CATDOLL : CATDOLL: What aspects should be paid attention to in the breeding and management of shrimp in cages?

The management of cage-raised freshwater shrimp is a highly technical job. The following four tasks should be focused on:

(1) Stocking of shrimp fry and shrimp seeds

Generally, two batches of shrimp can be raised in cage culture in a year. The first batch of shrimp is released in late March, mainly large-sized shrimp species that have overwintered, with a body length of 2.5-3 cm and a weight of 0.5-1 gram. 100-150 shrimp can be placed per square meter of cage. After more than two months of careful feeding and management, they are caught and put on the market from late June to early July, or sold as artificially bred prawns. The second batch of shrimp begins to be released in late July, mainly shrimp species cultivated that year, with a body length of 1.5-2.5 cm and a weight of 0.2-0.5 grams. 150-200 shrimp can be placed per square meter of cage. The stocking density of shrimp species can also be adjusted according to local conditions and time according to water conditions, bait sources, feeding and management techniques, and the size of cage area, so as to make full and rational use of water resources and improve the yield and benefits of cage culture of shrimp. Units with conditions, especially those with good shrimp seedlings and shrimp species, can raise three batches of shrimp a year. (2) Scientific baiting

Cage culture of freshwater shrimp, due to its fast water exchange and good water quality, the quality and quantity of the bait fed become the key to shrimp farming. In terms of feeding bait, the first thing is to control the quality of the bait. Cage culture of freshwater shrimp, the crude protein content of the compound feed is required to be about 35%. At the same time, pay attention to the use of a series of compound feeds to improve the palatability of the bait. It is also necessary to feed some animal baits processed into fish paste with snails, clams, small fish and shrimps. Decayed and spoiled baits cannot be used, and compound feeds with low crude protein content should not be used. Second, it is necessary to scientifically master the daily feeding amount. The daily feeding amount of compound feed can be fed at 5% to 8% of the body weight of the shrimp in the box. When the weather is fine and the freshwater shrimp eats vigorously, it can be fed more appropriately, and less can be fed on rainy days; less should be fed when a large number of freshwater shrimp molt, and more should be fed after molting. Third, the correct feeding method should be adopted. When breeding freshwater shrimp in cages, the bait should be fed in small amounts, multiple times, at regular times, with fixed quality and quantity. Feeding should be done 2 to 4 times a day, mainly at night, which should account for 70% of the daily feeding amount. The daily feeding amount should be adjusted in time according to the freshwater shrimp's feeding activities and weather changes to prevent the loss and waste of bait. (3) Strengthen daily management

The management of cage-cultured shrimp mainly includes "four diligences" and "four preventions". The four diligences are: first, frequent cage inspections, check the cages 3 to 4 times a day, check the activity and feeding of the shrimp, check the water exchange, check whether the cages are damaged, and check the growth of the shrimp; second, wash the cages frequently. It is easy for algae and dirt to adhere to the cages in the water, blocking the mesh and affecting the smooth exchange of water inside and outside the cages. Therefore, the cages should be washed frequently to remove the remaining bait and shrimp excrement in the cages and keep the cages clean and hygienic; third, frequent maintenance of facilities, regular inspection of the integrity of the cages, and timely repair or replacement of holes to ensure that the cages are intact; fourth, frequent record keeping. The four preventions are: first, prevention of enemies; second, prevention of escape; third, prevention of floods; and fourth, prevention of diseases. (4) Do a good job in setting up artificial shrimp nests in cages

Freshwater shrimps need attachments for habitat, feeding and molting. There are two ways to set up artificial shrimp nests in cages. One is to place aquatic plants, mainly Hydrilla verticillata, Waterweed and Duckweed, which are required to occupy 1/3 of the cage area; the other is to hang mesh in the cage, woven with polyethylene, with a mesh size of 9, a width of 50 cm, and a length equal to the short side of the cage. The mesh is arranged parallel to the short side of the cage, and one piece is hung every 1 meter. The two ends of the mesh are connected to the long side of the cage. The upper side of the mesh is 5 cm above the water surface, and the lower side is suspended to increase the attachment area of ​​the cage to prevent the freshwater shrimps from being overly concentrated. The cage with the hanging mesh should also be combined with aquatic plants.

