How to fix an asymmetric distribution of weights?

As was outlined in detail in the Impact of fixing an asymmetric distribution article, it is critical to pay attention to and resolve issues related to the symmetry of the distribution of weights to ensure a good harvest. In this article, we detail the specific actions you can take to resolve asymmetrical weight distributions. 

Hand Feeding

When a significant portion of shrimp is more than 2g below your average weight, it is important to target these shrimp in order to get them eating well and growing faster. You can do this by hand-feeding the shrimp which are in locations further from current feeding zones. In this example, 20% of animals are less than 2g below the average weight. This gives an idea of how much to be feeding in the zones away from the current feeding zones.

Increase Autofeeder Density

If the autofeeders are emptying before you refill them, or if there are large areas of the pond without feeders where smaller shrimp can be found, you should increase the number of feeders that are on the pond. For most types of autofeeders, it can be necessary to have up to 1.5-2 feeders per Ha, and moving them regularly within the cycle is important to avoid feeding on top of bad pond bottom conditions. 

Pellet Mixing

Using the xpertSea MAX pellet calculator, you can quickly see what the breakdown of the pond is and how you should be feeding. If there are more than 10% of biomass that needs a different pellet size, you will see significant benefits by mixing pellet sizes.

For more details on pellet mixing, check out the post on Using xpertSea MAX to feed the right pellet sizes.

Increase Aeration

If you are experiencing oxygen issues or shorter feeding windows due to the oxygen not getting high enough, it can be worthwhile to invest in additional aeration to increase the oxygen levels of the pond. This will create a better environment for the shrimp, and they will better consume feed. 

Partial Harvest

If the shrimp are at an appropriate size and the pond is close to carrying capacity, you can partially harvest the pond. This will give smaller shrimp more space to grow, while also harvesting some of the bigger animals. When you monitor after a partial harvest, you should see that some of the asymmetry has been resolved and the growth rate may improve. 

Full Harvest

In the case where the shrimp are consuming the feed, but the smaller shrimp are not growing and the distribution is increasing, your FCR could be at significant risk. The feed being given to the pond is not being converted to biomass, and therefore will have a significant impact on profitability. In this case, doing an earlier harvest should be considered to protect your FCR and overall profitability.

To receive specific, actionable insights on how to fix asymmetry in your ponds, contact us at info@xpertsea.com to learn more or to bring xpertSea MAX to your farm.