Leiocassis longirostris juvenile fish pond feed transferring method

Abstract

The invention provides a young leiocassis longirostris pond feed transferring method. The young leiocassis longirostris pond feed transferring method comprises the steps of pond preparation, net enclosure repairing, aerator arrangement, incandescent lamp pole erecting, feed transferring basket manufacturing and fry stocking. The material transferring process comprises the steps of feeding plankton, removing plankton, processing artificial feed and controlling the transferring time. By adopting the method for transferring the young leiocassis longirostris, the leiocassis longirostris fries which are successfully transferred can be cultivated in batches in a planned manner so as to meet the requirements of users, and excessive loss of the leiocassis longirostris fries in the process of transferring the leiocassis longirostris fries is avoided. Experimental results show that the conversion rate of the whole pool is about 60% and can be increased by more than 20% compared with the conversion rate in the prior art.

Description

Technical Field

[0001] The present invention belongs to the technical field of freshwater fish farming, and relates to a method for transferring feed in artificial ponds of freshwater fish, and specifically relates to a method for transferring feed of juvenile Leiocassis longirostris in ponds. Background Art

[0002] Leiocassis longirostris, commonly known as "Jiangtuan", generally reaches 1.0 - 2.0 kg after a growth cycle of 2 - 3 years. It is a medium-sized fish with delicate meat, delicious taste, rich nutrition, and few intermuscular spines, and is a precious variety among edible freshwater fish. In recent years, the breeding and sales of Leiocassis longirostris have been continuously increasing, with good market prospects.

[0003] A sufficient supply of fish fry is a key factor for the large-scale industrialized farming of Leiocassis longirostris. The process of converting juvenile fish from feeding on natural bait to swallowing artificial compound feed at the fry stage is a key technology to improve the survival rate of juvenile Leiocassis longirostris and accelerate growth. Currently, the survival rate of juvenile Leiocassis longirostris during the feed transfer process in ponds is less than 50%, which is not conducive to the large-scale cultivation of Leiocassis longirostris fry and also affects the economic benefits of Leiocassis longirostris farming. Therefore, improving the method for transferring feed of juvenile Leiocassis longirostris, increasing the survival rate and the utilization rate of artificial compound feed during the feed transfer process, and promoting the rapid growth of juvenile fish, and then implementing industrial expansion, are of great significance. Summary of the Invention

[0004] Based on the above problems, the present invention aims at the deficiencies of the existing technology and provides a method for transferring feed of juvenile Leiocassis longirostris, which can batch cultivate successfully feed-transferred Leiocassis longirostris fry in a planned manner to meet the needs of users, avoid excessive losses of Leiocassis longirostris fry during the feed transfer process, and can also save manpower, material resources and financial resources.

[0005] To achieve the above object, the technical solutions adopted by the present invention are outlined as follows: Based on the feeding characteristics of juvenile Leiocassis longirostris growth agent, in May, a net enclosure is set at a corner of the pond inlet, and an aerator, an incandescent lamp and a feeding basket are installed inside the net enclosure; then after disinfecting the whole pond, juvenile Leiocassis longirostris fry 3 days after hatching are put into the net enclosure for domestication. During the domestication process, plankton is put in the early stage when the fry enter the pond, and the plankton in the water body is killed in the middle stage to cut off the source of natural bait for Leiocassis longirostris fry, and the compound feed for Leiocassis longirostris fry is changed to be stirred into a cake shape. After 3 days of feeding domestication, more than 70% of the juvenile Leiocassis longirostris can feed on artificial compound feed.

[0006] Based on this, the specific technical solutions adopted by the present invention are as follows:

[0007] The method for transferring feed of juvenile Leiocassis longirostris in ponds provided by the present invention includes the following steps:

[0008] A. Preparation before feed transfer

[0009] Set up a triangular net enclosure at a corner of the pond near the water inlet, and install an aerator, multiple air injection nozzles, spotlight, and feeding basket inside the net enclosure, as follows:

[0010] (1) Net enclosure: Enclose a triangular water surface at a corner of the pond near the water inlet with 40-mesh polyethylene netting. This triangular water surface accounts for about 2.5% of the pond water surface. The netting is fixed to wooden stakes with a 1-meter spacing. The normal water level is 60 cm, and the top of the netting is 30 cm above the water level;

[0011] (2) Roots blower aerator: Install one in the water body for every 50 m 2 Install one air injection nozzle every 5 m 2 inside the net enclosure. Prop up the air injection nozzle with a bamboo pole, with its position 10 cm above the bottom mud to ensure that the water body is not turbid;

[0012] (3) Spotlight: Select 60-watt incandescent lamps. Install 2 lamps in the water body for every 50 m 2 and use a 40-cm diameter lamp shade to focus the light;

[0013] (4) Feeding basket: Set the density to one basket every 10 m 2 inside the net enclosure. The basket is a circular one with a diameter of 40 cm and pores the size of a one-yuan coin (25 - 30 mm) to ensure that fry can freely enter and exit without obstruction all around. Lay a layer of 10-mesh polyethylene hepta-twisted netting at the bottom of the basket.

