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Capacity of Shrimp Ponds: Factors to Consider
from THE CRUST - ISSUE #7
by THE CRUST
give it to the shrimp instead. So that’s why the operation of these central drains of these shrimp toilets to remove organic matter is so important because it reduces basically 50 percent of the feed oxygen demand”, he said.
Another strategy to maintain and increase carrying capacity.
Despite the limiting factors that affect the carrying capacity of shrimp ponds, there are several ways to maintain and increase their capacity, such as improved feeds, automatic feeders, multiphase systems, and genetic improvement. These ways of using technology to increase productivity are called “Technification” by John. He said that this package of technology was successfully adapted by Ecuadorian and Vietnamese farmers.
John Hargreaves
For instance, Ecuador has been using improved feeds that are much better than they used 10 15 years ago. The improved feed is then combined with automatic feeders to ensure that the shrimp are fed on a regular schedule, preventing overfeeding and reducing waste. Besides that, these feeders can be equipped with timers or hydrophones acoustic sensors that can detect the shrimp appetite and a feedback mechanism to ensure consistent feeding.
“So now we’re feeding not just once or twice a day but every 10 minutes. And not only does that improve growth rate and feed efficiency, but it also allows you to increase the feed loading because that load is spread out during the day rather than concentrated in one or two feedings”, he added.
The other two strategies for improving carrying capacity are implementing a multiphase system and genetically improved seed. Ecuador and Vietnam have successfully implemented multiphase systems in different ways. Multiphase not only increases carrying capacity but also has other advantages, such as greater control over the production cycle, shorter production cycles, and betterprepared postlarvae for the growout phase.
“You can overlap the crops, you can get more crops per year, you get better survival and yield in grow out, you have better growth rate in the grow out systems because you’re stocking a larger animal, and it can just take off, and then you tend to have better feed conversion as well,” he revealed.
Implementing a onephase growout system, which is a common practice in Indonesia, by stocking very small postlarvae not only increases the risk of cultivation failure but also leads to suboptimal utilization of pond carrying capacity. Essentially, it is equivalent to leaving the pond’s carrying capacity underutilized.
Here is a table that illustrates the productivity and carrying capacity of multiphase systems in Vietnam, which John A. Hargreaves resumed
Table credit: John A. Hargreaves
Just like improved feed, improved genetics also plays a vital role in increasing carrying capacity. To illustrate the effect of genetics, John suggested considering three different strains of shrimp that can grow faster due to genetic improvement. One strain reaches market size in just 50 days, another takes 63 days, and the last takes 75 days. Which one would you prefer?
“By using good genetics, you can effectively manage carrying capacity by having more crop rotations per year. Instead of only having three crops per year, you can have up to five. This means that you can reach your carrying capacity much quicker, allowing for more efficient and profitable shrimp production. That’s the idea behind using good genetics to improve carrying capacity”, he concluded.
