JP4863615B2 - Functional fish feed - Google Patents

Description

  The present invention relates to a functional fish feed suitable for prevention of infection caused by Flavobacterium, particularly a functional fish feed suitable for preventing fin defects.

In recent years, cold water disease of cultured fish has become a serious problem in farms such as rainbow trout ( Oncorhynchus mykiss ), ayu ( Plecoglossus altivelis ), coho salmon ( Oncorhynchus kisutch ) and the like. Cold water disease is said to occur every year in about half of the domestic ayu farms, and when fish that carry cold water germs are released into rivers, infection and onset of cold water disease in natural fish Mass death due to has been reported.

Cold water disease is a bacterial infection caused by Flavobacterium syphilophilum infection that occurs even at low water temperatures of 5-10 ° C.
It is known that fish infected with cold water disease develop symptoms such as anemia of pupae and liver, cloudiness of the body surface, ulcers of the body surface, and defect of fins, and the mortality rate is particularly high in juvenile fish.

In addition, farmed fish are generally kept in a crowded state in a breeding pond partitioned by concrete walls or skeins, etc., and the surface of the body may be damaged due to contact between farmed fish and the wall. There is. It is known that Flambacterium columnar (gram-negative bacilli) is likely to develop columnaris disease from the wound site. It is known that fish infected with columnaris disease develop inflammation and damage at the site of infection, and when the fish progress, the tissue melts and becomes necrotic and moribund.

  Antibiotics and other medicines are used for the prevention and treatment of these diseases, but there are problems that the effect is reduced due to the emergence of resistant bacteria and that antibiotic components remain in the fish body due to overdose. In addition, as a countermeasure using the temperature characteristics of the bacteria, there is a method of raising the breeding water temperature, but there is a problem that the installation of the heating equipment and the cost burden of the fuel cost are large. Furthermore, it has been reported that Pseudomonas disease frequently occurs in fish (particularly, fish from Lake Biwa) that have been raised in temperature by raising the breeding water temperature, and causing great damage due to the spread of infection.

By the way, the commercial value of the cultured fish depends on the appearance of the fish body, especially the state of the fins, and it is important to enhance the commercial value of the cultured fish that the breast fin, dorsal fin and tail fin are free from defects.
Infectious diseases caused by Flavobacterium genus bacteria such as the cold water disease and the columnar disease have not only a harmful effect of causing drowning but also a serious problem of reducing the commercial value of the cultured fish due to the damage of fins. There is an urgent need for preventive measures.
In particular, cultured fish as foodstuffs are strongly required to have no chemical components remaining in the fish body from the viewpoint of food sanitation, and the increase in prevention costs leads to a rise in the price of the cultured fish in the market. Because there are problems, a safe and simple prevention method is required.

  Therefore, there is currently no means to prevent infections caused by Flavobacterium bacterium without causing any harmful substances to remain or accumulate in the fish body. Development is highly desired.

An object of the present invention is to solve the conventional problems and achieve the following objects.
That is, the present invention is a functional fish farm that can be administered as a normal feed, does not contain harmful substances that remain and accumulate in the fish body, prevents infection by Flavobacterium bacteria, and in particular prevents fin damage. The purpose is to provide feed.

Means for solving the problems are as follows. That is,
<1> 0.1% by mass to 0.2% by mass of grape ( Vitis spp. ) Seed extract and 0.1% by mass to 0.2% by mass of β-1,3 / 1,6-glucan A functional fish farm feed characterized in that it is used for prevention and recovery of fin damage caused by Flavobacterium genus bacteria.
< 2 > Grape seed extract is the feed for functional fish farming according to <1>, wherein proanthocyanidins are contained in an amount of 38 % by mass to 60% by mass.
< 3 > The function according to any one of <1> to < 2 >, wherein 0.5 % by mass to 1.0% by mass of vitamin C and 0.1 % by mass to 0.2 % by mass of vitamin E are contained. It is a feed for sex fish.
< 4 > The functional feed for aquaculture according to any one of <1> to < 3 >, which is used for prevention of infections caused by Flavobacterium genus bacteria of salmonid and cyprid fishes.
< 5 > The functional fish farm feed according to any one of <1> to < 4 >, which is used for prevention of infections caused by Flavobacterium genus larvae of rainbow trout ( Oncorhynchus mykiss ).
<6> Flavobacterium columnare, and a functional fish feed according the to be used in the prevention of infection by at least one of Flavobacterium Psychrophillum from <1> to <5>.