[0014] B. Transshipment method

[0015] (1) Pond preparation: Drain the pond water completely about 10 days before fry stocking in May. Disinfect the whole pond with high-purity calcium oxide (50 kg / mu). After 3 days, inject new water to a water level of 60 cm. Test the water and stock fry 5 - 7 days after water injection;

[0016] (2) Transfer the catfish fry 3 days after hatching into the outdoor triangular net enclosure for cultivation. The stocking density is 4000 - 6000 tails / m 2 (preferably 4000 - 5000 tails / m 2 ), turn on the aerator 24 hours a day, and feed plankton (cladoceran larvae and adults). Turn on the spotlight at night to gather plankton;

[0017] (3) When the total length of the catfish fry reaches 2.5 cm, spray a fungicide (90% crystal trichlorfon at 0.4 ppm) over the whole pond to kill the plankton in the water body and cut off the natural food source for the catfish fry;

[0018] After killing the plankton, the formulated feed for Leiocassis longirostris fingerlings with a crude protein content of 42% is mixed with water and stirred into a cake shape, which is placed in the feeding basket. A plurality of the feeding baskets are placed at a water depth of 30 cm under the light. According to the feeding situation of the fry, the feed is replaced every certain period of time to ensure the freshness and palatability of the feed. The feeding domestication is carried out for at least 72 hours by using this method.

[0019] The beneficial guarantees and effects of the present invention are as follows:

[0020] By using the method for transferring feed of juvenile Leiocassis longirostris of the present invention, it is possible to batch cultivate Leiocassis longirostris fry with successful feed transfer in a planned manner to meet the needs of users, and avoid excessive losses of Leiocassis longirostris fry during the feed transfer process. The experimental results show that when the stocking density is 6000 tails / m 2 , the conversion rate is about 60%; when the stocking density is reduced to 4000 tails / m 2 , the conversion rate is increased to about 70%, which can be increased by more than 20% compared with the conversion rate of the prior art.

[0021] In terms of equipment investment, only a polyethylene plastic net enclosure, wooden stakes, nylon ropes, a Roots blower aerator, a 60-watt incandescent lamp, and a feeding basket are required, which are all common equipment in the aquaculture field. The investment is low or even no additional investment is required, saving manpower, material resources and financial resources. Specific Embodiments

[0022] The following describes the implementation of the present invention in detail in conjunction with the embodiments of the present invention. The following embodiments are implemented on the premise of the technical solution of the present invention, and the detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0023] The experimental methods in the following embodiments are all conventional methods unless otherwise specified, and are carried out according to the technologies or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified.

[0024] Example 1

[0025] In this example, the pond transfer of juvenile Leiocassis longirostris is carried out in a fry breeding pond with a water surface area of 3 mu, including the following steps:

[0026] (1) Preliminary preparation work before fry stocking

[0027] a. Pond preparation: About 10 days before fry stocking in May, the pond water is drained completely, and a triangular net enclosure is made at one corner of the water inlet. The pond is disinfected with high-purity calcium oxide (50 kg / mu) (sprayed all over the pond).

[0028] b. Net enclosure repair: Use 40-mesh polyethylene netting (1-meter height) to enclose a triangular water surface of about 50 m 2 at a corner of the pond near the water inlet. The triangular water surface accounts for about 2.5% of the pond water surface. Both the upper and lower steel parts of the net are wrapped with nylon ropes as thick as a finger. The netting is fixed to wooden stakes with a 1-meter spacing. The normal water level is 60 cm, and the top of the netting is 30 cm above the water level.

[0029] c. Aerator setting: Set up one Roots blower aerator, and lay out oxygen pipes with air injection heads inside the net enclosure. Place one air injection head every 5 ㎡. The air injection head can be supported by a bamboo pole, 10 cm above the bottom mud, to ensure that the water body is not turbid.

[0030] d. Incandescent lamp pole erection: Erect 2 incandescent lamp poles and 2 incandescent lamps (60 watts). Use a lampshade with a 40-cm diameter to focus the light. The incandescent lamps are 50 cm above the water surface.

[0031] e. Water injection and water testing: Inject new water 3 days after disinfection with high-purity calcium oxide. Test the water 7 days after water injection and then release fry.

[0032] (2) Fry stocking

[0033] a. Transfer the Leiocassis longirostris fry 3 days after hatching into the outdoor net enclosure for cultivation (release 200,000 fry into the 50 m 2 triangular net enclosure water surface). Turn on the aerator 24 hours a day, and feed plankton (juvenile and adult cladocerans). Turn on the incandescent lamps at night to gather plankton.

[0034] b. When the total length of the Leiocassis longirostris fry reaches 2.5 cm, spray 0.4 ppm of crystal trichlorfon (90%) all over the pond (including inside the net enclosure) to kill the plankton in the water body and cut off the natural food source of the Leiocassis longirostris fry.

