JP2005027613A - Mixed feed for cultured fish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have an optimal nutritional balance, optimal size and softness for cultured fish, especially large-scale cultured fish such as tuna, and to maintain its shape and to actively eat at all water temperatures where the cultured fish can grow To provide a mixed feed for cultured fish that grows well with food and can be stored at room temperature.
SOLUTION: A blended feed having a crude fat content of 8 to 70% by mass, a water content of 5 to 50% by mass and a water activity of 0.900 or less is prepared using an edible film having a thickness of 10 to 100 μm. It is sealed in a size of 10 to 300 mm and a diameter of 5 to 100 mm, and the inclusion has a softness with a breaking strength of 60 g / mm or less.
[Selection figure] None

Description

  The present invention relates to sea-cultured fish such as tuna (bluefin tuna, southern bluefin tuna, etc.), yellowtail, amberjack, hiramasa, striped mackerel, grouper (mahata kue, etc.), Japanese flounder, trough pufferfish, red sea bream, salmon, trout, etc. The present invention relates to a mixed feed for cultured fish that is suitable for large-scale cultured fish such as hamachi and hiramasa.

  The fish selectively feeds a bait having an appropriate size and an appropriate softness according to the growth. Moreover, the selection range of the softness of the food becomes narrow according to the water temperature fluctuation. Furthermore, the balance between nutritional requirements and ingredients varies depending on the seasonal variation and fish size, and growth and weight will worsen unless the proper amount of food is consumed. In fish farming, how to feed with the right size, softness and proper nutrition balance according to the growth and season of the fish is an important factor in productivity.

  Commonly known as “raw food”, which is used for freshly caught fish or frozen sardines, sardines, sardines, etc. Since it is a bait itself, it shows active feeding, but water pollution due to the elution of nutrients in the water, and the incidence of disease increases accordingly. In addition, there are restrictions on the types of fish that can be obtained because of natural products, and there are variations in quality, so the size and nutritional balance of the bait cannot be adjusted. Furthermore, since refrigeration is required for storage, there is a drawback that a large amount of capital investment is required for storage facilities.

  In order to control water pollution and adjust the nutritional balance, the main ingredients are “raw food” and fish meal, wheat flour, soybean meal, rice bran, and various vitamins and minerals, as well as sodium alginate, sodium carboxymethylcellulose ( CMC), mixed feed made into a powder form by binding a binder such as gua gum, and oil such as fish oil and soybean oil or a solid feed containing high fats and fats, and so-called “moist pellets” Although it has a feeding ability comparable to that of “raw food”, it does not cover variations in quality due to the use of “raw food”, requires a large amount of capital investment in storage facilities and manufacturing facilities, and increases feeding operations. . In addition, the strength of the pellet is low, and a large moist pellet cannot be produced.

  Solid fish feed that uses only mixed feed and is molded with a steam pelleter or extruder can be adjusted to a wider range of nutritional components than raw feed or moist pellets, and is heated during the manufacturing process. Therefore, since it can be stored at room temperature, it is a type of feed for cultured fish that has become popular in recent years. However, in the current production method, the upper limit is a size of about 40 mm in diameter and 60 mm in length, and the limit of the crude fat content is about 40% by mass. In addition, in the low water temperature period, the feeding ability is slightly lower than that of “live food” and “moist pellet”.

  As feed for cultured fish that can be increased in size, add salt or phosphate to raw fish minced or moist pellets, stir, then heat at room temperature or product temperature 70 ° C or lower to form a gel and pelletize Kamaboko type mixed feed for cultured fish is known. Although this kamaboko type mixed feed for cultured fish retains the strength of the pellets even in a large size, there is a limit to the adjustment of nutritional components, especially the maximum crude fat content of about 30% by mass. Is not suitable.

  In addition, intestinal stuffed mixed feed for cultured fish in which feed is enclosed with an edible film is known. For example, Patent Literature 1 proposes a mixed feed for cultured fish in which a carrageenan casing is filled with moist pellets. However, this mixed feed for cultured fish has not been studied for the physical properties of the fish and the ingredients to grow, and because moist pellets are used, there are problems such as variations in quality and storage at room temperature. There is.

