In order to ensure a successful shrimp farming process, it's essential to start with proper pond preparation. Clearing the pond is crucial, and using insecticides can be very effective in reducing disease risks and improving survival rates. If you use bleach for disinfection first, followed by an insecticide treatment, the results will be even better. When applying bleaching powder, make sure to keep the water depth at around 30 cm. Dissolve the powder in a boat cabin, then one person can push the boat forward while another sprays the solution evenly. A large quantity of bleaching powder is typically used. It's efficient to pre-place the medicine on the pond dam, so that any spilled material can be quickly retrieved nearby, saving both time and labor.
For the insecticide application, maintain a water depth of about 20 cm at the bottom of the tank. The liquid insecticide should be sprayed uniformly according to the required concentration. After 10 days of treatment, flush the pond three times to reach an average water depth of 1 meter. Install 60-mesh filter screens at the inlet to prevent wild fish, crabs, and other predators from entering, as they can cause significant losses—up to 80% of the shrimp may be eaten if not controlled. Maintaining a consistent water depth of at least 1 meter not only provides enough space for the shrimp but also enhances the pond’s natural water purification ability.
Another important aspect is the cultivation of plankton, particularly copepods, which serve as a high-quality food source for shrimp. A higher population of copepods usually indicates better water quality and healthier shrimp growth, leading to higher survival rates. For optimal stocking density, aim for 80,000 seedlings per mu (approximately 667 square meters), with each seedling measuring about 1.0 cm in length. Too low a density reduces pond utilization, while too high a density can lead to a sharp decline in plankton levels, affecting both the shrimp's food supply and the pond’s ability to self-regulate water quality.
Maintaining a balanced density helps stabilize the ecosystem, ensuring that plankton populations remain healthy and the water environment remains stable. In practice, a seeding rate of 5 kg per mu has proven effective in regulating water quality. This is because certain species like earthworms feed on phytoplankton, which indirectly supports copepod populations. Properly managed plankton communities help maintain a balanced aquatic environment, which is essential for high survival rates of shrimp seedlings.
It's important to clarify that the term "broadcast" here refers to the initial seeding of small seedlings, not larger ones. Large fish should not be mixed with shrimp in the same pond, as they can over-consume phytoplankton and negatively impact copepod populations. Additionally, ponds treated with insecticides should not be used for temporary shrimp raising, as this can lead to poor survival rates, even without visible disease symptoms.
The timing of seedling introduction is also critical. It's best to introduce seedlings around June 25th, and if possible, delay the release slightly to avoid disease outbreaks. Avoid releasing them at the same time as normal shrimp, as this increases the risk of disease transmission. Ideally, the holding period should be kept to 30 days.
After using insecticides to clean the pond, it's necessary to supplement with fertilization and feeding to support plankton growth. Avoid overfeeding, as excessive food can pollute the water. Feed approximately 0.05 kg per ten thousand seedlings daily, and avoid feeding on rainy days. Before stocking, apply a mix of chicken manure and chemical fertilizers. In the early stages, apply 17 kg of chicken manure, 6.4 kg of ammonium bicarbonate, and 1.6 kg of diammonium phosphate per mu. During the growing phase, top-dress with 8 kg of chicken manure, 1.1 kg of ammonium bicarbonate, and 0.4 kg of diammonium phosphate per mu, repeating this process three times.
The balance of plankton depends on nutrient availability and the feeding activity of farmed animals. Initially, plankton abundance remains high due to low feeding pressure, but as shrimp grow, nutrient levels may not increase proportionally, leading to a decline in plankton. Adjust fertilization accordingly, especially when water transparency drops below 40 cm. After heavy rain, when water conditions change rapidly, it's crucial to increase fertilization to restore plankton levels.
Organic fertilizers are preferable as they provide long-term benefits and promote the growth of zooplankton. However, they can make the water cloudy. Chemical fertilizers, while fast-acting, have lower efficiency and tend to be absorbed by sediment. Mixing organic and chemical fertilizers offers the best results, combining the advantages of both.
Shrimp quality is key to successful farming. Ensure that the seedlings are of sufficient quantity and uniform size. Even within the same nursery, there can be variations in seedling quality. It's common to purchase high-quality seedlings from outside and acclimate them in local nurseries before transferring them to the main pond. Transport seedlings in oxygenated plastic bags, with a maximum density of 25,000 per bag, filled with 1/3 water and 2/3 oxygen. Handle them carefully during transport to avoid damage.
When first introduced, shrimp may appear densely packed, but they gradually spread out. Within 10 days, they typically grow to about 1.5 cm. Shrimps prefer warmer, shallow waters initially, but as temperatures rise above 28°C, they move to deeper areas. They are less active on rainy or moonlit nights.
If shrimp grow too quickly and then their growth slows down, it could signal the onset of disease. Monitoring their behavior and growth patterns is essential for early detection and intervention. Finally, the entire holding process is short-term, aiming to produce large-sized seedlings of at least 2.5 cm in a short period. These practices are specifically tailored for breeding seedlings, not for general shrimp farming, which involves different techniques.
Foshan Ja Suo Medical Device Co., LTD , https://www.jasuodental.com