[0035] c. After killing the plankton, mix the Leiocassis longirostris fingerling compound feed with a crude protein content of 42% with water and stir it into a cake shape. Place it in a feeding basket, and place the feeding basket at a water depth of 30 cm under the light. Place one feeding basket every 10 m 2 . According to the feeding situation of the fry, change the feed every 4 hours to ensure the freshness and palatability of the feed. The fry feed more concentratedly at night, and the feeding amount of the feed can be adjusted according to the situation.

[0036] d. After 72 hours of feeding domestication, more than 71% of the Leiocassis longirostris fry can feed on artificial compound feed.

[0037] Example 2

[0038] In this Example 2, the only difference from Example 1 is that the 50 m 2In a triangular purse seine with a size of 50m, 250,000 fry of Leiocassis longirostris were released into the water surface, and the rest was the same as in Example 1. After 72 hours of feeding domestication, more than 70% of the Leiocassis longirostris fry could feed on artificial compound feed.

[0039] Example 3

[0040] In this Example 3, the only difference from Example 1 is that 2 In a triangular purse seine with a size of 50m, 300,000 fry of Leiocassis longirostris were released into the water surface, and the rest was the same as in Example 1. After 72 hours of feeding domestication, more than 60% of the Leiocassis longirostris fry could feed on artificial compound feed.

[0041] The parts not described in this invention are the same as the prior art or are implemented using the prior art. The applicant declares that this invention uses the above examples to illustrate the detailed method of this invention, but this invention is not limited to the above detailed method, that is, it does not mean that this invention must rely on the above detailed method to be implemented. Those skilled in the art should understand that any improvement of this invention, the equivalent substitution of each raw material of this invention's product and the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of this invention.

Claims

1. A method for transferring feed in a pond for juvenile Leiocassis longirostris, characterized in that, It includes the following steps: A. Preparation before material transfer In about 10 days before fry stocking in May, drain the pond water completely. Set up a triangular net enclosure at a corner of the pond near the water inlet, and install an aerator, multiple air diffusers, a spotlight, and a feeding basket inside the net enclosure; B. Method of material transfer (1) Pond preparation: Clean the whole pond with high-purity calcium oxide. Inject new water 3 days later. After 5 - 7 days of water injection, test the water and stock fry; (2)The catfish fry 3 days after hatching and emergence are transferred to an outdoor triangular enclosure for cultivation, with a stocking density of 4000 - 6000 tails / m 2 , and the aerator is turned on 24 hours a day, and plankton is fed. A spotlight is turned on at night to gather plankton; (3) When the total length of Leiocassis longirostris larvae reaches 2.5 cm, sprinkle a fungicide all over the pond to kill plankton in the water body and cut off the natural food source of Leiocassis longirostris fry; (4) After killing the plankton, mix the Leiocassis longirostris fingerling compound feed with a crude protein content of 42% and water to form a cake shape, and place it in the feeding basket. There are multiple feeding baskets placed at a water depth of 30 cm under the light. According to the feeding situation of the fry, replace the feed at regular intervals to ensure the freshness and palatability of the feed; Use this method for at least 72 hours of feeding domestication.

2. The method for transferring materials in the Leiocassis longirostris fry pond according to claim 1, characterized in that: Among them, The water surface area of the triangular net enclosure accounts for 2.5% of the pond water surface. The net enclosure is made of 40-mesh polyethylene net cloth, which is fixed on wooden stakes with a stake spacing of 1 meter. The normal water level is 60 cm, and the top of the netting is 30 cm higher than the water level.

3. The method for transferring materials in the Leiocassis longirostris fry pond according to claim 1, characterized in that: Among them, The aerator is a Roots blower aerator, with one unit installed per 50 m 2 of water body, and one aeration head placed per 5 m 2 inside the net enclosure; the position of the aeration head is 10 cm higher than the bottom mud. The spotlight is a 60-watt incandescent lamp, one is set every 25m 2 in the water body, 50 cm above the water surface, and a 40-cm diameter lampshade is used for spotlighting.

4. The method for transferring materials in the Leiocassis longirostris fry pond according to claim 1, characterized in that: Among them, The setting density of the feeding basket is one per 10 m 2 and the feeding basket is a circular basket with a diameter of 40 cm, with pores of 25 - 30 mm to ensure that fry around can freely enter and exit without obstacles; a layer of 10 - mesh polyethylene heptuple twill wire cloth is laid on the bottom of the basket.

5. The method for transferring materials in the Leiocassis longirostris fry pond according to claim 1, characterized in that: Among them, In step (1), use high-purity calcium oxide to sprinkle the whole pond at 50 kg / mu for pond cleaning. Inject new water 3 days later, and the water level is 60 cm.

6. The method for transferring materials in the Leiocassis longirostris fry pond according to claim 1, characterized in that: Among them, In step (2), the stocking density of the catfish seedlings is 4000 - 5000 tails / m 2 , The plankton is selected from the larvae and adults of Cladocera.

7. The method for transferring materials in the Leiocassis longirostris fry pond according to claim 1, characterized in that: Among them, In step (3), the fungicide is selected from 0.4 ppm of 90% crystalline trichlorfon and sprinkled all over the pond.