What should be noted in the fattening of river crab farming
Currently, river crabs are in the process of shedding their last shell and entering the fattening and rapid weight-gain stage. At this time, the following points should be noted in feeding management:
1. Pay attention to water quality issues
At this stage, although the water temperature has already dropped, the stock density of river crabs, fish, shrimp, etc. in the pond is at a relatively high level, and the amount of dissolved oxygen they consume surges. In addition, river crabs in the shell-shedding period have a far higher demand for dissolved oxygen than during the normal growth period, so the pond water needs to maintain sufficient dissolved oxygen. At the same time, the aquatic plants in the pond have entered the aging stage, and broken stems and rotten grass appear from time to time, which will also putrefy the water quality. Therefore, at this time, even more attention should be paid to water quality issues, promptly cutting away part of the aquatic plants and removing the residual grass to effectively increase the water body space.
2. Strengthen feed feeding
Shell shedding, fattening and rapid weight gain in river crabs all require the supplementation of large amounts of nutrients, and the feeding of animal-based nutrients is especially important. The feeding of small trash fish or marine fish should be increased, the protein content of compound feed should also be raised, and attention should also be paid to supplementing calcium-type nutrients.
3. Pay attention to abnormal phenomena
When river crabs shed their last shell, it is often the female crabs that shed their shells in a concentrated manner first, and about a week later the male crabs also begin to shed their shells in a relatively concentrated manner. This is a normal phenomenon. Farmers should patrol the pond 2-3 times a day to observe the feeding and activity of the river crabs as well as their shell-shedding condition. If it is found that river crabs have difficulty completing shell shedding, the causes should be carefully analyzed, whether it is caused by water quality problems or insufficient nutrition, etc., and timely discovery, timely elimination and timely remedial measures should be taken to ensure that the river crabs shed their last shell well and quickly fatten and gain weight, in order to increase output and improve farming benefits.