Therefore, aquaculture fish producers change the type of food to be fed according to the growth of the aquaculture fish, seasonal fluctuations and water temperature fluctuations, but for large aquaculture fish such as tuna, the proper nutritional balance and the appropriate size and softness The present condition is that the body weight cannot be fed, the obesity level decreases as it grows, and the growth efficiency deteriorates.
There is a demand for a simple mixed feed for cultured fish that realizes softness and size with good feeding property, has high growth efficiency, and can be stored at room temperature.

JP-A-4-40861

  The object of the present invention is to have an optimal nutritional balance, optimal size and softness for cultured fish, especially large-scale cultured fish such as tuna, etc., and maintain its form at all water temperatures at which the cultured fish can grow. The object is to provide a mixed feed for cultured fish that can be stored at room temperature, with active feeding and excellent growth.

  The present invention is a length in which a blended feed having a crude fat content of 8 to 70% by mass and a water content of 5 to 50% by mass and a water activity of 0.900 or less is enclosed with an edible film having a thickness of 10 to 100 μm. The object is achieved by providing a mixed feed for cultured fish having a size of 10 to 300 mm and a diameter of 5 to 100 mm and a softness of breaking strength of 60 g / mm or less.

  According to the present invention, it has an optimal nutritional balance and optimal size and softness for cultured fish, especially large-scale cultured fish such as tuna, and maintains its form, at all water temperatures at which the cultured fish can grow. It is possible to provide a mixed feed for cultured fish that can be stored at room temperature, which is actively fed and has excellent growth.

Hereinafter, preferred embodiments of the mixed feed for cultured fish of the present invention will be described in detail.
In the present invention, the thickness of the edible film is set to 10 to 100 μm because the strength as a packaging material cannot be maintained if it is less than 10 μm, and the strength is too strong if it exceeds 100 μm and the feed cannot be adjusted to the softness preferred by fish. It is. The thickness of the edible film is preferably about 10 to 60 μm, more preferably 20 to 40 μm, from the viewpoints of physical properties, economy and handling.

  The edible film forming materials include collagen, agar, pullulan, starch, mannan, soybean protein, enzyme-degraded soybean protein, gelatin, carrageenan, alginic acid and its salts, gum arabic, chitosan, dextrin, edible water-soluble A simple substance such as cellulose or a mixture of two or more thereof may be mentioned. All of these edible film-forming materials are derived from natural products and do not adversely affect farmed fish when fed. Moreover, it has sufficient strength as a casing material and is easy to handle. Furthermore, it is not destroyed by the encapsulated mixed feed.

  As a raw material of the compounded feed enclosed in the said edible film, the raw material of the conventional compounded feed for cultured fish can be used. For example, raw fish, fish meal, soybean oil cake, protein such as corn gluten meal, starch such as starch, wheat flour, gluten, binder such as sodium alginate, sodium carboxymethylcellulose (CMC), guagum, vitamins, minerals, etc. It is.

  The above-mentioned mixed feed has a raw fat content of 8 to 70% by mass, particularly when feeding large cultured fish, the crude fat content is preferably 15% by mass or more, more preferably 20% by mass or more, and most preferably Is blended so as to be 25% by mass or more. A large amount of crude fat content has an excellent effect on the growth and growth efficiency of cultured fish. However, if the crude fat content exceeds 70% by mass, other components are inevitably reduced, making it difficult to adjust the nutritional balance. Become. The crude fat referred to here includes animal fats and oils such as fish oil and vegetable fats and oils such as soybean oil, in addition to fats derived from raw materials.

