0 - |
3.5 - |
1.2 + |
2.7 - |
3~6 |
52.0 + |
7.0 + |
17.0 - |
4.0 - |
1.2 + |
2.7 - |
7~10 |
50.0 + |
7.0 + |
17.0 - |
4.0 - |
1.2 + |
2.7 - |
Powder |
1 |
53.0 + |
4.0 + |
15.0 - |
4.0 - |
1.0 + |
2.7 - |
2 |
48.0 + |
5.0 + |
15.0 - |
4.0 - |
1.0 + |
2.7 - |
3 |
46.0 + |
4.0 + |
15.0 - |
4.0 - |
1.5 + |
2.7 - |
4 |
42.0 + |
3.0 + |
17.0 - |
4.0 - |
1.0 + |
2.7 - |
Rockfish |
EP |
1~4 |
46.0 + |
7.0 + |
15.0 - |
4.5 - |
1.2 + |
2.7 - |
5~12 |
43.0 + |
7.0 + |
17.0 - |
3.5 - |
1.5 + |
2.7 - |
Powder |
1 |
35.0 + |
2.0 + |
15.0 - |
4.0 - |
1.5 + |
2.7 - |
Carp |
EP |
1~4 |
40.0 + |
4.0 + |
15.0 - |
4.5 - |
1.2 + |
1.8 - |
5~10 |
35.0 + |
6.0 + |
15.0 - |
4.5 - |
1.0 + |
1.8 - |
Shrimp |
EP |
1 |
50.0 + |
5.0 + |
17.0 - |
5.0 - |
1.2 + |
2.7 - |
2~3 |
45.0 + |
5.0 + |
17.0 - |
5.0 - |
1.2 + |
2.7 - |
4~5 |
40.0 + |
4.0 + |
17.0 - |
5.0 - |
1.2 + |
2.7 - |
6~7 |
38.0 + |
4.0 + |
17.0 - |
5.0 - |
1.2 + |
2.7 - |
* Sources : Cheil Feeds
♦ Nutrition of Rockfish (Sebastes schlegeli)
Korean rockfish EP(sinking) Rockfish is a commercially important fish species in Korea. In culturing this species, fish farmers have used raw fish or moist pellet (mixture of raw fish and binder meal). However, a stable supply of fresh raw fish has become increasingly difficult. Therefore, for further expansion of rockfish farming, it is essential to employ formulated artificial dry feeds which could support reasonable growth.
Research on the nutrient requirements of rockfish have been conducted by the National Fisheries Research and Development Institute (NFRDI) in cooperation with a university and a commercial feed company. The results are summarized as follows. Protein requirements for juvenile and grower fish are around 40%, and dietary lipid requirements ranged 7~10%. Optimum digestible energy to protein (DE/P) ratio estimated to be about 8 kcal/g protein. The upper limits of the carbohydrate and the fiber content are 25% and 10%, respectively. Juvenile rockfish require 0.9% n-3 HUFA (highly unsaturated fatty acids) in diets. The requirements of EPA and DHA are both 1%, and DHA is superior to EPA as an essential fatty acid. The long-term study of vitamin C requirement is approximately 65 mg ascorbic acid (AA)/kg diet in juvenile rockfish. The dietary vitamin E requirement is 45 mg α-tocopheryl acetate (TA)/kg diet for optimum growth in juvenile rockfish.
Based on the nutritional information obtained, a project to develop practical feeds for rockfish has been established. The activities in the project include evaluating protein sources, determining ingredient digestibility, formulating and manufacturing practical feeds, defining feeding programs, and analyzing profitability.
Korean rockfish EP(sinking)
♦ Nutrition of flounder (Paralichthys olivaceus)
Flounder is one of the most important aquaculture species and a popular food fish cultured in Korea. The aquaculture of olive flounder expanded extensively since 1990, the flounder production in Korea ranked the first around world. Nevertheless, the raw fish based moist pellet (MP) diets are still used in most of the intensive inland tank culture system in Korea. The MP diets can cause many problems in flounder culture including disease outbreak, water pollution and high production cost. For the future development of flounder aquaculture in Korea, formulated commercial extruded pellet diets are needed.
This species is a highly carnivorous fish requiring a high dietary intake of protein for growth, however, this species has limited ability to use dietary lipid and then only requires low lipid level in its diet. Formulated flounder feed may include: fishmeal, wheat flour, fish oil, vitamin premix, mineral premix and pellet binder. The establishment of accurate dietary nutrient requirements and the determination of whether less expensive feedstuffs can serve as effective substitutes for fishmeal as a protein source are also conducted in NFRDI etc. Protein requirements for juvenile and grower fish ranged from 44%~46%, and dietary lipid requirements ranged from 7~13%. Optimum digestible energy to protein (DE/P) ratio estimated to be about 8.7 kcal/g protein. The requirements of vitamin C is approximately 93 mg ascorbic acid (AA)/kg diet in juvenile flounder. The dietary vitamin E requirement is 22 mg α-tocopheryl acetate (TA)/kg diet for optimum growth with 7% dietary lipid in juvenile flounder. However, the dietary EPA & DHA requirements and other nutritional requirements have not been measured in flounder, further study should be conducted to provide necessary information to formulate commercial extruded pellet diet for this species.
Olive flounder EP (floating)
 
Pilot scale system in ARC Aqua-farming system in ARC
Developmental cooperation of flounder & rockfish EP diets
Analysis of feed quality
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KOREA-US AQUACULTURE -> Feeds & Nutrition-> Nutrition