  According to the present invention, conventional problems can be solved, it can be administered as a normal feed, does not contain harmful substances that remain or accumulate in the fish body, prevents infection by Flavobacterium, and damages to fins It is possible to provide a functional feed for fish farming that can prevent the above.

(Functional fish feed)
The functional fish farm feed of the present invention contains a grape seed extract and β-1,3 / 1,6-glucan, and optionally contains vitamins and other components, and includes Flavobacterium genus Used to prevent bacterial infections.

<Grape seed extract>
The grape seed extract is not particularly limited as long as it is an extract extracted from grape seeds with water, an organic solvent, or a mixture thereof, and can be appropriately selected according to the purpose. The extract preferably contains proanthocyanidins.
The grape seed varieties are not particularly limited and can be appropriately selected according to the purpose, but varieties having a high proanthocyanidin content are preferable, for example, white feather species, and Miratorgau species, Zweigel species, Saber species, And Campbell species.

The proanthocyanidins are compound groups in which flavan-3-ol and flavan-3,4-diol are combined as constituent units by condensation or polymerization, and procyanidins that produce anthocyanidins such as cyanidin, delphinidin, pelargonidin by acid treatment, Includes prodelphinidin, propelargonidin, and stereoisomers thereof.
As said seed extract, what contains 38-60 mass% of said proanthocyanidins is preferable, and what contains 40-50 mass% is more preferable.

As content of the said grape seed extract, it is preferable that it is 0.1-0.2 mass% with respect to 100 mass% of said functional fish feed, and it is more preferable that it is 0.1 mass%.
If the content of the grape seed extract is less than 0.1% by mass, the effect of preventing infection by Flavobacterium may not be obtained, and if it exceeds 0.2% by mass, fin defects are lost. The rate suppression effect may be limited.

<Β-1,3 / 1,6-glucan>
The β-1,3 / 1,6-glucan includes at least one glucopyranose unit bonded by a β-1,6 glycosidic bond to a main chain composed of glucopyranose units bonded by a β-1,3 glycosidic bond. The glucan having one side chain is not particularly limited and may be appropriately selected according to the purpose. However, a glucan containing 6% or more of the β-1,6 glycosidic bond is preferable.
Examples of the β-1,3 / 1,6-glucan include glucan extracted from the cell wall of microorganisms, and specifically, baker's yeast ( Saccharomyces cerevisiae), black yeast ( Aureobasidium pullulans ), etc. Extracted from the cell wall.

The β-1,3 / 1,6-glucan content is preferably 0.1 to 0.2% by mass with respect to 100% by mass of the functional fish feed, and 0.1% by mass. It is more preferable that
When the content of β-1,3 / 1,6-glucan is less than 0.1% by mass, an effect of preventing infection by Flavobacterium may not be obtained, and the content is 0.2. When the mass% is exceeded, the weight gain (feed efficiency) of the fish body relative to the dose of the feed may decrease. The feed efficiency is determined by the following formula.
Feed efficiency (%) = weight gain (g) × 100 / feed dose (g)

<Vitamins>
Examples of the vitamins include water-soluble vitamins, fat-soluble vitamins, vitamin-like substances, and provitamins. Among these, a combination of vitamin C and vitamin E is preferable.
The content of vitamin C is preferably 0.5 to 1.0% by mass, and the content of vitamin E is preferably 0.1 to 0.2% by mass.

<Other ingredients>
The other components are not particularly limited and can be appropriately selected depending on the purpose.For example, amino acids, minerals, pigments, lactoferrin, natto spores, garlic extract, taurine, glutathione, phytoacetate, lysozyme, Examples thereof include DHA, phospholipid, betaine, and casein phosphopeptide.

<Food feed base>
There is no restriction | limiting in particular as a feed base for fish raising to which said each component is added, According to the kind of fish to administer, a growth stage, etc., it can select suitably. For example, the feed etc. which consist of fish meal, wheat flour, and soybean meal powder as a main component are mentioned.

