JPH0662760A - Oil and fat composition enriched with nutrient feed organism for larva and juvenile fish, feed organism for larva, and the like, and raising and cultivation of larva and juvenile fish using the organism - Google Patents

Abstract

PURPOSE:To keep sufficient nutrition effect by including specific amounts of an omega3 highly unsaturated fatty acid in combination with fatty acids belonging to the group of saturated fatty acid and polybasic unsaturated fatty acid in a fatty acid composition. CONSTITUTION:The fatty acid composition contains (A) >=15% of omega3 highly unsaturated fatty acid (excluding docosahexaenoic acid) for the enrichment of nutrient and (B) fatty acids belonging to the group composed of 8-16C saturated fatty acid and >=18C polybasic unsaturated fatty acid having a chain length shorter than that of the omega3 highly unsaturated fatty acid. The amount of the component B is >=15% based on the omega3 highly unsaturated fatty acid. Emulsified oils (e.g. oil and fat of fish or shellfish) used for the nutrient enrichment of conventional feed organism can be enriched with the omega3 highly unsaturated fatty acid at a high level by this process to enable the maintenance of a sufficiently high nutrient-enriching effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed bionutrition-enriched oil / fat composition for fry, a feed organism for fry that has been fortified by the composition, and a method for aquaculture of fry using the same.

[0002]

2. Description of the Related Art Hitherto, zooplankton such as Shiomizutsubo rotifer (hereinafter abbreviated as rotifer) and Artemia (brine shrimp) have been mainly used as an initial feed for fry. As the nutritional value of these zooplankton, the content of ω3 polyunsaturated fatty acids becomes a problem, and for several hours to 24 hours, oils and feeds containing ω3 polyunsaturated fatty acids are fed to the zooplankton to feed the zooplankton. The method of feeding the juvenile fish after strengthening the ω3 polyunsaturated fatty acid content is used (JP-A-57-12).
937, JP-A-3-277241, JP-A-3-2772
42, JP-A-3-123449). On the other hand, in recent studies, among ω3 highly unsaturated fatty acids, docosahexaenoic acid (hereinafter abbreviated as DHA) has a higher essential fatty acid effect than other ω3 highly unsaturated fatty acids such as eicosapentaenoic acid (hereinafter abbreviated as EPA). Became clear (Journal of Fisheries Science, Vol. 55, No. 9, pp. 1635 to 1640, etc.), and attention has been paid to the enhancement of DHA to feed organisms. However, the conventional fortification method has not always been able to fortify the larvae to a level satisfying the requirement for ω3 highly unsaturated fatty acids. Especially for Artemia, D
HA was decomposed quickly (Abstracts of the Autumn Meeting of the 1st Annual Meeting of the Fisheries Society of Japan in 1991, p. 120), and a sufficient nutritive effect could not be maintained depending on the timing of feeding nutrition-enriched artemia to larvae.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is to efficiently enhance ω3 highly unsaturated fatty acids represented by DHA to a high level in feed organisms. It is an object of the present invention to provide an oil and fat composition capable of being produced, and a feed organism fortified thereby. Another object of the present invention is to provide a method for aquaculture of juvenile fish by feeding them.

[0004]

This object can be solved by the following means. That is, in the present invention, in the fatty acid composition, 15% or more of ω3 highly unsaturated fatty acid (excluding docosahexaenoic acid) for the purpose of nutritional enrichment and C8-
For fry, characterized by containing 15% or more of fatty acids belonging to the group consisting of C16 saturated fatty acids and C18 or higher ω3 fatty acids having a shorter chain than the ω3 fatty acids. It is a feed bionutrition enriched oil composition. The present invention also relates to the case where the ω3 fatty acid is docosahexaenoic acid (DHA), wherein DHA is 1 in the fatty acid composition.
5% or more and C8 to C16 saturated fatty acids and C1
Fatty acids belonging to the group consisting of 8- to C22 polyunsaturated fatty acids (excluding DHA and eicosapentaenoic acid (EPA)) are 15% or more of DHA or / and EPA.
Is 60% or more with respect to DHA, and is a feed bionutrition-enriched oil / fat composition for larvae.

The present invention further comprises a dietary organism for fry which is fortified based on the fatty acid composition of the oil and fat composition.
A method for aquaculture of fry fish, which is a feed organism for fry fish having an enhanced HA content, and further comprises aquaculture of fry fish using the feed for fry fish.

