JPS60156349A - Method for raising fish and shellfish and feed therefor - Google Patents

Abstract

PURPOSE:To prevent the blackening in body color of a cultured fish and shell fish, by using glutathione for raising the fish or shellfish. CONSTITUTION:Glutathione is administered in raising a fish or shellfish. The glutathione to be used is a tripeptide expressed by the formula, and produced by the synthetic or fermentation method. Any one of crystalline, roughly purified glutathione and a yeast containing the glutathione may be suitably used. The glutathione can be used by the following modes of use; Previous addition to a formula feed, sprinkling, spreading or adsorbing on a live bait or formula feed in feeding or dissolving the glutathione in water for preparing a paste bait and kneading therein, etc. In this case, the glutathione is conveniently given as a feed containing usually >=0.05% glutathione. Examples of the cultured fish or shellfish to be an object include yellowtail, sea bream, eel, tiger puffer, bastard halibut, AYU (sweet fish), carp, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cultivating fish and shellfish using glutathione, and a fish and shellfish feed containing glutathione.

In recent years, the number of 1ffi species and the amount of fish and shellfish targeted for aquaculture has been increasing every year. However, although the technology for improving productivity in these aquaculture methods has been established, the quality of the produced fish and shellfish, especially the body color, differs from that of natural fish and shellfish, and the This causes a significant drop in product value.

Regarding the body color of farmed fish and shellfish, it has been pointed out that there is a lack or weakness of red or yellow body color, and the phenomenon of blackening of the entire fish body. It has been clarified that the former is caused by a lack of carotenoid substances in the feed, and in fact, synthetic β-carotene and canthaxanthin, or krill, spirulina, chlorella, etc. that contain natural carotenoid substances are The color of the body has improved. On the other hand, the latter is said to be caused by the effects of sunlight due to rearing in shallow water and stress caused by the rearing environment such as high stocking density. has been applied, and a certain degree of suppressive effect on body darkening has been obtained.

However, the above-mentioned measures are still not sufficient, as even when carotenoid pigments are administered, the fish turn red-black, parts of the body that are originally white turn blackish, and black streaks become noticeable when cooked as sashimi. Furthermore, sun cover and bottom cages require additional material costs and are fraught with problems, such as requiring complicated work in daily aquaculture management.

The present inventors focused on the fact that the main causes of darkening of the body color of these i-cultured fish and shellfishes are the increase in melanin pigment and the diffusion of melanin pigment within melanophores, and found that the inhibitory effect on melanin production is As a result of various rearing tests conducted to examine effective means for preventing darkening of the body color of cultured fish and shellfish using a certain substance, the present invention was completed by discovering that administration of glutathione showed a remarkable effect.

That is, the first aspect of the present invention is a method for cultivating fish and shellfish characterized by using glutathione, and the second aspect of the present invention is a fish feed containing 0.025% by weight or more of glutathione. be.

Glutathione used in the present invention is a tripeptide represented by the following formula, and is produced by a synthetic method or a fermentation method.

In the present invention, any of crystalline glutathione, crude 111[glutathione, yeast containing glutathione, etc.] can be suitably used. Crudely purified glutathione includes an aqueous extract of glutathione-containing yeast and dried glucthione-containing products at various stages before crystallization. Possible ways to use it include adding it to compound feed in advance, scattering, spreading, or adsorbing it on raw feed or compound feed during feeding, and dissolving glutathione in the water used to prepare the feed. Conveniently, it is fed as a feed containing 0.025% or more of glutathione. Furthermore, similar effects can be obtained by administering the drug in the form of a bath, injection, tablet, etc., in addition to feed.

Target farmed seafood includes yellowtail, sea bream, and eel.
Examples include fish such as striped horse mackerel, puffer fish, flounder, sweetfish, carp, and trout; crustaceans such as sea bass and prawn; and shellfish such as abalone, botate snail, and oyster.

The dosage is 2 per kg of cultured fish and shellfish body weight per day.
Qmg to 1.000mg, and the administration period is preferably 1 week to 6 months before shipping from both an effective and economical standpoint. If the amount is less than 29 mg, the improvement in body color will be insufficient, while if it is administered in excess of 1,000 mg, no more significant effect will be seen and the economic burden will be heavy, which is not practical.

When using yeast containing glutathione, the content is approximately 1%
(based on dry bacterial weight) or above, and the dosage may be determined by taking into account the glutathione content in the yeast used. Conventionally, torula yeast and brewer's yeast have been used as feeding materials, but these are used to supply trace nutrients such as protein sources, and there are no examples that suggest the effects of glutathione. There are no examples where the content was clearly specified.

As far as the present inventors have measured, the glutathione content of these feed and feed yeasts was 0.1% or less. TsutomuThese yeasts are added to feed at most 10%, and in order to achieve the effects of the present invention, addition of 25% or more is required, which cannot be used as feed from the viewpoint of palatability and nutritional balance.