  The shape of the functional fish feed is not particularly limited, and can be appropriately selected according to the type of fish to be administered, the growth stage, etc., for example, paste, solid (including moist pellets), and Examples include powder.

There is no restriction | limiting in particular as a manufacturing method of the said feed for functional fish farming, According to the objective, it can select suitably. For example, at least the grape seed extract and the β-1,3 / 1,6-glucan may be blended in advance with the feed base for fish farming, and prepared and molded according to a conventional method. At least the grape seed extract and the β-1,3 / 1,6-glucan may be added to the formulated feed prepared and formed as a feed base by a method such as coating.
Also, the grape seed extract, the β-1,3 / 1,6-glucan, the vitamin C, and the vitamin E are pre-blended to the feed base for fish farming, and prepared and molded according to a conventional method. The mixed feed prepared and molded as the feed base for fish farming may be coated with the grape seed extract, the β-1,3 / 1,6-glucan, the vitamin C, and the vitamin E. You may add by methods, such as.

  There is no restriction | limiting in particular as an administration method of the said feed for functional fish farming, Although it can select suitably according to the kind, growth stage, etc. of the fish to administer, It is preferable to administer continuously from the time of a feed start.

There is no restriction | limiting in particular as control fish which administer the said feed for functional fish farming, and prevent the infection by the said Flavobacterium genus bacteria, It can select suitably according to the objective, For example, a salmonid salmonid ( Rainbow trout, calaft trout, white salmon, coho salmon, char, salmon, etc.) , Perch (british, red sea bream, etc.), eel eyes, goldfish eyes, and cod eyes. Among these, the feed for functional fish farming is suitable as a feed for salmon, carp and perch fish, more suitable as a feed for salmon and carp fish, and feed for rainbow trout fry Is particularly suitable.
The feed for functional fish farming is suitable as a feed for fish having commercial value such as farmed fish and ornamental fish because it can prevent infections caused by the Flavobacterium bacteria and prevent fins and body surface defects. .

(Evaluation for prevention of Flavobacterium infection)
The infection prevention effect of the Flavobacterium genus bacterium can be determined based on the area change due to the fin defect of the fish.
As the fin for measuring the area, any one of a dorsal fin, a chest fin, a tail fin, a prone fin, and a sputum may be used, but either a dorsal fin or a tail fin is preferable because observation is easy and occurrence frequency of defects is high.

<Measurement method>
The area of the fin can be measured by anesthetizing the measurement control fish with eugenol and observing it using a stereomicroscope or the like.
The comparison control can be statistically obtained from the correlation between the fin area of a normal solid in which no defect is observed, the base (root) of the fin according to the growth stage, and the length. Based on the statistically obtained fin area and the correlation between the fin base (root) and the fin length, the fin defect rate of the measured fish can be evaluated.

<Evaluation method>
From the comparison control, the onset of the Flavobacterium genus infection can be evaluated by determining the fin defect rate of the test fish. For example, the fin area of a fish body having a fin defect is compared with the fin area of the comparative control, and when the fin defect rate is less than 30% (when the fin residual rate is 70% or more), The case where the defect rate is 30% or more and less than 70% (when the fin remaining rate is 30% or more and less than 70%) is “moderate”, and the case where the fin defect rate is 70% or more (the fin remaining rate is 30%) Can be evaluated as “severe”.

When there is a fish body that is evaluated as “mild” or “medium” based on the above evaluation, the functional fish feed is administered to the cultured fish that is bred in the same aquarium as the fish body. By carrying out the improvement, it is possible to more reliably prevent the Flavobacterium infection from spreading and to suppress the occurrence of fin defects.
Examples of the improvement of the breeding environment include a method of reducing the breeding density, a method of increasing the water flow rate, and a method of increasing the feeding rate.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example)
The breeding tank made of vinyl chloride shown in FIG. 1 was installed indoors, and sections A to E were accommodated, each containing 190 rainbow trout fry having an average weight of 1.4 g in one section of the tank shown in FIG. The rainbow trout fry in each section was fed with a feed having the composition shown in Table 1 below and reared for 30 days. Water flow was performed at a water volume of 39.4 L and a water depth of 10 cm in each compartment.
The average water temperature during the breeding period was 14 ° C.

