Five key points for farming freshwater crayfish in rice paddies after the start of winter

We all know that many creatures generally have the habit of hibernating in winter, just like us humans: in winter their activity level drops a lot, so people's resistance is also much weaker in winter, and in winter the crayfish's activity level likewise drops a lot.

Five key points for farming freshwater crayfish in rice paddies after the start of winter

As the temperature drops, friends who farm crayfish in rice paddies should pay attention to the following points in winter:

1. Reinforcement: after the crayfish fry arrive in a new environment, they will burrow and build holes everywhere. If the field ridge is too narrow, it is easy for the crayfish to “go through the wall and dig holes”, causing the fry to escape and the paddy field to leak water. When the water level drops, the other crayfish will again burrow and build holes or escape. 2. Hole building: on both sides of the field ditch, below the field surface by 15 cm, use a wooden stick or shovel to make some artificial holes in the mud; the angle of the holes should be small, as close as possible to “parallel” with the field. Once the crayfish have “ready-made” holes, they will not “tire themselves out”, which saves their physical energy and reduces damage to the field ridge. 3. Straw covering: appropriately scatter some crop straw (such as rice straw) in the paddy field; first, it has a warming effect; second, it serves as food; because after the straw and rice straw rot, they are very good feed for crayfish. 4. Feeding: at the right time and in the right amount, add nutrients for the crayfish, such as wheat bran and corn grits; mix the feed with water, knead it into small balls and put them into the field. With nutrition, it is easier for the crayfish to grow and reproduce. 5. Water retention: keep the water surface 20 cm above the field surface, and do not let it rise and fall from time to time. Changes in water level can easily cause the crayfish to dig holes repeatedly, move their holes, or consume physical energy, die, or damage the field ridge, and so on.

Points to note in crayfish farming  

First, create a good growing environment for the crayfish. Because crayfish love to dig holes, generally the depth of the holes is 50-80 cm, and some holes exceed 1 m in depth. To avoid them digging holes and escaping, the ridge around the farming water body should be more than 1.5 m wide, and around the ridge a 0.5 m high anti-escape net, or an anti-escape wall or anti-escape board with a smooth inner wall, should be set up; the surrounding net must also be buried 2 m deep to prevent the crayfish from escaping. At the same time, the pond should simulate the crayfish's ecological environment under natural conditions; plant 10-15% aquatic plants and hiding objects along the shallow edges of the pond, creating an environment for the crayfish to inhabit and molt, and reducing mutual killing.

Second, feed reasonably. Because crayfish will kill each other when hungry or when food is insufficient, the feeding amount must be sufficient. Also, crayfish feed is both animal and plant feed. Plant feed includes wheat, aquatic plants, rapeseed cake, etc.; animal feed includes miscellaneous fish, miscellaneous meat, and livestock offal, etc. Usually, determine the feeding time, feeding amount and feeding method according to the crayfish's habit of hiding by day and coming out at night, and according to the density of shrimp in the pond.  

Finally, do a good job of scientific harvesting. Under suitable temperature and sufficient feed, young shrimp generally reach commercial size in 60-90 days. Release the fry in March, start rotational harvesting around June, selling the large ones and keeping the small ones.   

Base construction for crayfish farming  

1. The site selection of a crayfish farming base must fully consider the surrounding environment, such as whether water sources are abundant, the source of bait, and whether transportation and power supply are convenient, all of which need specific consideration. Among these, the investigation of water quality is very important, and the pH value of the water must be controlled at around 6-8.  

2. Disinfection work for the crayfish farming base can generally be done with quicklime or bleaching powder; simply crush the quicklime and spread it evenly into the pond water, then on the next day use an iron rake to stir the pond bottom so that the lime and silt can fully mix. Of course, there are still many specific disinfection methods, and farmers can choose for themselves.  

3. Building a crayfish farming base requires professional technicians. For a crayfish farming base, professional technicians are very important; for example, broodstock pond preparation, parent shrimp selection, parent shrimp release, parent shrimp cultivation, water quality management, fertilization and hatching, shrimp fry cultivation and so on all require scientific and reasonable technical support, so as to ensure the healthy growth of the crayfish.

Feed formulas for crayfish farming  

For juvenile shrimp feed, the crude protein content is 37.4%, and the ratio of various raw materials is: Peruvian fishmeal 20%, fermented blood meal 13%, soybean cake 22%, cottonseed cake 15%, wheat middlings 11%, cornmeal 9.6%, bone meal 3%, yeast powder 2%, multivitamin premix 1.3%, molting hormone 0.1%, starch 3%.  

For adult shrimp feed, the crude protein content is 30.1%, and the ratio is: Peruvian fishmeal 5%, fermented blood meal 10%, soybean cake 30%, cottonseed cake 10%, wheat middlings 25%, cornmeal 10%, bone meal 5%, yeast powder 2%, multivitamin premix 1.3%, molting hormone 0.1%, starch 1.6%.  

Among these, the soybean cake, cottonseed cake, wheat middlings, corn, etc. should be crushed again before premixing, and after pelletizing they should be dried for more than 2d to prevent the feed from spoiling. In the 2 feed formulas, an additional aquatic feed binder amounting to 0.6% of the total is added to increase the feed's water resistance time.  

Although farming crayfish in winter is rather troublesome, as long as you master certain techniques and methods it is still fairly easy; farmers should farm crayfish reasonably according to changes in the weather.