JP2006109709A - Fish feed and method for breeding fish - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide fish feed comprising a composition improving infection protective effect on fish. <P>SOLUTION: The fish feed comprises feed components and water soluble solvent extraction from humus. A method for breeding fish comprises giving the feed to fish. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fish feed containing a feed component and an aqueous solvent extract extracted from humus soil, and a method for raising fish including feeding it to fish.

It is known that soil called humus soil is obtained from wetlands and the seabed, and has been humused to a state where flora and fauna of plankton are deposited and its structural shape is not seen. Humus is rich in fulvic acid, humic acid and various minerals. Moreover, it is known that the extract extracted from humus soil has a bactericidal action, and it was conventionally used as a bactericidal deodorant etc.
JP 7-492 A Japanese Patent Laid-Open No. 10-59861 JP-A-11-29423 JP-A-5-192666 JP-A-6-87752 JP-A 63-84618

  When the present inventors administer fish feed mixed with feed ingredients and extracts extracted from humus using an aqueous solvent to fish, the fish shows a high survival rate even after attack by pathogenic bacteria, and has an effect of enhancing infection protection. As a result, the present invention was completed.

The present invention is a fish feed comprising a feed component and an aqueous solvent extract of humus.
The present invention is also a fish breeding method including feeding the fish feed with the fish feed described above.

  By providing the fish feed of the present invention to the fish, it is possible to enhance the infection protection effect against the pathogenic fungi of the fish, and thus, for example, it is possible to prevent the massive death of the fish due to the infection of the pathogenic fungi in the farm.

In the present invention, the aqueous solvent extract of humus soil is obtained by extracting the humus soil with an aqueous solvent.
The humus soil is mainly composed of humic substances produced by depositing dead bodies of animal and phytoplankton and being decomposed by microorganisms. This humic substance is formed by repeated decomposition and metabolism by microorganisms, and is known to contain various organic substances and minerals.
Although the humus used in this invention is not specifically limited, The soil which exists 5-30 m from the soil surface of a wetland, the soil which exists 0.5-250 m from the seabed surface, etc. can be used preferably.

  As the aqueous solvent, water; acidic aqueous solution such as dilute hydrochloric acid; aqueous alcohol such as aqueous ethanol can be used. Water from which chlorine is removed is preferable. The method for removing chlorine is not particularly limited, and examples thereof include a method of leaving at room temperature for several days, a method using a reducing agent such as ascorbic acid, and a method using an adsorbent such as activated carbon. The pH of the aqueous solvent is not particularly limited, but is preferably in the range of pH 6.0 to 8.0, more preferably in the range of pH 6.3 to 7.5.

A method for obtaining an aqueous solvent extract of humus is not particularly limited, but a method including the following steps (1) to (3) is preferable.
(1) Repeat stirring and standing of the mixture of humus soil and aqueous solvent until the pH is 2.8 or less and the electric conductivity is 400 mV or more,
(2) Remove solids,
(3) Leave the obtained supernatant at ambient temperature for a long time.

In the above step (1), first, in a container such as a water tank, 5 to 10 times (weight ratio) of an aqueous solvent is added to the humus soil while stirring to obtain a suspension.
The resulting suspension is then treated at ambient temperature. In the present specification, the ambient temperature is a temperature of 20 to 45 ° C, preferably 25 to 40 ° C, more preferably 28 to 35 ° C.
The above treatment is preferably performed by repeating stirring and standing. Stirring may be performed to such an extent that the humus deposited at the bottom of the container is diffused into the aqueous solvent, and may be either continuous or intermittent. This treatment is preferably performed until the supernatant obtained by allowing the suspension to stand still has a pH of 2.8 or less, an electric conductivity of about 400 mV or more, and a temperature of 28 ° C. or more for 1 week or more. Such a state can usually be obtained in about 3 to 5 weeks after mixing the humus and the aqueous solvent. In this step, nutrient sources such as a nitrogen source and a phosphorus source can be added as desired.

  The method for removing the solid matter in the step (2) is not particularly limited as long as it can separate the humus soil and the liquid and remove the humus soil, but may be performed by standing, centrifugation, or the like. it can. In the method of standing, the suspension is allowed to stand at 25 to 35 ° C. for about 150 to 240 hours to precipitate humus soil, and then only the supernatant is obtained. In order to remove the solid matter more reliably, the suspended matter may be further removed using a cloth or the like. The supernatant thus obtained has a pH of about 2.5 to 3.0.

  Step (3) is performed by allowing the obtained supernatant to stand at ambient temperature for a long period of time. The long term may be about 180 to 500 days, preferably about 300 to 400 days. During this standing, the temperature may be constant or may vary. Usually, when it hold | maintains for 30 to 60 days at the temperature of 25-35 degreeC, and hold | maintains for 30 to 60 days at the temperature of 5-15 degreeC, the aqueous-solvent extract of a more preferable humus soil can be obtained.