According to the present invention, emulsified oils, that is, fish oils and fats such as seafood oils and fats, which have been conventionally used for nutritional enhancement of feed organisms, are more efficiently than partially refined oils obtained by molecular distillation for the purpose of fortifying ω3 highly unsaturated fatty acids. ω3 highly unsaturated fatty acids,
In particular, high-level nutritional enhancement of DHA becomes possible. Also,
By cultivating juvenile fish using such a sufficiently enriched feed organism, it is possible to efficiently produce fish seeds and seedlings, and it is possible to produce highly viable aquatic seedlings.

In the following, the present invention aims to enhance nutrition.
The case where the 3 highly unsaturated fatty acid is DHA will be described in detail, but the principle is the same for fatty acids other than DHA.
However, in the case of DHA, the relationship with EPA is more specific than in other cases.

The inventors of the present invention have conducted earnest research to realize efficient nutritional fortification of ω3 polyunsaturated fatty acids of feed organisms, in particular, DHA, and as a result, specific amount of specific fatty acid in DHA for nutritional enrichment was determined. By coexisting, it was found that DHA can be extremely effectively accumulated in the feed organism by the administration of the same DHA content as compared with the case where it is not present, and the present invention has been completed. This effect is particularly remarkable in artemia and the like, where metabolism of ω3 polyunsaturated fatty acids is fast and stable nutritional enrichment is difficult, and a specific fatty acid composition effectively acts on the metabolic system of the feed organism, and DHA It can be seen that it enables preferential accumulation in the body.

[0009] First, the "feeding organisms for fry fish" in the feed bionutrition-enriched oil and fat composition for fry of the present invention include not only freshwater fish such as sweetfish and sea fish such as red sea bream and flatfish.
Crustaceans such as shrimp and crab, molluscs such as squid and octopus, etc. ω3
It refers to an organism that can serve as a feed for organisms that require highly unsaturated fatty acids as essential fatty acids, regardless of species. For example,
Examples thereof include artemia, rotifer, daphnia, and copepods.

In particular, as described in the prior art, the present invention is effective for feed organisms such as artemia, which have a fast metabolism of ω3 polyunsaturated fatty acids and are difficult to stably fortify.

Further, "nutrition fortification" refers to fortification for the purpose of fortifying ω3 highly unsaturated fatty acids, especially DHA.

The term "oil / fat composition" refers to free fatty acids as well as triglycerides, diglycerides, monoglycerides, waxes, esters such as methyl esters and ethyl esters, derivatives such as complex lipids such as phospholipids, or a mixture thereof.

Next, the fatty acid composition in the oil / fat composition, which is a feature of the present invention, will be described.

That is, DHA is 15% in the fatty acid composition.
Above, C8-C16 saturated fatty acids and C18-
Fatty acids belonging to the group consisting of C22 polyunsaturated fatty acids (excluding DHA and EPA) account for 15% of DHA
The above or / and EPA is contained in 60% or more with respect to DHA, but the important thing in this fatty acid composition is to specify a specific fatty acid in DHA without enriching only DHA for the purpose of fortification. It is in the amount of coexistence. Specific fatty acids include one or more saturated C8 to C16 fatty acids (abbreviated as C8-16S) and C18 to C22 polyunsaturated fatty acids (excluding DHA and EPA) (C18-
Abbreviated as 22PU. ) Selected from one or more and EPA. Coexistence amount with DHA is C8-16S, C18-22P
The standard for U is 15% with respect to DHA and 60% for EPA. C8-16S alone or C18-22PU alone may be 15% or more of DHA, or a mixture of both may be 15% or more of DHA. Alternatively, instead of or in addition to these, EPA may coexist at 60% or more of DHA. If neither condition is met, it will be difficult to effectively accumulate DHA in the feed organism. Preferably, 20% or more of C8-16S or / and C18-22PU coexists with DHA. There is no particular upper limit on the amount of coexistence, but as long as the purpose is to strengthen DHA, it does not make much sense to exist in a considerably larger amount than DHA. Further, there is no problem even if various fatty acids are contained in addition to the above-mentioned coexisting fatty acids. Both C8-C16 saturated fatty acids and C18-C22 polyunsaturated fatty acids are effective, but C8-C16 unsaturated fatty acids and C18
~ C22 monounsaturated or saturated fatty acids have little or no effect. The specificity of such a specific fatty acid in the presence of DHA has never been known. Further, the effect differs depending on the type of coexisting fatty acid.

The technical reasons for this effect are still in the estimation stage, but the following three can be considered.