・ブドウ種子抽出物：ＫＰＡ−Ｆ（キッコーマン（株）製）
・β‐１，３／１，６‐グルカン：マクロガード（バイオテック社製）
・ビタミンＣ：Ｌ−Ａｓｃｏｒｂｉｃ ａｃｉｄ（江芳江山制葯有限公司製）
・ビタミンＥ：メイロング（（株）科学飼料研究所製）
・配合飼料組成：魚粉６２質量％、小麦粉２５質量％、脱脂大豆粕５質量％、魚油５質量％、ビタミン・ミネラル混合物３質量％。ただし、ビタミン・ミネラル混合物中のビタミンＣ配合率は２．４質量％、ビタミンＥ配合率は１．０５質量％であるため、該配合飼料組成中のビタミンＣ配合率は０．０７２質量％、ビタミンＥ配合率は０．０３１５質量％である。

-Grape seed extract: KPA-F (manufactured by Kikkoman Corporation)
・ Β-1,3 / 1,6-glucan: Macroguard (Biotech)
・ Vitamin C: L-Ascorbic acid (manufactured by Jiangjiang Mountain Control Co., Ltd.)
・ Vitamin E: Maylong (manufactured by Scientific Feed Research Institute)
Formula feed composition: 62% by mass of fish meal, 25% by mass of wheat flour, 5% by mass of defatted soybean meal, 5% by mass of fish oil, and 3% by mass of a vitamin / mineral mixture. However, since the vitamin C blending ratio in the vitamin / mineral mixture is 2.4 mass% and the vitamin E blending ratio is 1.05 mass%, the vitamin C blending ratio in the blended feed composition is 0.072 mass%, The vitamin E content is 0.0315% by mass.

On the 30th day from the start of breeding, the survival rate (%), weight gain (g), and feed efficiency (%) of each of the sections A to E were measured. The feed efficiency was determined from the following formula (1). The results are shown in Table 2.
Feed efficiency (%) = weight gain (g) × 100 / feed dose (g) Formula (1)

  In addition, on the 30th day from the start of breeding, the fish taken out from the aquarium was anesthetized with Eugenol (FA100, manufactured by Dainippon Pharmaceutical Co., Ltd.), and the state of fins was observed using a stereomicroscope. The degree of deficiency of the dorsal fin was evaluated. The results are shown in Table 2.

(1) Abnormal rate of fins The dorsal fin, caudal fin, pectoral fin, and prone fin of the fish were observed, and the ratio of the number of individuals having a defect in any of the fins was calculated for each section to obtain an abnormal rate (%).
Moreover, the abnormality rate of division BD was computed as a relative abnormality rate with respect to the abnormality rate of the division A which is not administering the said functional fish farm feed as a comparison division.

(2) Degree of dorsal fin defect For each section, the average value of the dorsal fin area of normal individuals with no fin defects was determined and used as the reference area. The dorsal fin area of the individual with the defect was compared with the reference area to determine the defect rate. Based on the value of the defect rate, the defect degree was evaluated according to the following evaluation criteria.
Table 2 shows the ratio of each defect degree in the individual having the defect.
〔Evaluation criteria〕
Mild: Defect rate is less than 30% Medium: Defect rate is 30% or more, less than 70% Severe: Defect rate is 70% or more

Moreover, the commercial value as cultured fish was evaluated by the following method by appearance observation. Table 3 shows the ratio (%) of each evaluation.
〔Evaluation criteria〕
◎: Fin defects are not found and the product value is very high ○: Fin defects are slightly observed but there is commercial value △: Fin defects are found and the product value is low ×: Fin defects Is large and has no commercial value

  From Table 2 and Table 3, the rainbow trout fry raised by feeding the functional fish farm feed of the present invention has a low abnormal rate of fins, and in particular, since the loss of fins is suppressed, the commercial value may be high. all right. Moreover, since the rainbow trout fry reared by feeding with the functional fish farm feed has few defects in fins, it was revealed that infection with Flavobacterium bacteria was prevented.