According to the present invention, it is only possible to prevent darkening of the body color, and fI
Improvement effects are also observed on the debility of E-breeding fish, specifically, decreased liver function, decreased appetite, etc. That is, by carrying out the present invention, it is expected that at the same time as improving body color, debility caused by decreased liver function in cultured fish will be improved, and in healthy cultured fish, disease and debility will be prevented by enhancing liver function. be done.

Next, the present invention will be further explained with reference to Examples, but it goes without saying that the present invention is not limited to these in any way.

Example 1 A red sea bream breeding test was conducted as follows. The feed for sea bream aquaculture having the composition shown in Table 1 was formed into pellets and used as a control feed. Krill meal was added as a carotenoid pigment source. Eighty red sea bream were used in each group, consisting of 11 fish weighing over 200 g.

The test feed in Table 1 contained 10% of glutathione compared to the control feed above.
An aqueous solution of 60 mA was uniformly sprayed and adsorbed during feeding, and glutathione was added to the daily dose of 426 g of the control feed at 6.00 mA.
It was prepared so that it contained g.

Using control feed and test feed, 2m (length) x 2m (width) x
Red sea bream were raised in a 2 m (deep) cage for 30 days. Sunshades were installed in the fish preserves in all wards.

The breeding results are summarized in Table 2. As a result of this test, it was confirmed that the administration of glutathione prevented blackening, brightened the body color, and produced healthy red sea bream similar to those found in nature.

Table 2 *1. Calculation was based on the fish weight at the start of the test.

Example 2 A red sea bream breeding test was conducted as follows. Mixed feed mash for feeding live bait was split according to the formulation shown in Table 3. At the time of feeding, the feed ingredients shown in Table 4 were mixed, ground, and minced.

The size of the fish tank is 3m (length) x 3m (width) x 3.2m (
A sunshade was installed in each case (deep), and red sea bream were reared for 30 days. There were 11 red sea bream fish weighing over 300g, 10 in each area.
Five fish were used. After the test, the fish flesh was observed, paying attention to the body color and the body color 12 hours after being killed immediately, and the fish meat was cut into three pieces, paying attention to the black streaks seen on the cut surfaces.

Table 3 *Glutathione content in glutathione-containing yeast is 4.
0% by weight, the glutathione content in beer yeast is 0.1
Weight% (detection limit) or less.

Table 4 The breeding results and test results are summarized in Table 5.

The results of this study confirmed that administration of glutathione improved body color, post-mortem body color, and fish meat color.

Table 5 *1 Calculated based on the fish weight at the start of the test.

Example 3 A red sea bream breeding test was carried out under the same conditions as Example 2, except that the feed shown in Tables 3 and 4 was used and a daily newspaper was not installed.

The breeding results and test results are shown in Table 6. As a result of this test,
It was confirmed that glutathione administration had the same effect on preventing tanning as oral side placement even without a daily newspaper.

Table 6 *1 Calculated based on the fish weight at the start of the test.

Example 4 A breeding test using eels was conducted as follows. Eel culture feed having the composition shown in Table 7 was prepared and used as a control feed. The test feed was prepared by dissolving 3.0 g of glutathione in 1.2β of water added at the time of formulating the feed so that 3.0 g of glutathione was contained in 11,000 g of feed per day.

Eels weighing approximately 100 g each were used, and the number of eels (approximately 500) was used so that the total weight of each fish was 50 kg. The results after rearing for 90 days are summarized in Table 8.

Table 7 Table 8 As a result of this test, it was confirmed that administration of gluction improved the overall darkened body color characteristic of cultured eels.

Claims (1)

[Claims] 1. A method for cultivating fish and shellfish, characterized by using gluction. 2. Glutathione from 1 kg of seafood, 20 glutathione per day
2. The method of claim 1, wherein ~1,000 mg is administered. 3. The method according to claim 1 or 2, wherein glutathione is mixed into a compounded feed. 4. The method according to claim 1 or 2, in which the aqueous glutathione solution is sprinkled, spread, or adsorbed on feed. 5. The method according to claim 1 or 2, wherein the gluction aqueous solution is used as water for preparing bait. 6. The method according to claim 1 or 2, wherein gluction is administered separately from the feed. 7. The method according to claim 1, wherein the glutathione is crystalline glucthione, crudely purified glucthione, or glutathione-containing yeast containing 1% or more (based on dry bacterial weight) of glutathione. 8. Seafood feed containing 0.02511 ift% or more of glutathione. 9. The feed according to claim 8, wherein the glucthione is crystalline glutathione, crudely purified glutathione, or glucthione-containing yeast containing 1% or more (based on dry bacterial weight) of glutathione.