Feed additive for promoting muscle and gonad development of eriocheir sinensis and application of feed additive

Abstract

The invention discloses a feed additive for promoting muscle and gonad development of eriocheir sinensis and application of the feed additive, and relates to the technical field of aquatic feed. The feed additive comprises cholesterol and omega-3 high unsaturated fatty acid. Each kilogram of the feed comprises the following feed additives by weight: 0.4 to 4.5 g of cholesterol and 3.5 to 4.5 g of omega-3 high unsaturated fatty acid. According to the feed additive, 4.022 g / kg omega-3 high unsaturated fatty acid (omega-3 HUFA) is supplemented into feed containing 4.114 g / kg cholesterol, so that the weight gain rate, the gonad index and the meat percentage of female crabs in the fattening period can be remarkably increased; the protein nutrition deposition capability of gonads and muscles is obviously improved; when the feed added with the feed additive is used in the fattening period of the eriocheir sinensis, the feed additive has importance on nutrient deposition and quality improvement of female crabs; the production cost of farmers can be reduced, the product value is improved, and technical support is provided for healthy development of the hairy crab industry.

Description

Technical Field

[0001] The invention relates to the technical field of aquatic feed, and in particular to a feed additive for promoting the development of muscles and gonads of Chinese mitten crabs and an application thereof. Background Art

[0002] Chinese mitten crab (Eriocheir sinensis), also known as hairy crab, is famous for its thick crab meat and rich crab roe. It is a characteristic species of China's aquaculture industry. The gonads (crab roe) of Chinese mitten crab have a unique flavor and taste, as well as rich nutrients, so they are loved by consumers. Compared with male crabs, female crabs have a higher gonad index, that is, they have more edible parts, and their ovaries are rich in nutrients such as highly unsaturated fatty acids, essential amino acids, phospholipids, vitamins and minerals, so they have higher edible value and economic value. In addition, the good ovarian development of female crabs not only affects the quality and market price, but also has a positive impact on their fertility and the health of their offspring. Therefore, the quality of the ovarian development of Chinese mitten crabs is closely related to the economic benefits of industrial development. The ovarian development of crabs needs to be strengthened through nutritional fortification. Although the proportion of compound feed used in the fattening of Chinese mitten crabs has gradually increased in recent years, farmers still use a large amount of fresh bait such as iced fish as the main source of feeding during the fattening stage of Chinese mitten crabs. However, due to the unstable source and quality of fresh frozen fish, its unreasonable use will cause the deterioration of the aquaculture water environment and increase the risk of pathogen invasion. Therefore, using high-quality compound feed to partially or completely replace fresh bait to improve the quality of female crabs has become a bottleneck and research hotspot in the development of the Chinese mitten crab industry.

[0003] Compared with fish and other higher animals, crustaceans cannot synthesize cholesterol on their own, so their demand for cholesterol is relatively limited. Therefore, cholesterol has a high nutritional value for crustaceans. Cholesterol, as a carrier for the transport of nutrients, especially lipids, and a precursor of hormones, has a good effect on improving the quality of crab gonads and muscles during fattening. However, it is still unclear which type of lipids cholesterol can best improve the quality of crabs during fattening.

[0004] Omega-3 highly unsaturated fatty acids (Ω-3 HUFA) are essential for the gonadal health and reproductive capacity of crustaceans. These fatty acids are not only important components of cell membranes, but also directly affect the function of the gonads, thereby affecting reproductive efficiency and the health of offspring. Despite this, it is still unclear how the interaction between cholesterol and Ω-3 HUFA jointly affects the gonadal development of Chinese mitten crabs and the quality improvement during the fattening stage.

[0005] Therefore, developing a fattening feed additive that can effectively promote the quality improvement of Chinese mitten crab, reduce the production cost of farmers, increase product value, and provide technical support for the healthy development of the hairy crab industry is a technical problem that the technicians of the present invention urgently need to solve. Summary of the invention

[0006] The present invention provides a feed additive for promoting the muscle and gonad development of Chinese mitten crab and application thereof, aiming to solve the problems existing in the above-mentioned background technology.

