Aquaculture technology? what do you need to pay attention to when raising crayfish in rural areas in the early spring? How to breed without losing money

After the beginning of spring next year, crayfish that have lived in caves for a winter will come out in large numbers to look for food in the pond. With the gradual recovery of water temperature and the increase of nutrition of parent shrimp after feeding, the larvae have begun to live freely in the pond, and the culture density in the pond has also increased rapidly. Therefore, the management should be strengthened in the process of crayfish seedling cultivation in spring to ensure a good start of crayfish culture in the whole year. Now the relevant techniques of collation and editing are introduced as follows, which can only be used as a reference for crayfish farmers.

First, choose good water

Pond conditions choose places close to water sources, sufficient water quantity, fresh water quality, no pollution sources, quiet environment, matching electric power and convenient transportation. The pond is rectangular, east-west, with large wind area and long light time. In order to facilitate management, the area is generally 3300 to 6700 square meters (5 mu), the depth of the pool is 1.2 to 1.5 meters, the ratio of pool to slope is 1 ∶ 3, the soil quality is clay, and the bottom of the pond is flat. There are two small mud ridges in the pond (the length of the pool is 3000mm, the width is about 1m, it is 5cm above the water surface, and the two ends are not connected with the ridge, so it is convenient for the production boat to pass through), which adds a hole or habitat for the crayfish. The pond is surrounded by 30 cm smooth calcium plastic board hanging on the upper eaves, the outside is fixed by wooden piles, and the PVC mesh with a height of 50 cm is used as anti-escape facilities. The pond has an independent intake and drainage system (the inlet and outlet is sealed with a filter), and is equipped with mechanical and electrical equipment such as oxygen enrichment and pumping.

Second, clear the pond and disinfect

Pond cleaning disinfection can effectively kill enemy organisms in the pond (catfish, Loach, snakehead, snake, rat, etc.), wild miscellaneous fish (common carp, crucian carp, etc.), and pathogens. Quicklime and bleach can be used, which is economical, economical and safe. The specific operation methods are as follows: 1. Sterilized with quicklime. Dry disinfection: 70 kilograms of quicklime per mu, sprinkle the whole pool with chemical water, and then hug with nail rake if possible, after a week in the pond, inject new water; disinfect with water: the surface of each mu is calculated according to the water depth of 1 meter, and 130 kilograms of quicklime is dissolved in the water. Sprinkle evenly in the whole pool. two。 Disinfect with bleach. After the bleach containing 30% available chlorine was completely dissolved, the whole pool was evenly sprinkled with a dosage of 25 kg per mu.

3. Stocking of seedlings

The stocking specification is 2cm, the density is 6000cm / mu, and the time is from March to April. Shrimp fry should be released in the morning and evening in sunny days, and the specifications of shrimp fry in the same pond and batch should be the same. In order to make full use of water space and bait resources and increase pond productivity, each mu can be stocked with 100g ∕ tail silver carp and bighead carp. Before stocking, the seedlings need to be washed and disinfected with 3%-4% salt solution for 5-10 minutes to kill bacteria and parasites on the body surface.

Fourth, bait feeding

The juvenile shrimp culture stage is mainly fed with formula feed with a crude protein content of 36% to 40%, and the daily feeding amount is 3% to 5% of the total body weight of shrimp in the pond. In addition, it is necessary to properly feed some fresh miscellaneous fish to meet the nutritional needs for the development and growth of young shrimps; the adult shrimp culture stage is mainly fed with formula feed with a crude protein content of 30% to 35%, and the daily feeding amount is 4% to 5% of the total body weight of pond shrimp. In addition, it is necessary to properly feed partially cooked corn, soaked germinated wheat and fresh miscellaneous fish to improve the specification of adult shrimp and increase the yield of culture. In the whole process of crayfish culture, the bait was fed twice a day, once before sunrise in the morning and once after sunset in the evening, mainly in the evening, accounting for 60% and 70% of the daily feed. Put the bait on the pond bank or shoal to let the crayfish develop the habit of fixed-point feeding. The specific feeding amount should be scientifically controlled according to the season, weather, water quality, water temperature and crayfish molting and feeding. Generally speaking, it is appropriate to finish eating 2 hours after feeding.

V. Daily management

The focus of daily management of shrimp ponds is to patrol the ponds. The focus of the pond patrol is to observe the activities of shrimp, changes in water quality and weather conditions.

If the crayfish rest during the day, activity at night, and eat normally, it means that the shrimp is healthy and the pond environment is good. If shrimp come out during the day, check for disease. If the shrimp body is disease-free, and the food intake suddenly decreases, and a large number of surface water surface during the day, indicating that the water body is lack of oxygen, it is necessary to change water or increase oxygen in time.

When looking at the water, in addition to mastering the changes of water color and adjusting the water quality in time, we should also timely trim the leaking embankment and salvage the uneaten bait in time.