(1) It is considered that the coexistence of fatty acids that are more easily decomposed than DHA causes them to be decomposed preferentially, resulting in more accumulation of DHA. There are no studies on rotifer and artemia, but in some animals, the specificity of the enzyme (acyl-CoA synthetase) that acts in the first step of fatty acid degradation depends on the chain length of fatty acids, and C12 is the most likely substrate. There is (Biochim.Biophys.
Acta. 796 , 1-10 (1984)).

(2) The reason why the DHA accumulation effect differs depending on the type of coexisting fatty acid is presumed to be due to the substrate specificity of the acyl CoA transferase.

(3) When DHA is decomposed, EPA and α
-Produces a shorter chain ω3 highly unsaturated fatty acid than linolenic acid as an intermediate for decomposition. Therefore, it is presumed that the coexistence of these fatty acids puts a brake on the decomposition of DHA.

Fatty acids to be coexisted with DHA include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, and / or linoleic acid, linolenic acid,
One or more of arachidonic acid, EPA and the like can be mentioned, and among them, lauric acid, myristic acid, linolenic acid, linoleic acid and the like can be mentioned as inexpensive and highly effective. In addition to free fatty acids, these fatty acids can be used as triglycerides, diglycerides, monoglycerides, waxes, esters such as methyl esters and ethyl esters, and derivatives such as phospholipids. Therefore, the coexistence form with DHA may be a mixture of free fatty acid and glyceride, or a mixed glyceride form with DHA.

The amount of DHA present in the fatty acid composition is 15% or more, preferably 25% or more, and more preferably 50% or more. This is because the oil / fat composition of the present invention is intended to enhance the DHA of feed organisms, and therefore a small amount of DHA does not meet the purpose. The fatty acid used in the present invention may be obtained from fish or shellfish, or may be derived from microorganisms or algae regardless of its origin.

Next, in order to fortify a feed organism for larvae using the oil composition of the present invention, each fatty acid may be premixed prior to the fortification, or separately. You may throw in a nutrient fortification tank. That is, as long as the fatty acid composition of the oil / fat composition is eventually achieved in the nutrient fortification tank, any means may be used.

Therefore, the oil or fat composition may be prepared in an emulsified oil type. In the work of nutrition enhancement,
Emulsified oil type is convenient. In this case, an emulsifier such as lecithins and fatty acid esters may be contained in the oil / fat composition in an amount of about 1 to 10 wt%.

For the nutritional enhancement, the oil and fat composition of the present invention is put into seawater at a temperature of 20 to 30 ° C. in a nutritional fortification tank containing artemia or rotifer etc. from which eggshells have been removed by a conventional method.
It is recommended to perform the operation for several hours to 24 hours. When the oil / fat composition is added, it may be added after being emulsified with a mixer, a homogenizer ultrasonic generator or the like in advance, or may be directly added by using an emulsifier such as lecithins and fatty acid esters in combination. At this time, a bait yeast, a oleaginous yeast, a chlorella or the like may be used in combination.

The method for nutritional enrichment can be carried out based on a conventional method.
0 to 5000 individuals / ml, Artemia with hatched eggs removed and stored in a fortification tank at a concentration of 10 to 300 individuals / ml, and an oil and fat composition of 0.01 to 0.2 mg / m
It may be added at a rate of 1 l and carried out at 28 ° C. for about 12 hours under sufficient aeration. When the oil / fat composition is added after being emulsified, for example, it is added together with chicken egg yolk (about 1 to 10% of the oil / fat) to tap water at a concentration of 3 to 500 mg / ml to emulsify it, and this is fortified. Just put it in.

The DHA content in the feed organism using the oil composition of the present invention is higher than that in the case of using the conventional emulsified oil.
Approximately 10% despite the same dose of DHA
The accumulated amount of DHA increases by about 100%.

[0026] By using the feed organisms fortified in this way, freshwater fish such as sweetfish, marine fish such as red sea bream and flounder, shrimp
Cultivation of organisms that require ω3 polyunsaturated fatty acids such as crustaceans and other molluscs such as squid and octopus as essential fatty acids significantly improves survival rate, growth, and vitality as compared with conventional methods. The feeding method can be carried out based on a conventional method.

The constitution and effects of the present invention will be described in more detail below with reference to examples of the present invention.

[0028]

【Example】

Example 1 DHA ethyl ester (95%) was mixed with various fatty acid ethyl esters to prepare various oil and fat compositions as shown in Table 1.