[0007] In order to achieve the above technical objectives, the present invention mainly adopts the following technical solutions:

[0008] The invention discloses a feed additive for promoting the development of muscles and gonads of Chinese mitten crabs. The feed additive comprises cholesterol and omega-3 highly unsaturated fatty acids.

[0009] In a preferred embodiment of the present invention, the following weights of feed additives are included in each kilogram of feed: 0.4-4.5 g of cholesterol and 3.5-4.5 g of omega-3 highly unsaturated fatty acids.

[0010] The invention also discloses an application of the feed additive mentioned above in preparing feed for promoting the muscle and gonad development of Chinese mitten crab.

[0011] In a preferred embodiment of the present invention, the feed additive increases the weight gain rate, gonad index and meat yield of Chinese mitten crab.

[0012] Furthermore, the feed additive improves the gonad index of Chinese mitten crab by increasing the yolk granule density, yolk cell volume and cell nucleus volume of female crabs.

[0013] In a preferred embodiment of the present invention, the feed additive improves the protein nutrient deposition capacity of the gonads and muscles of Chinese mitten crab.

[0014] In a preferred embodiment of the present invention, the feed additive improves the lipid transport capacity of Chinese mitten crab.

[0015] The invention also discloses a feed for promoting the development of muscles and gonads of Chinese mitten crabs, comprising the feed additive as described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The feed additive of the present invention can significantly improve the weight gain rate, gonad index and meat yield of female crabs in the fattening period by supplementing 4.022 g / kg of Ω-3 highly unsaturated fatty acids (Ω-3 HUFA) in feed containing 4.114 g / kg of cholesterol;

[0018] The feed additive of the present invention significantly improves the protein nutrition deposition capacity of gonads and muscles;

[0019] Using feed containing the feed additive of the present invention during the fattening period of Chinese mitten crab is important for the nutritional deposition and quality improvement of female crabs;

[0020] The feed additive of the present invention can reduce the production cost of farmers, improve the product value, and provide technical support for the healthy development of the hairy crab industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is the effect of the feed additive of the present invention on the gonad index, meat yield and weight gain rate of Chinese mitten crab;

[0022] Figure 2 This is a graph showing the effect of the feed additive of the present invention on crude protein and crude fat of Chinese mitten crab;

[0023] Figure 3 This is a graph showing the effect of the feed additive of the present invention on the yolk particle density in female Chinese mitten crabs;

[0024] Figure 4 This is a graph showing the effect of the feed additive of the present invention on the volume of yolk cells and the volume of nuclei in female Chinese mitten crabs;

[0025] Figure 5 This is a graph showing the effect of the feed additive of the present invention on the lipid transport capacity of Chinese mitten crab. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example

[0028] The test feed formula and its composition of this embodiment are shown in Table 1.

[0029] Among them, the vitamin premix includes one or more mixtures of vitamin A, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, vitamin D3, vitamin E, vitamin K3, niacin, D-calcium pantothenate, DL-calcium pantothenate, folic acid, D-biotin and choline chloride, aspartic acid, glutamic acid; the mineral premix includes one or more mixtures of compounds of sodium, potassium, calcium, magnesium, iron, copper, zinc, manganese, selenium, cobalt, molybdenum, chromium, phosphorus, chlorine and iodine.

[0030] Table 1 Nutritional composition of feed

[0031] Raw material (g / kg) Control group Experimental Group 1 Experimental Group 2 Experimental Group 3 Experimental Group 4 Experimental Group 5 Defatted fish meal 200 200 200 200 200 200 Casein 225 225 225 225 225 225 gelatin 75 75 75 75 75 75 Corn starch 180 180 180 180 180 180 Soybean Oil 100 99.6 96 96.7 96.3 92.7 Lecithin 20 20 20 20 20 20 Betaine 30 30 30 30 30 30 Calcium dihydrogen phosphate 10 10 10 10 10 10 Vitamin premix 60 60 60 60 60 60 Mineral premix 30 30 30 30 30 30 Choline chloride 5 5 5 5 5 5 BHT 1 1 1 1 1 1 Sodium Carboxymethyl Cellulose 20 20 20 20 20 20 Cholesterol (CHO) 0 0.4 4 0 0.4 4 Ω-3 HUFA 0 0 0 3.3 3.3 3.3 Microcrystalline Cellulose 44 44 44 44 44 44