  The mixed feed is adjusted so that the water activity is 0.900 or less, preferably 0.800 or less, more preferably 0.600 or less. This water activity is an important numerical value for suppressing the growth of microorganisms and storing feed at room temperature. The adjustment of the water activity can be adjusted by the composition of the mixed feed. For example, the water activity of the formulated feed can be lowered by adjusting the amount of water added. Salts (salt, sodium malate, sodium lactate, etc.), sugars (sugar, lactose, maltose, sorbit, etc.), amino acids, nucleic acid-related substances, organic acids, alcohols, propylene glycolose, glycerin, starches, proteins, etc. The water activity of the formulated feed may be adjusted by adding the water activity regulator.

  Thus, by setting the water activity of the blended feed to 0.900 or less, the moisture content of the blended feed can be widely adjusted to 5 to 50% by mass. The water content of the blended feed is preferably 5 to 40% by weight, more preferably 5 to 20% by weight from the viewpoints of adjustment of water activity and the softness and nutritional balance of the resulting blended cultured fish feed. Good.

Thus, the mixed feed for cultured fish of the present invention is obtained by encapsulating the mixed feed with the edible film, and can be manufactured to have a length of 60 mm or more and a diameter of 40 mm or more.
The size of the mixed feed for cultured fish according to the present invention is 10 to 300 mm in length and 5 to 100 mm in diameter. For cultured fish suitable for baits having a length of less than 10 mm or less than 5 mm in diameter, This is because sufficient feed and growth can be achieved even with a solid feed, and when the length exceeds 300 mm or the diameter exceeds 100 mm, the size of the feed is too large for the cultured fish. For example, in the case of large-scale aquaculture fish such as tuna, amberjack, yellowtail and hiramasa, the size is preferably 60 to 300 mm in length and 40 to 100 mm in diameter, more preferably 60 to 200 mm in length and 40 to 70 mm in diameter. .

  Moreover, the mixed feed for cultured fish of the present invention has a softness of breaking strength of 60 g / mm or less. The breaking strength is a numerical value obtained by “breaking stress / dent”. Here, the breaking stress and the dent were measured by using a Sun Leo-Tex SD700 (manufactured by San Kagaku Co., Ltd.) as a measuring device, using a spherical plunger with a diameter of 5 mm at a plunger speed of 60 mm / min and a plunger load of 35 g. It has been done. The measuring method is that the plunger is pressed perpendicularly to the measured object, and the force required for the measured object to lose resistance and break (= breaking stress (g)) and the distance at that time (= dent (mm) ]. Since the breaking stress and the dent have a positive proportional relationship, the breaking stress was divided by the dent, and the coefficient was taken as the breaking strength (g / mm).

  If the breaking strength of the cultured fish blended feed exceeds 60 g / mm, the feed becomes hard and does not show satisfactory feeding. In particular, fish that have just been collected from nature or fish at low water temperatures may not feed at all, or may spit after feeding. The softness is preferably a breaking strength of 40 g / mm or less, more preferably a breaking strength of 30 g / mm or less, and most preferably a breaking strength of 20 g / mm or less.

  The breaking strength of the mixed feed for cultured fish of the present invention can be adjusted by the composition and production conditions of the mixed feed to be enclosed in the edible film. For example, blending a large amount of liquid raw materials such as oil and moisture can soften a mixed feed for cultured fish, and conversely, stiffening a mixed feed for cultured fish by blending a large amount of powdered raw materials such as fish meal. be able to. Moreover, the breaking strength of the cultured fish mixed feed can also be adjusted by the amount of the mixed feed enclosed in the edible film.

  The method of encapsulating the blended feed in the edible film is not limited, for example, a method of filling the blended feed into a cylindrical edible film and sealing both ends, and two edible properties This is done by placing a mixed feed between the films and sealing all sides.

Since the mixed feed for cultured fish according to the present invention does not require heating, it is possible to effectively use heat-sensitive enzymes and vitamins. Furthermore, since there is no elution into the environmental water, it is possible to incorporate the nutrients and chemicals into the fish without waste.
The mixed feed for cultured fish of the present invention is suitable for large-scale cultured fish, particularly tuna, amberjack, hamachi, hiramasa and the like.