All the components of the conventional oil (Easter 85, Oriental Yeast Co., Ltd.) were as follows.

C16: 1 0.3, C18: 0 1.8, C18: 1 0.5, C18: 2 0.7, C18: 3 0.7, C18: 4 0.8, C20: 0 0. 2 C20: 3 0.3, C20: 4 3.1, C20: 5 27.7, C22: 4 0.8, C22: 5 3.6, C22: 6 49.8, C24: 0 0.2 ( %)

[0031]

[Table 1] The rotifers were fortified with the oils 1 to 4 shown in Table 1 and the comparative oils 1 to 4 and the conventional emulsified oil. Rotifers were subcultured with freshwater chlorella as a feed at a density of 1000 individuals / ml and seawater in a 30-liter Panlite aquarium 2
It was housed in 0 liter. 300 ml of 1.5 g of each oil
Was emulsified with a small amount (0.1 g) of chicken egg yolk in tap water, and the mixture was put into the Panlite water tank and then enriched under sufficient aeration at 28 ° C. for 12 hours. Rotifer lipid content (%) per dry weight, DH
The A content (%) was measured. As a comparative example, rotifers before nutritional enrichment were also measured in the same manner. Although the DHA content in each oil was almost the same, the DHA content in the rotifer was higher in the oils 1 to 4 than in the commercially available emulsified oils, as shown in Table 2.

[0032]

[Table 2] Example 2 DHA methyl ester (95%) was mixed with various fatty acid methyl esters to prepare various oil and fat compositions as shown in Table 3.

[0033]

[Table 3] Oils 5 to 9 shown in Table 3, comparative oils 5 to 7 and conventional emulsified oil were used to fortify rotifers under the conditions shown in Example 1. Although the DHA content in each oil was almost the same, the DHA content in the rotifer was higher in oils 5 to 9 than in the conventional emulsified oil, as shown in Table 4.

[0034]

[Table 4] Example 3 DHA ethyl ester (95%) was mixed with various fatty acid ethyl esters to prepare various oil and fat compositions as shown in Table 5.

[0035]

[Table 5] Oils 10 to 13 shown in Table 5, comparative oils 8 to 11,
The conventional rotifer was fortified with the emulsified oil under the conditions shown in Example 1. As shown in Table 6, the DHA content in the rotifer was almost the same, even though the DHA content in each oil was almost the same.
The contents of oils 10 to 13 were higher than those of conventional emulsified oils.

[0036]

[Table 6] Example 4 100 g of DHA ethyl ester derived from tuna oil (purity 65%, manufactured by Nippon Kagaku Feed) was added to lauric acid ethyl ester 14
g, 1 g of lauric acid monoglyceride (manufactured by Taiyo Kagaku, Sunsoft 750) and 5 g of soybean lecithin as an emulsifier were added and mixed to prepare an emulsified oil. Table 7 shows the DHA and EPA contents of this emulsified oil and the conventional emulsified oil.

[0037]

[Table 7] These emulsified oils were used to fortify rotifers under the conditions shown in Example 1. As shown in Table 8, the EPA and DHA contents of the rotifer after fortification were higher than those of the conventional emulsified oil, although the DHA contents of the oils were almost the same.

[0038]

[Table 8] Example 5 Oils 1 to 4 prepared in Example 1 and comparative oils 1 to 4
And the conventional emulsified oil was used to fortify Artemia.
Artemia was prepared by incubating dried eggs from North America in seawater at 28 ° C and removing eggshells at a density of 100 individuals / ml.
It was stored in 20 liters of seawater in a 0 liter Panride aquarium. 1.5 g of each oil was emulsified in 300 ml of tap water together with a small amount of chicken egg yolk, and the mixture was put into the Panlite water tank and then enriched under sufficient aeration at 28 ° C. for 12 hours. The lipid content (%) and DHA content (%) per dry weight of the Artemia after the completion of nutritional enrichment were measured. As a comparative example, the same measurement was performed on Artemia before fortification. As shown in Table 9, the DHA content in Artemia was higher in oils 1 to 4 than in conventional emulsified oils, although the DHA content in each oil was almost the same.

[0039]

[Table 9] Example 6 Artemia was fortified with the oils 5-9 prepared in Example 2, Comparative Examples 5-7 and conventional emulsified oil. The conditions of Artemia fortification were those of Example 5. As shown in Table 10, the DHA content of Artemia after fortification was higher in Oils 5 to 9 than in conventional emulsified oils.

