New binders enhance feed quality for white shrimp

In the aquaculture industry, success hinges on one critical factor: feed efficiency. The white shrimp, Litopenaeus vannamei, is one of the most nutritionally and commercially valuable species worldwide. However, shrimp exhibit a peculiar feeding behavior: they are “slow feeders” that extensively manipulate their food before ingestion, which can lead to the dispersal of pellets in the water.

This mechanical manipulation triggers two serious issues: first, the leaching of essential nutrients before ingestion, and second, the deterioration of water quality due to disintegrated feed. To mitigate this, science seeks the perfect “glue”: binders.

Key Points

• Superior Stability: The use of binders such as polymethylcarbamide (PMC) and starch-gum blends drastically reduces feed disintegration in water.
• Intestinal Health: Shrimp fed with bound diets showed a more robust intestinal morphology, featuring increased wall thickness and immune cell presence.
• Hypolipidemic Effect: Certain binders significantly reduced cholesterol and triglyceride levels in the hemolymph of these crustaceans.
• Sustainability and Costs: Optimizing pellet durability is crucial for reducing waste, as feed accounts for 50% to 60% of total operating costs in aquaculture.

Testing the Binders

A team of researchers from the Department of Nutrition at Alexandria University and the Ghalioun Feed Factory in Egypt evaluated three types of binders to determine the optimal balance between physical quality and biological performance. The experiment was conducted over three months with shrimp weighing approximately 9.3 grams.

The treatments included:

• Polymethylcarbamide (PMC) (G4): A 0.5% synthetic polymer.
• Control Group (G1): A basal diet without binders.
• Calcium Lignosulfonate (G2): Included at 1% of the diet.
• Starch + Gum (G3): A mixture based on guar gum, xanthan gum, and 0.4% starch.

Pellet Quality and Water Durability

The study revealed that the inclusion of binding agents is not merely a matter of form but a substantial technical improvement in the manufacturing of shrimp diets.

Stability and Leaching

Polymethylcarbamide (PMC) proved to be the most effective binder in terms of physical integrity. It recorded the highest water stability and the lowest leaching rate across all analyzed periods (30 min, 1h, and 2h). The starch-and-gum-based binder showed moderate results, outperforming both the control and lignosulfonate.

Water Activity (aw) and Preservation

A vital finding for food safety is the reduction of water activity (aw). Pellets with PMC and lignosulfonate recorded significantly lower aw levels. Low aw levels are preferable for protecting feed against bacterial and fungal growth during storage, ensuring a longer shelf life.

Comparative Table of Pellet Quality for White Shrimp

Impact on Shrimp Growth and Physiology

Although the physical quality of the pellet improved drastically, shrimp growth (final weight and weight gain) showed no statistically significant differences between groups during the three months. However, positive numerical trends were observed in specimens fed with PMC and starch + gum, which presented a better feed conversion ratio (FCR).

Internal Health and Metabolism

The research delved into how these components affect the shrimp’s “blood” (hemolymph). The use of binders generated a notable hypolipidemic effect:

• Glycemic Response: Diets with starch + gum and lignosulfonate increased glucose levels, suggesting that shrimp could utilize these binders as a secondary energy source.
• Lipid Reduction: Shrimp fed with PMC and starch + gum showed significantly lower levels of triglycerides and VLDL compared to the control.
• Cholesterol Control: The starch + gum group exhibited the most marked reduction in total cholesterol.

Intestinal Strengthening

Through histological analysis, it was discovered that binders improve the structure of the shrimp’s midgut. The groups fed with starch + gum and PMC showed:

• Improved epithelial cell morphology.
• Greater integrity of the intestinal folds.
• A more developed lamina propria with an increase in immune cells.
• Increased intestinal wall thickness.

Why Do These Binders Work?

The superiority of PMC is attributed to its low water absorption capacity, which limits pellet hydration and maintains its compact structure for longer. On the other hand, the starch and gum mixture works through a synergistic effect: the viscous properties of the gums increase the swelling of starch granules during gelatinization, creating a more resilient network.

In contrast, calcium lignosulfonate showed the lowest stability among the binders tested for shrimp. Although effective in other terrestrial species, it appears to absorb too much water in aquatic environments, softening the pellet prematurely.

Conclusions

The study concludes that the evaluated binders are beneficial for feed quality, although their impact on direct shrimp growth is limited in the short term.

1. Polymethylcarbamide (PMC) at 0.5%: This is the most technical option for maximizing stability and reducing leaching. However, its use is suggested for short culture periods to avoid potential long-term residual effects.
2. Starch + Gum at 0.4%: Positioned as the practical and safe alternative. It not only improves pellet quality but also promotes excellent intestinal health and a healthy lipid profile in shrimp with no detected adverse effects.

Reference (open access)
El-katcha, M. I., Soltan, M. A., Shewita, R. S., Marzouq, S. I., & El-Naggar, L. (2026). Pellet quality and growth performance of whiteleg shrimp, Litopenaeus vannamei, fed with different dietary pellet binders. Iranian Journal of Fisheries Sciences, 25(1), 85-103.

Milthon Lujan

Editor at the digital magazine AquaHoy. He holds a degree in Aquaculture Biology from the National University of Santa (UNS) and a Master’s degree in Science and Innovation Management from the Polytechnic University of Valencia, with postgraduate diplomas in Business Innovation and Innovation Management. He possesses extensive experience in the aquaculture and fisheries sector, having led the Fisheries Innovation Unit of the National Program for Innovation in Fisheries and Aquaculture (PNIPA). He has served as a senior consultant in technology watch, an innovation project formulator and advisor, and a lecturer at UNS. He is a member of the Peruvian College of Biologists and was recognized by the World Aquaculture Society (WAS) in 2016 for his contribution to aquaculture.