  Hereinafter, although an example and a comparative example are given and the present invention is explained still more concretely, the present invention is not restricted at all by the following examples.

[Example 1]
Prepare a blended feed by thoroughly mixing 40.0 parts of fish meal (mass basis, the same shall apply hereinafter), 19.0 parts of soybean meal, 1.0 part of vitamins and minerals, 5.0 parts of water and 35.0 parts of fish oil. did. This mixed feed had a crude fat content of 38% by mass, a water content of 10% by mass, and a water activity of 0.800.
A cylindrical collagen casing having a diameter of 27 mm and a thickness of 30 μm is filled with the above-mentioned mixed feed for a length of 150 mm (the amount of mixed feed is 75 g), and both ends are sealed with a heat sealer to obtain the mixed feed for cultured fish of the present invention It was.
This cultured fish blended feed had a softness of breaking strength of 15 g / mm.

[Example 2]
About the following samples 1-5, it fed to 1500 bluefin tuna fish of about 30 kg of average fish weight each accommodated in 50mx50mx15m sea surface sacrifice, and the feeding state was observed. Bluefin tuna were fed “live food” (such as squid and mackerel) until the test.
Sample 1: Formulated feed for cultured fish of the present invention obtained in Example 1 Sample 2: Example 1 except that the amount of formulated feed in the collagen casing was 110 g
The aquaculture of the present invention having a softness of breaking strength of 33 g / mm produced in the same manner
Formula feed for fish Sample 3: Example 1 except that the amount of formula feed in the collagen casing was 165 g
The culture of the present invention having a softness of 57 g / mm breaking strength produced in the same manner
Formula feed for fish Sample 4: 75 parts of frozen fish mince, formula feed (trade name “Firebo
”) 24 parts, 1 part of vitamins and minerals is gel-formed at a product temperature of 40 ° C.,
70g breaking strength pelletized to 30mm diameter and 120mm length
/ Mm mixed feed for cultured fish Sample 5: Manufactured in the same manner as Sample 4 except that the gel formation temperature was 55 ° C.
Formulated feed for cultured fish with a degree of 152 g / mm The observation results were as follows.
Sample 1 ate and swallowed as soon as it was fed. No behavior to vomit was observed. Samples 2 and 3 were bitten and swallowed as well as Sample 1. Although there were few individuals who swallowed immediately in sample 4, but in sample 5 most fish were not swallowed, and in both samples 4 and 5, many swallowed individuals exhaled several meters away From this, it can be seen that the limit of breaking strength of the mixed feed for cultured fish of the present invention is 60 g / mm.

Example 3
A mixed feed was prepared by thoroughly mixing 40.0 parts of fish meal, 3.0 parts of wheat gluten, 16.0 parts of fish oil, 1.5 parts of vitamins and minerals, and 39.5 parts of water with a mixer. This blended feed had a crude fat content of 20% by mass, a crude protein content of 29% by mass, a water content of 43% by mass, and a water activity of 0.860.
A cylindrical collagen casing having a diameter of 15 mm and a thickness of 30 μm is filled with the above mixed feed (mixed feed amount 6 g), both ends are sealed with a heat sealer, and the mixed feed for cultured fish of the present invention (diameter 15 mm × length 25 mm) Got.
This mixed feed for cultured fish had a softness with a breaking strength of 19 g / mm.
Amberjacks were bred for 24 days using this mixed feed for cultured fish (water temperature 22 ° C.). On the other hand, for comparison, the same breeding was performed using a commercially available EP feed (produced by Hayashi Kane Sangyo Co., Ltd., crude fat content 20 mass%, crude protein content 43 mass%, water content 8 mass%). The results are shown in Table 1 below.

  As is clear from the results shown in Table 1, the mixed feed for cultured fish of the present invention produces results superior to conventional fish feed. Moreover, when the mixed feed for cultured fish of the present invention obtained in the present example was fed to flounder and reared, excellent breeding results similar to those of the above-described amberjack breeding were obtained.