[0040]

[Table 10] Example 7 Oils 10 to 13 prepared in Example 3 and Comparative Examples 8 to 11
And the conventional emulsified oil was used to fortify Artemia.
The conditions of Artemia fortification were those of Example 5. As shown in Table 11, the DHA content of Artemia after fortification was higher in oils 10 to 13 than in conventional emulsified oils.

[0041]

[Table 11] Example 8 Artemia was fortified under the conditions shown in Example 5 using the emulsified oil prepared in Example 4 and the conventional emulsified oil. As shown in Table 12, the EPA and DHA contents in the aluminate after fortification were higher in the product of the present invention than in the conventional emulsified oil, although the DHA contents in each oil were almost the same.

[0042]

[Table 12] Example 9 Red sea bream larvae were bred using the rotifer and Artemia that were fortified in Examples 4 and 8. The present invention group, a non-fortified group and a conventional emulsified oil group were provided as control groups, and the survival rate at the end of the test, the total length, and the vitality were examined. In each test section, 10,000 hatching red sea bream larvae of the age 10 which were bred with marine chlorella rotifer after hatching were housed in a 500-liter Panlite aquarium and bred for 30 days at a water temperature of 19 to 21 ° C. 1 feeding
Three times a day at 8:00 am, noon, and 4:00 pm 100,000 to 1 each
Million rotifers and artemia were fed as the larvae grew. After rearing for 30 days, the number of surviving fish and the total length were measured, and as a vitality test, 100 larvae were taken with a hand net.
It was exposed in the air for 5 seconds, returned to water again, and the survival rate after 24 hours was measured. In addition, the lipid content, EPA and DHA content of the larvae after breeding were measured. Table 13
As shown in (1), in the present invention group, not only the non-enriched group but also the conventional emulsified oil group, the excellent breeding results are obtained. Further, from the results of fish body analysis at the end of rearing shown in Table 14, it can be seen that the fish bodies of the present invention group accumulate a large amount of DHA.

[0043]

[Table 13]

[0044]

[Table 14]

[0045]

As described above in detail, according to the present invention, ω3 polyunsaturated fatty acid, which is an essential fatty acid of fry,
In particular, it is possible to enhance DHA to a feed organism at a high level and with high efficiency, and even if the oil has a purity equivalent to that of a conventionally used emulsified oil, the DHA content in the feed organism is improved. Good results are obtained in the aquaculture of the fry used. In particular, fry bred bred with a feed organism having a high DHA content have high vitality, and thus fish seedlings with high seedling quality can be obtained.

When the purpose is to strengthen ω3 polyunsaturated fatty acids other than DHA, it can be carried out in the same manner as DHA. That is, a certain amount of a C8 to C16 saturated fatty acid that is more easily decomposed than an ω3 highly unsaturated fatty acid for the purpose of nutritional enrichment and / or a constant amount of a polyunsaturated fatty acid having a chain of C18 or more shorter than the ω3 highly unsaturated fatty acid coexist. You can do it. Therefore, it is perfectly acceptable to replace ω3 polyunsaturated fatty acids other than DHA with DHA or to include them together with DHA in the oil and fat composition as an active ingredient.

Claims (5)

[Claims] 1. A fatty acid composition for the purpose of fortifying ω
15% or more of 3 highly unsaturated fatty acids (excluding docosahexaenoic acid) and C8 to C16 saturated fatty acids and C
A fatty acid belonging to the group consisting of polyunsaturated fatty acids having a chain length of 18 or more and a shorter chain than the fatty acid of ω3 is 15 relative to the fatty acid of ω3.
% Or more of the dietary enriched fat and oil composition for larval fish. 2. Docosahexaenoic acid (D
HA) is 15% or more, and fatty acids belonging to the group consisting of C8 to C16 saturated fatty acids and C18 to C22 polyunsaturated fatty acids (excluding DHA and eicosapentaenoic acid (EPA)) are 15% or more with respect to DHA. Alternatively, and / or EPA is contained in an amount of 60% or more based on DHA, a feed bionutrition-enriched oil / fat composition for larvae. 3. The oil / fat composition according to claim 1, which comprises a free fatty acid, a glyceride, an ester thereof or a complex lipid, or a mixture thereof. 4. A feed organism for fry fish having an enhanced DHA content, which is obtained by fortifying the feed organism for fry fish based on the fatty acid composition of the oil or fat composition according to claim 1. 5. A method for cultivating larvae, which comprises cultivating larvae using the feed organism for larvae according to claim 4.