  The liquid obtained by the above standing may be further filtered. Filtration may be performed as long as suspended matter in the liquid can be removed. For example, the filtration can be performed using two types of membrane filters having a pore diameter of 40 to 100 μm and 10 to 40 μm.

The aqueous solvent extract of humus soil obtained by the above method is a light brown, substantially odorless liquid having a pH of 2.0 to 3.0 and an electrical conductivity of 350 to 500 mV.
In addition, the aqueous solvent extract of humus has a weight after freeze-drying of 0.5 to 1 g per 100 ml of the aqueous solvent extract of humus, and is adsorbed through the DAX-8 resin column (fulvic acid). The weight after freeze-drying is 0.001 g or less per 100 ml of the aqueous solvent extract of humus.

The aqueous solvent extract of the above humus soil preferably contains the following components in 1 liter.
Calcium 200-300 ppm
Sulfur 1000-1500 ppm
Iron 10-50 ppm
Zinc 1-8 ppm
Copper 0.1-1 ppm
Sodium 80-100 ppm
Manganese 5-10 ppm
Magnesium 80-100 ppm
Aluminum 300-400 ppm
Silicon 30-40 ppm
Nickel 0.1-1 ppm
Strontium 0.5-5 ppm
Yttrium 0.1-1 ppm
Lithium 0.1-1 ppm

Furthermore, the aqueous solvent extract of the above humus can contain a trace amount of boron, lanthanum, scandium, selenium and the like.
Each of these components can be measured using a high frequency induction analyzer (ICP).

  The extract of humus can be solidified by adding an appropriate carrier. The carrier is not particularly limited as long as it is a component that can be used as fish feed, and examples thereof include starch and saccharides.

The fish feed of the present invention can be produced by adding and mixing the aqueous solvent extract of the above humus soil to the feed components.
The feed ingredient is not particularly limited as long as it is an ingredient used as a normal fish feed, and feed ingredients (e.g. fish meal, starch, breeding yeast, wheat gluten, vegetable gum, skim milk, cottonseed meal, rice bran, vitamins, etc. Organic nutrient sources; inorganic nutrient sources such as salt, calcium phosphate and calcium carbonate), normal fish feeds containing one or more of these, and mixtures thereof.

  As a method of adding and mixing the feed component and the aqueous solvent extract of humus soil, after mixing the feed raw material and the aqueous solvent extract of humus soil in advance, it is made into a desired dosage form such as powder, granule, pellet form, etc. Examples thereof include a method of forming, a method of mixing a normal fish feed and an aqueous solvent extract of humus soil, and further forming if desired. More specifically, for example, a composition for adding fish feed is mixed with one or more of the above feed raw materials in a powdered state before molding using a commonly used mixer, and then as necessary. A method for producing fish feed by molding with an extruder, pelleter or the like can be mentioned.

  The fish feed of the present invention preferably contains an aqueous solvent extract of humus soil in the range of 1 to 20% by weight, more preferably 5 to 10% by weight, based on the feed components. If the amount is not more than the above range, the effect of enhancing infection defense by providing the fish feed is not sufficient. Moreover, since it cannot expect the improvement of the effect corresponding to an excess part as it is more than said range, it is uneconomical.

  For fish feed, conventional additives used for fish feed, such as preservatives (for example, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, sorbic acid) and coloring agents, as long as the effect of enhancing the defense against infection is not impaired. Can be added.

  The amount of fish feed of the present invention is appropriately increased or decreased depending on the type of fish, individual body weight, etc., but if it is given about 5 to 10 g per day per 100 g of fish body weight, a sufficient effect of enhancing infection protection can be obtained. it can.

  By giving the fish feed of the present invention to fish, the effect of enhancing the defense against infection of fish can be obtained. Thus, the fish breeding method including providing the fish feed of the present invention to the fish is one of the embodiments of the present invention.

  The fish to be bred in the fish breeding method of the present invention is not particularly limited, and any of freshwater fish such as trout, carp, sweetfish, eel, goldfish, and seawater fish such as Thailand, yellowtail, flounder, and pufferfish that are generally cultivated. There may be.

  By giving the fish feed of the present invention, nocardiosis, streptococcal disease, vibriosis, eromonas disease, perforated disease, paracortic disease, cold water disease, gliding bacteriomyopathy, nodular disease, edovadierosis, bacterial kidney disease, Increases defense against bacterial diseases such as bacterial gonorrhea, mania, fungus diseases such as cotton blast disease, ichthyophonus disease, Blanciomyces disease, and viral diseases such as iridovirus, birnavirus, rhabdovirus and herpes virus be able to.