[0032] Feed preparation method:

[0033] All raw materials were ground by a grinder and sieved through a 60-mesh sieve, and then the raw materials were fully mixed according to the formula. After the oily raw materials (including cholesterol, EPA and DHA) were fully mixed, deionized water (100mL / kg feed) was added and mixed thoroughly. Finally, the dough was made into granular feed with a diameter of 2 mm using a double-rod screw extruder (F-26, East China University of Science and Technology, Guangdong, China). The above feed was dried at room temperature and then further sieved into different particle sizes using 10, 14 and 16 mesh sieves. The experimental feeds were respectively packed in self-sealing bags and stored in a -20℃ refrigerator.

[0034] Test example

[0035] According to the above feed preparation process, 0 (control group), 0.04% cholesterol (experimental group 1), 0.4% cholesterol (experimental group 2), 0.33% Ω-3 HUFA (experimental group 3), 0.04% cholesterol + 0.33% HUFA (experimental group 4), 0.4% cholesterol + 0.33% Ω-3 HUFA (experimental group 5) were supplemented in the feed to prepare 6 groups of experimental semi-purified feeds with equal nitrogen and lipid content (Table 1). The cholesterol content of the 6 groups was detected to be 0.019, 0.413, 4.026, 0.013, 0.400, and 4.114 g / kg, respectively. The Ω-3 HUFA content of the 6 groups was 0.132, 0.125, 0.132, 3.884, 4.027, and 4.022 g / kg, respectively.

[0036] The breeding experiment was conducted at the Shanghai Fisheries Research Institute (Qingpu, Shanghai). Before the formal breeding experiment began, female crabs were temporarily raised in a 2000L cement pool to adapt to the breeding environment. During the temporary breeding period, the young crabs were fed with basic feed. Subsequently, 216 female crabs (initial average weight of 84.01±14.23g) were selected and randomly assigned to 36 breeding barrels (300L). Six young crabs were placed in each breeding barrel. Six tiles were placed at the bottom of the breeding barrel for shelter to reduce the phenomenon of cannibalism between different individuals during the breeding process. During the breeding experiment, the daily amount of experimental feed fed was 4% of the body weight of the young crabs, and the experiment lasted for 8 weeks. After 2 hours of feeding, the remaining feed and feces were discharged by siphoning. The daily water replacement volume was 30% of the volume of the breeding barrel, and sufficient aeration was performed to ensure the quality of the water environment during the feeding experiment. A natural light cycle was used during the experiment. The number of dead crabs and molting was recorded daily. The dissolved oxygen in the aquaculture water is always maintained above 7.0 mg / L; the pH value of the aquaculture water is maintained in the range of 7.5 to 8.5; the temperature of the aquaculture water is controlled between 22°C and 28°C; and the total ammonia nitrogen content in the aquaculture water is maintained below 0.05 mg / L.

[0037] After the breeding experiment, all experimental crabs were fasted for 24 hours before sampling, and then the number and weight of the remaining crabs in each breeding bucket were recorded to calculate the survival rate, weight gain rate and specific growth rate. Four crabs were randomly selected from each breeding bucket and stored in a -20℃ refrigerator for subsequent body nutrient composition analysis. Each crab was weighed, and the hepatopancreas was carefully removed and the weight was recorded for the calculation of the hepatopancreas index. Ten crabs were randomly selected from each bucket and placed on crushed ice for anesthesia. Then, hemolymph was carefully extracted from the base of the appendages with a 1mL syringe and collected in a 1.5mL centrifuge tube. After the hemolymph was placed in a 4℃ refrigerator overnight, the hemolymph in the centrifuge tube was fully mashed with a syringe needle until there was no obvious clot, and then centrifuged at 7000rpm and 4℃ for 10 minutes. Then the supernatant was carefully aspirated and divided into 0.2mL centrifuge tubes and stored in a -80℃ refrigerator. After extracting hemolymph, the crabs were dissected and the hepatopancreas was quickly removed with forceps, placed in a 1.5 mL cryotube, and stored in a −80 °C refrigerator for the determination of enzyme activity and molecular indices.