(2) Identification of Flavobacterium genus-Isolation of bacteria and infection test-
From the rainbow trout fry that observed caudal fins in the above examples, select 5 individuals with no caudal defect (normal individuals) and 5 individuals with deficiency in caudal fin (deficient individuals rated moderate to severe), Each caudal fin (the remaining part of the deficient individual) was excised and collected. Each caudal fin was housed in a plastic tube containing sterilized physiological saline, and homogenized with a homogenizer pestle (for 1.5 mL; 1005-39, manufactured by ASONE Co., Ltd.) to obtain a sample solution.
The sample solution was prepared in 5 stages in a 10-fold dilution series using sterile physiological saline. 100 μL of each diluted solution was applied to Cytoferga agar medium and cultured at 15 ° C. for 1 week. Colonies were randomly collected from those in which about 100 colonies could be confirmed per medium, and 10 strains (A1 to 10) derived from normal individuals and 10 strains (B1 to 10) derived from defective individuals were obtained. These were subcultured on a cytoferga agar medium at a temperature of 15 ° C.
10 strains (A1-10) derived from the normal individuals and 10 strains (B1-10) derived from the defective individuals were each inoculated into a cytophaga liquid medium and cultured at 15 ° C. for 24 hours. 1 mL of the culture solution was collected.

  For the test, caudal fins were excised from 20 normal individuals that were confirmed to be free of defects in the caudal fin using a stereomicroscope to obtain a caudal fin for infection test. The surface of the infection test tail pad is wiped with Kimwipe (registered trademark) containing 70% ethanol to remove body surface mucus, and then put into each culture solution one by one, and placed in a 15 ° C incubator. Let stand for 1 hour. Then, the test tail fin was taken out and placed on a medium consisting of only 1.5% (w / w) agar for bacteria, which was incubated in a thermostat at 15 ° C. for 1 week. The state of the caudal fin one week later was observed with a stereomicroscope. The results are shown in Table 4. Moreover, the photograph of the caudal fin which administered the culture solution of A-1 and B-1 is shown in FIG.

−：尾鰭に欠損がみられなかった、又はごくわずかに欠損がみられた
＋：尾鰭に欠損がみられた

-: There was no defect in the caudal fin, or a slight defect was observed. +: A defect was observed in the caudal fin.

  From Table 4 and FIG. 3, there was no change in the caudal fin inoculated with cells (A1 to 10) derived from normal individuals, or even if there were defects, the cells derived from the defective individuals All caudal fins inoculated with (B1 to 10) were in a state in which a defect occurred and the caudal tissue collapsed and melted. This suggests that the defect of caudal fin is a phenomenon caused by bacterial infection. Moreover, it was estimated that the colony of the microbial cell (B1-10) derived from the said defective individual | organism | solid is a Flavobacterium genus bacteria from a color, a shape, and the form of a microbe.

-Identification of bacteria-
10 strains (A1-10) derived from the normal individuals and 10 strains (B1-10) derived from the defective individuals were each inoculated into a cytophaga liquid medium and cultured at 15 ° C. for 24 hours. Bacterial cells were precipitated from the culture solution by centrifugation (10,000 g, 5 minutes). A 5% Chelex solution (Chelex 100, manufactured by Sigma) was added to the obtained cells and mixed well, and then incubated at 55 ° C. for 20 minutes in a constant temperature water bath. Subsequently, after stirring with a vortex mixer, it was placed in boiling water for 20 minutes, and insoluble matters were precipitated by centrifugation (10,000 g, 10 minutes), and the supernatant was recovered.

Using the obtained supernatant, bacterial cells were identified by the PCR method. Flavobacterium columnare, and identification of Flavobacterium psychrophillum is, Triyano et al. , Fishpathology, 34 (4), 217-218 (1999), and Toyama et al. , Fishpathology, 29 (4), 271-275 (1994).
The reaction solution after the PCR reaction was electrophoresed using a 1.5% agarose gel . columnar specific genes, and F. The presence or absence of a psychromillum specific gene was confirmed. The results are shown in Table 5.