Example 4
A mixed feed was prepared by thoroughly mixing 50.5 parts of fish meal, 20.0 parts of soybean oil residue, 20.0 parts of fish oil, 1.5 parts of vitamins and minerals, and 8.0 parts of water with a mixer. This blended feed had a crude fat content of 24% by mass, a crude protein content of 43% by mass, a water content of 11% by mass, and a water activity of 0.800.
A cylindrical collagen casing having a diameter of 13 mm and a thickness of 30 μm is filled with the above mixed feed (the amount of the mixed feed is 3.5 g), both ends are sealed with a heat sealer, and the mixed feed for cultured fish of the present invention (diameter 13 mm × length) 15 mm).
This cultured fish blended feed had a softness of breaking strength of 17 g / mm.
Amberjacks were bred for 32 days using this mixed feed for cultured fish. The water temperature was 18 ° C., which is a low water temperature in amberjack. On the other hand, the same breeding was carried out using a commercially available EP feed (manufactured by Hayashi and Sangyo Co., Ltd., crude fat content 24 mass%, crude protein content 43 mass%, water content 8 mass%) for comparison. The results are shown in Table 2 below.

  As is clear from the results shown in Table 2 above, the mixed feed for cultured fish of the present invention produces results superior to conventional fish feed even under low water temperature conditions.

[Embodiment 5]
The mixed feed for cultured fish of the present invention obtained in Example 1 was fed to bluefin tuna with an average fish weight of about 50 kg for 30 days. On the other hand, for the purpose of comparison, the same breeding was carried out using raw foods such as squid and mackerel (crude fat content 7-16% by mass, crude protein content 18-21% by mass, water content 61-78% by mass). When the degree of obesity at the end of 30 days of breeding was measured, the degree of obesity when feeding the cultured fish mixed feed of the present invention was 22.8 to 24.1, and the degree of obesity when feeding raw food Was 21.3 to 23.4. The degree of obesity is a numerical value indicating the fatness of the fish, and the higher the numerical value, the greater the fatness. As is clear from this result, the mixed feed for cultured fish of the present invention can feed a bluefin tuna with an appropriate nutritional balance, and a result superior to conventional live food-based aquaculture can be obtained.

Example 6
A blended feed (No. 1 to 3) was prepared in the same manner as in Example 1 except that the raw material blend shown in Table 3 below was used. The crude fat content, crude protein content, water content and water activity of these mixed feeds are shown in Table 3 below.
Using these mixed feeds, the mixed feed for cultured fish of the present invention was obtained in the same manner as in Example 1. Table 3 also shows the breaking strengths of these mixed feeds for cultured fish. As is clear from this result, the mixed activity for cultured fish of the present invention can adjust water activity.
Moreover, when the obtained mixed feed for cultured fish of the present invention was fed to tuna, active feeding was observed in all feeds.

Claims (7)

  10 to 300 mm in length, in which a blended feed having a crude fat content of 8 to 70% by mass and a water content of 5 to 50% by mass and a water activity of 0.900 or less was enclosed with an edible film having a thickness of 10 to 100 μm, A formulated feed for cultured fish having a diameter of 5 to 100 mm and a softness of breaking strength of 60 g / mm or less.   The formulated feed for cultured fish according to claim 1, having a softness of breaking strength of 40 g / mm or less.   The mixed feed for cultured fish according to claim 1 or 2, having a length of 60 to 300 mm and a diameter of 40 to 100 mm.   The mixed feed for cultured fish according to any one of claims 1 to 3, wherein the cultured fish are tuna, amberjack, yellowtail, and flounder.   The mixed feed for cultured fish according to any one of claims 1 to 4, wherein the mixed feed has a crude fat content of 15 to 70% by mass.   The mixed feed for cultured fish according to any one of claims 1 to 5, wherein the water activity of the mixed feed is 0.800 or less. The mixed feed for cultured fish according to any one of claims 1 to 6, wherein the water activity of the mixed feed is adjusted by adding a water activity adjusting agent.