Example 1
Using the aqueous solvent extract of humus used in the present invention, the effect of protecting against carp puncture disease (a kind of Aeromonas disease) was examined.
Manufacturing method of aqueous solvent extract of humus soil Add pH 6.5 dechlorinated water with stirring to the humus soil sampled at a point 20 m from the soil surface in Nagasaki Prefecture. The mixture was left with stirring twice. Thereafter, the suspension was allowed to stand to obtain a supernatant, which was filtered with a cloth to remove the suspended matter, and allowed to stand at ambient temperature for 365 days. During this period, the maximum ambient temperature was 30 ° C., and the minimum temperature was 10 ° C. The obtained supernatant was filtered with a housing filter (manufactured by Cuno) having a pore size of 50 μm and 25 μm to obtain an aqueous solvent extract of humus soil. The pH of the aqueous solvent extract of the obtained humus soil is 2.8 ± 0.05 (measured with a pH meter Model 9620 manufactured by Horiba, Ltd.), and the electrical conductivity is 400 mV or more (electric conductivity meter manufactured by Horiba, Ltd.). 9382-10D type). In addition, the lyophilized weight per 100 ml of the aqueous solvent extract of the obtained humus soil was 0.65 g, and the weight after lyophilization of the components adsorbed on the DAX-8 resin column (manufactured by Spelco) was 0.0002 g. there were.
Table 1 shows the results of measuring the aqueous solvent extract of the humus soil with a high-frequency induction analyzer (ICP, manufactured by PerkinElmer).

Test method of infection prevention effect against puncture disease Carp feed for humus soil so that it becomes 5% and 10% (w / w) And mixed to produce a fish feed.
In addition, dechlorinated tap water was added to the carp feed as a control feed. These fish feeds were given to carps twice a day for 4 weeks. Next, these carp were attacked by immersion in water containing 5.9 × 10 ⁵ bacteria / ml of Aeromonas salmonicida, a pathogen of carp puncture disease. Ten carp were used per group, the average body weight at the start of the experiment was 26 g, and the daily feed dose was 1.5 g. The breeding water temperature was 13 ° C. at the start of the experiment and 18 ° C. at the start of the immersion attack.

After the immersion attack, the carp was observed for 15 days for life and death and with the naked eye, and the dead carp was separated from the lesion and internal organs. At the end of the experiment, fungi were also isolated from the surviving fish. The survival rate was calculated from the life and death of carp, and the lesions on the body surface were scored using the following criteria to calculate the average value.
5 Mortality 3 Severe, perforated 2 Medium 1 Minor 0 No lesion In addition, continue to control during the observation period and fish feed containing 5% and 10% (w / w) humus soil extract dilution, respectively. Administered.

Results FIG. 1 shows the survival rate of carp after immersion challenge with Aeromonas salmonicida, and FIG. 2 shows the average value of lesion evaluation observed with the naked eye. As is apparent from this figure, the carp fed with the control diet began to die on the 7th day after the attack, and the survival rate after 15 days was 20%. On the 10th day after the attack, the skin lesions were in the so-called “perforated” state, and the muscles were exposed due to severe ulcers. Aeromonas salmonicida was isolated from bleeding lesions and ulcers on the body surface.

Carp that received an aqueous solvent extract of 5% humus soil had no or no skin lesions observed and no fish died. Also, no bacteria were isolated from fish skin and abdominal organs.
Carp fed with 10% humus soil aqueous solvent extract had minor skin lesions and only one died after 11 days. No fungi were isolated from the skin and intra-abdominal organs of the surviving fish.

From these results, it can be seen that by providing the fish with the fish feed of the present invention, it is possible to enhance the effect of preventing infection against carp hole disease.
Although the mechanism of action of the aqueous solvent extract of humus soil used in this application is not clear, the aqueous solvent extract of humus soil is absorbed from the intestinal tract or is present in the blood Therefore, it is considered that physiological changes occur in the body of fish, resulting in a protective effect against infection.

FIG. 1 is a graph showing the survival rate of carp after immersion attack with Aeromonas salmonicida. FIG. 2 is a graph showing the average value of the evaluation of lesions observed with the naked eye after immersion attack with Aeromonas salmonicida.

Claims (5)

  A fish feed comprising an aqueous solvent extract of humus soil.   The aqueous solvent extract of humus soil has a pH of 2.0 to 3.0, contains calcium, iron, sodium, magnesium, aluminum and silicon as minerals, and contains 1000 to 1200 ppm of sulfur. The fish feed according to 1. An aqueous solvent extract of humus soil
(1) Repeat stirring and standing of the mixture of humus soil and aqueous solvent until the pH is 2.8 or less and the electric conductivity is 400 mV or more,
(2) Remove solids,
(3) The fish feed according to claim 1 or 2, which is obtained by a step of allowing the obtained supernatant to stand at ambient temperature for a long period of time.   Fish feed containing an aqueous solvent extract of 1-20% by weight of humus soil with respect to the feed ingredients.   A method for raising fish, comprising feeding the fish feed according to any one of claims 1 to 4 to the fish.

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