＋：菌体特異的遺伝子の増幅がみられた
−：菌体特異的遺伝子の増幅がみられなかった

+: Bacterial cell-specific gene amplification was observed-: Bacterial cell-specific gene amplification was not observed

From Table 5, B1, B3, and B9 are F.I. columnar , and B5, B6, and B7 are F.I. Identified as psichromilum . Amplification of any cell-specific genes was not observed B4, and B9 are, F. columnare and F.A. Although it was not any of psichromilum , it is considered to be a bacterium of the genus Flavobacterium from the appearance characteristics.
From these results, it was found that the fin deficiency was caused by bacterial infection of the genus Flavobacterium, and the fin deficiency could be prevented by preventing bacterial infection of the Flavobacterium genus.

  Further, when the same test was performed on the surface of the infection test tail fin without wiping but leaving the body surface mucus, no defects occurred in any of the test tail fins. From this, it was shown that fin defects may be caused by infecting and proliferating bacteria of the genus Flavobacterium at a site where mucus was removed for some reason, and producing a substance that dissolves fins.

(Example 2)
The breeding tank made of vinyl chloride shown in FIG. 1 was installed indoors, and compartments A to D were provided in which 200 rainbow trout fry having an average weight of 0.9 g were accommodated in one compartment shown in FIG. The rainbow trout fry in each section was fed with feed having the composition shown in Table 6 below and reared for 30 days. Water flow was performed at a water volume of 39.4 L and a water depth of 10 cm in each compartment.
The average water temperature during the breeding period was 14 ° C.

・ブドウ種子抽出物：ＫＰＡ−Ｆ（キッコーマン（株）製）
・β‐１，３／１，６‐グルカン：マクロガード（バイオテック社製）
・配合飼料組成：魚粉６２質量％、小麦粉２５質量％、脱脂大豆粕５質量％、魚油５質量％、ビタミン・ミネラル混合物３質量％。ただし、ビタミン・ミネラル混合物中のビタミンＣ配合率は２．４質量％、ビタミンＥ配合率は１．０５質量％であるため、該配合飼料組成中のビタミンＣ配合率は０．０７２質量％、ビタミンＥ配合率は０．０３１５質量％である。

-Grape seed extract: KPA-F (manufactured by Kikkoman Corporation)
・ Β-1,3 / 1,6-glucan: Macroguard (Biotech)
Formula feed composition: 62% by mass of fish meal, 25% by mass of wheat flour, 5% by mass of defatted soybean meal, 5% by mass of fish oil, and 3% by mass of a vitamin / mineral mixture. However, since the vitamin C blending ratio in the vitamin / mineral mixture is 2.4 mass% and the vitamin E blending ratio is 1.05 mass%, the vitamin C blending ratio in the blended feed composition is 0.072 mass%, The vitamin E content is 0.0315% by mass.

On the 30th day from the start of the breeding, the survival rate (%), weight gain (g), and feed efficiency (%) of each of the sections A to D were measured in the same manner as in Example 1, and the fish in each section were measured. The abnormal rate of fins and the degree of deficiency of dorsal fin were measured in the same manner as in Example 1. The results are shown in Table 7.
Moreover, the commercial value as a cultured fish was evaluated in the same manner as in Example 1. The results are shown in Table 8.

  From the results of Tables 7 and 8, the effect of reducing the abnormal rate of fins can be obtained by administering a grape seed extract or a feed containing β-1,3 / 1,6-glucan alone. , The administration of the functional fish culture feed of the present invention comprising both grape seed extract and β-1,3 / 1,6-glucan can significantly reduce the fin deficiency, It was found that the commercial value of cultured rainbow trout can be increased.

(Example 3)
In rainbow trout (average body weight 1.2 g) bred in a 400 liter concrete tank, many individuals with moderate fin deficiency began to appear, and 30 to 40 fish drowned per day. Flavobacterium genus bacteria ( F. columnare and F. psychophilum ) were detected from dying rainbow trout in the same manner as in Example 1.
Sections A and B were provided in which 400 rainbow trouts obtained from this tank were accommodated in 400 sections in one section of the vinyl chloride breeding tank shown in FIG. The rainbow trout in each section was fed with feed having the composition shown in Table 1 below and reared for 60 days.
The average water temperature during the breeding period was 14 ° C.