[0038] (1) To investigate the effects of feed additives on the gonad index, meat yield and weight gain rate of Chinese mitten crabs

[0039] Results Figure 1 ,Depend on Figure 1It can be concluded that adding cholesterol alone to traditional feed can improve the gonad index of Chinese mitten crab, and adding Ω-3 HUFA alone can improve the meat yield of Chinese mitten crab. In this experiment, when 4.114 g / Kg of cholesterol and 4.022 g / Kg of Ω-3 HUFA were added at the same time, the weight gain rate and meat yield of cholesterol Chinese mitten crab reached the highest level. Therefore, adding cholesterol and Ω-3 HUFA at the same time, that is, the feed additive of the present invention, can help improve the weight gain rate and meat yield of female crabs.

[0040] (2) Investigate the effects of feed additives on crude protein and crude fat in Chinese mitten crab

[0041] Results Figure 2 ,Depend on Figure 2 It can be concluded that during the fattening period of Chinese mitten crab, cholesterol and Ω-3 HUFA play an important role in the growth and development of gonads and muscles. When the cholesterol content was 4.114g / Kg and the Ω-3 HUFA was 4.022g / Kg, the crude protein content of gonads and muscles increased significantly. When cholesterol and Ω-3 HUFA were added at the same time, as the cholesterol content increased, the crude fat content of the hepatopancreas gradually decreased, while the crude fat content of the gonads gradually increased. Therefore, cholesterol and Ω-3 HUFA play an important role in fat transport capacity during the fattening period.

[0042] (3) Investigate the effect of feed additives on the yolk particle density of female Chinese mitten crabs

[0043] Results Figure 3 ,Depend on Figure 3 It can be concluded that the ovaries of female crabs in the group treated with cholesterol in the traditional feed were filled with yolk granules, and the density of yolk granules was greater after HUFA supplementation.

[0044] (4) To investigate the effects of feed additives on the volume of yolk cells and nuclei in female Chinese mitten crabs

[0045] Results Figure 4 ,Depend on Figure 4 It can be concluded that adding 4g / Kg of cholesterol alone can significantly increase the volume of yolk cells and nucleus; adding 4g / Kg of Ω-3 HUFA alone can also significantly increase the volume of yolk cells; when 4.114g / Kg of cholesterol and 4.022g / Kg of Ω-3 HUFA are added at the same time, the volume of yolk cells increases most significantly. Therefore, adding cholesterol and Ω-3 HUFA to the feed at the same time can help increase the volume of yolk cells.

[0046] (5) Investigate the effects of feed additives on lipid transport capacity of Chinese mitten crab

[0047] Results Figure 5 ,Depend on Figure 5It can be concluded that the addition of cholesterol alone can significantly increase the levels of TCHO and LDL-C in the hepatopancreas and serum.

[0048] In the description of this specification, the description with reference to the term "specific embodiment" or the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A feed additive for promoting the development of muscles and gonads of Chinese mitten crab, characterized in that: The feed additives include cholesterol and omega-3 highly unsaturated fatty acids.

2. The feed additive according to claim 1, characterized in that Each kilogram of feed includes the following weights of feed additives: 0.4-4.5g of cholesterol and 3.5-4.5g of omega-3 highly unsaturated fatty acids.

3. Use of the feed additive as described in any one of claims 1-2 in preparing a feed for promoting the muscle and gonad development of Chinese mitten crab.

4. The use according to claim 3, characterized in that: The feed additive improves the weight gain rate, gonad index and meat yield of Chinese mitten crab.

5. The use according to claim 4, characterized in that: The feed additive improves the gonad index of Chinese mitten crab by increasing the yolk particle density, yolk cell volume and cell nucleus volume of female crab.

6. The use according to claim 3, characterized in that: The feed additive improves the protein nutrient deposition capacity of the gonads and muscles of the Chinese mitten crab.

7. The use according to claim 3, characterized in that: The feed additive improves the lipid transport capacity of Chinese mitten crab.

8. A feed for promoting muscle and gonad development of Chinese mitten crab, characterized in that: The feed additive comprises the feed additive as described in any one of claims 1 to 2.

Images