Feed costs represent a significant expense for shrimp producers. Reducing feed consumption while maintaining optimal growth performance is a critical challenge.
To mitigate these costs and improve profitability, many aquaculturists have explored alternative feeding strategies, such as feed restriction. A study led by researchers from the Federal University of Rio Grande-FURG (Brazil) and the Federal Rural University of Pernambuco-UFRPE (Brazil) aimed to evaluate the impact of feed restriction on the plankton community, growth, and economic performance of Penaeus vannamei cultured in a symbiotic system.
The High Cost of Feed in Shrimp Farming
Feed is a major expense for shrimp producers, representing a substantial portion of production costs. The high price of feed is primarily due to the reliance on fishmeal and fish oil, which have limited supply and are also used in other industries.
In addition to economic challenges, shrimp farming can have negative environmental consequences. Excessive feed input can lead to water pollution, as unused feed nutrients are released into the surrounding ecosystem. This can contribute to eutrophication and other environmental issues.
Feed Restriction as a Sustainable Solution
Feed restriction offers a potential solution to the economic and environmental challenges of shrimp farming. By reducing feed consumption, aquaculturists can lower costs and minimize nutrient release into the environment. Additionally, feed restriction can encourage shrimp to consume natural food sources, such as plankton, further reducing dependence on external feed inputs.
The Role of Symbiotic Systems
Symbiotic systems, which combine prebiotics and probiotics to promote the growth of beneficial microorganisms, can enhance the effectiveness of feed restriction in shrimp farming. These systems create a more natural environment for shrimp, encouraging them to utilize natural food sources and improving their overall health and well-being.
Potential Benefits of Feed Restriction in Symbiotic Systems
- Reduced Feed Costs: By reducing feed consumption, producers can lower production costs and improve profitability.
- Improved Feed Efficiency: Shrimp may exhibit compensatory growth after periods of feed restriction, leading to better feed conversion ratios.
- Reduced Environmental Impact: By minimizing nutrient runoff from unused feed, feed restriction can help protect aquatic ecosystems.
- Improved Shrimp Health and Well-Being: Symbiotic systems can provide a more natural and healthy environment for shrimp, promoting their overall well-being.
The Experiment
The researchers stocked juvenile P. vannamei in lined ponds and fed them a commercial diet for 60 days. Two treatments were established: partial feed restriction (FR) and a non-restricted control (WR). The ponds received organic (rice bran) and inorganic (urea) fertilization. The plankton community composition, shrimp growth parameters, and economic indicators were evaluated.
Results
- Plankton Community: No significant differences in the plankton community were observed between the FR and WR treatments. Both treatments exhibited a predominance of chlorophytes and protozoa.
- Shrimp Growth: Feed restriction resulted in a significant reduction in FCR, with values of 0.30 and 0.59 for FR and WR, respectively. This represents a 49.3% decrease in feed consumption per unit of weight gain. Other zootechnical parameters, such as growth rate and survival, were comparable between treatments.
- Economic Analysis: The main cost difference between the treatments was in feed expenditure. Feed restriction led to significant reductions in effective operational costs (21.8%) and total operational costs (20.2%). The breakeven point was also 18.8% lower in the FR treatment. Despite the cost reductions, both treatments demonstrated positive profitability indicators.
Benefits for the Shrimp Industry
The study’s findings suggest that feed restriction may be a viable strategy for Penaeus vannamei cultured in symbiotic systems. The observed reduction in FCR without compromising other zootechnical parameters indicates that shrimp can effectively compensate for reduced feed intake. This compensatory growth is likely attributable to the synergistic effects of the symbiotic system, which provides essential nutrients and promotes optimal gut health.
While feed restriction can generate significant cost savings, it’s important to note that offering feed throughout the production cycle can yield even greater profits. This is because a low FCR combined with a longer feeding period can result in greater overall shrimp production.
Conclusion
“Partial feed restriction in the cultivation of P. vannamei in a low-density symbiotic system (12 shrimp m−2) produced favorable results in terms of FCR, which was reduced by 49.3%,” the researchers conclude. They also report that the shrimp showed complete compensatory growth after the addition of inert diet, with no adverse effects on zootechnical performance.
In this sense, partial feed restriction in a symbiotic culture of P. vannamei is a viable strategy for improving economic efficiency. By reducing feed consumption without negatively affecting growth or plankton diversity, this approach offers a sustainable and profitable solution for shrimp aquaculture. Future studies should explore the long-term effects of feed restriction and investigate optimal feeding regimes for different culture conditions.
Reference
Gonçalves Junior, G. F., Wasielesky, W., Cardozo, A., Poersch, L. H. S., Brito, L. O., Krummenauer, D., & Fóes, G. K. (2025). Effect of feed restriction for Pacific white shrimp Penaeus vannamei in a semi-intensive synbiotic system: Plankton community, growth and economics. Aquaculture, 595, 741481. https://doi.org/10.1016/j.aquaculture.2024.741481