・ブドウ種子抽出物：ＫＰＡ−Ｆ（キッコーマン（株）製）
・β‐１，３／１，６‐グルカン：マクロガード（バイオテック社製）
・ビタミンＣ：Ｌ−Ａｓｃｏｒｂｉｃ ａｃｉｄ（江芳江山制葯有限公司製）
・ビタミンＥ：メイロング（（株）科学飼料研究所製）
・配合飼料組成：魚粉６２質量％、小麦粉２５質量％、脱脂大豆粕５質量％、魚油５質量％、ビタミン・ミネラル混合物３質量％。ただし、ビタミン・ミネラル混合物中のビタミンＣ配合率は２．４質量％、ビタミンＥ配合率は１．０５質量％であるため、該配合飼料組成中のビタミンＣ配合率は０．０７２質量％、ビタミンＥ配合率は０．０３１５質量％である。

-Grape seed extract: KPA-F (manufactured by Kikkoman Corporation)
・ Β-1,3 / 1,6-glucan: Macroguard (Biotech)
・ Vitamin C: L-Ascorbic acid (manufactured by Jiangjiang Mountain Control Co., Ltd.)
・ Vitamin E: Maylong (manufactured by Scientific Feed Research Institute)
Formula feed composition: 62% by mass of fish meal, 25% by mass of wheat flour, 5% by mass of defatted soybean meal, 5% by mass of fish oil, and 3% by mass of a vitamin / mineral mixture. However, since the vitamin C blending ratio in the vitamin / mineral mixture is 2.4 mass% and the vitamin E blending ratio is 1.05 mass%, the vitamin C blending ratio in the blended feed composition is 0.072 mass%, The vitamin E content is 0.0315% by mass.

In section A, rainbow trout fed with the mixed feed increased in individuals with severe fin defects, and drowned continuously, and 28% died after 60 days. On the other hand, the rainbow trout fed the functional fish farming feed of the present invention in section B showed a recovery of fin deficiency in mild fin deficient individuals, the number of fin deficient individuals decreased, and the mortality rate was 3%. .
Therefore, the functional fish farm feed of the present invention can prevent fin deficiency of fed cultured fish and the like, and also has a recovery effect on Flavobacterium bacterium infection due to the preventive effect on Flavobacterium bacterium infection. In particular, it has been found that the survival rate of cultured fish can be increased by improving the survival rate of larvae and larvae, and the cultured fish can be maintained in a state of high commercial value.

  The functional fish farm feed of the present invention can be administered as a normal feed, does not contain harmful substances that remain or accumulate in the fish body, can prevent infection by Flavobacterium bacteria, and can prevent fin damage Therefore, it is suitable as a feed for cultured fish, and particularly suitable as a food for edible cultured fish and ornamental fish with high commercial value.

FIG. 1 is a schematic view showing the whole rearing water tank used in Examples 1 and 2. FIG. 2 is a schematic diagram showing one section of the breeding water tank of FIG. FIG. 3 is a photograph of the caudal fin administered with the culture solutions of A-1 and B-1 in Example 1.

Explanation of symbols

10 Water injection section 11 Water tank (compartment)
12 Drainage net 13 Drainage port

Claims (5)

  0.1% to 0.2% by weight grape (Vitis spp.) Seed extract, and 0.1% to 0.2% by weight β-1,3 / 1,6-glucan, A functional fish feed characterized by being used for recovery of fin damage caused by Flavobacterium genus bacteria.   The functional fish farm feed according to claim 1, wherein the grape seed extract contains 38 mass% to 60 mass% of proanthocyanidins.   The functional fish feed according to any one of claims 1 to 2, comprising 0.5% to 1.0% by weight of vitamin C and 0.1% to 0.2% by weight of vitamin E.   The feed for functional fish farming according to any one of claims 1 to 3, which is used for recovery of fin damage caused by Flavobacterium genus bacteria of salmonid fish and cyprid fish. The functional fish farm feed according to any one of claims 1 to 4 , which is used for recovery of fin damage caused by at least one of Flavobacterium columnum and Flavobacterium physochyllium.

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