The management of cage-raised freshwater shrimp is a highly technical job. The following four tasks should be focused on:

(1) Stocking of shrimp fry and shrimp seedlings Cage-cultured freshwater shrimp can generally be raised twice a year. The first batch of shrimp is released in late March, mainly large-sized shrimp seedlings that have overwintered. High-quality shrimp seedlings with a body length of 2.5 to 3 cm and a weight of 0.5 to 1 gram can be placed in 100 to 150 shrimps per square meter of cage. After more than two months of careful feeding and management, the shrimps are harvested and put on the market in late June or early July, or sold as artificially bred prawns. The second batch of shrimp is released in late July, mainly shrimp seedlings cultivated that year. Shrimp seedlings with a body length of 1.5 to 2.5 cm and a weight of 0.2 to 0.5 g can be placed in 150 to 200 shrimps per square meter of cage. The stocking density of shrimp seedlings can also be adjusted according to local conditions and time, based on water conditions, bait sources, feeding and management techniques, and the size of cages, so as to make full and rational use of water resources and improve the yield and benefits of cage-cultured freshwater shrimp. Units with the conditions, especially those with better supporting conditions for shrimp fry and shrimp seeds, can raise three batches of shrimp a year.

(2) Scientific feeding. Cage-cultured shrimps have fast water exchange and good water quality, so the quality and quantity of the feed are the key to shrimp farming. In terms of feeding, the first thing to do is to control the quality of the feed. Cage-cultured shrimps require a crude protein content of about 35%. At the same time, pay attention to the use of a series of compound feeds to improve the palatability of the feed. It is also necessary to feed some animal feed made from snails, clams, small fish and shrimps into fish paste. Decayed and spoiled feeds cannot be used, and compound feeds with low crude protein content should not be used. Second, the daily feeding amount must be scientifically controlled. The daily feeding amount of compound feed can be 5% to 8% of the body weight of the shrimp in the cage. When the weather is fine and the shrimps eat vigorously, you can feed more appropriately, and less on rainy days; when a large number of shrimps are molting, you should feed less, and after molting, you should feed more. Third, you must adopt the correct feeding method. For cage culture of freshwater shrimp, the bait should be fed in small amounts, multiple times, at regular times, with fixed quality and quantity. Feeding should be done 2 to 4 times a day, mainly at night, which should account for 70% of the daily feeding amount. The daily feeding amount should be adjusted in time according to the freshwater shrimp's feeding activities and weather changes to prevent the loss and waste of bait.

(3) Strengthening daily management The management of cage-cultured freshwater shrimp mainly includes "four diligences" and "four preventions". The four diligences are: first, frequent cage inspections. Check the cages 3 to 4 times a day to check the freshwater shrimp's activities and feeding conditions, water exchange conditions, whether the cages are damaged, and the growth conditions of the freshwater shrimp; second, frequent cleaning of the cages. Cages in the water are prone to a lot of algae and dirt, which block the mesh and affect the smooth exchange of water inside and outside the cages. Therefore, cages should be cleaned frequently to remove the remaining bait and shrimp excrement in the cages and keep the cages clean and hygienic; third, frequent maintenance of facilities. Frequently check the integrity of the cages. If holes are found, they should be repaired or replaced in time to ensure that the cages are intact; fourth, frequent record keeping. The four preventions are: first, prevention of enemies; second, prevention of escape; third, flood prevention; and fourth, disease prevention.

(4) Make good use of artificial shrimp nests in the cages. Freshwater shrimps need attachments for habitat, feeding and molting. There are two ways to set up artificial shrimp nests in cages. One is to place aquatic plants, mainly Hydrilla verticillata, Waterweed and Duckweed, which should occupy 1/3 of the cage area. The other is to hang mesh in the cage, woven with polyethylene, with a mesh size of 9, a width of 50 cm and a length equal to the short side of the cage. The mesh is arranged parallel to the short side of the cage, and one piece is hung every 1 meter. The two ends of the mesh are connected to the long side of the cage. The upper side of the mesh is 5 cm above the water surface, and the lower side is suspended in the air to increase the attachment area of ​​the cage to prevent the freshwater shrimps from being overly concentrated. The cage with the mesh hanging should also be combined with aquatic plants.

This article is from: China Agricultural Press "Animal Welfare and Meat Production"