# Utilisation of Inorganic Phosphates in Standard Diets for Whiteleg Shrimp Litopenaeus vannamei (Boone, 1931)

## TL;DR

This study explores how different inorganic phosphate additives affect nutrient digestibility and waste in whiteleg shrimp diets, aiming to reduce environmental impact.

## Contribution

The study identifies optimal phosphate sources that improve nutrient efficiency and reduce nitrogen and phosphorus waste in shrimp diets.

## Key findings

- Monoammonium phosphate (MAP) and Control diets generated the highest nitrogen waste.
- SCP-2% diets produced the lowest nitrogenous waste and highest calcium digestibility.
- Phosphate inclusion did not affect shrimp growth but reduced phosphorus and calcium retention.

## Abstract

This study examined the impact of inorganic phosphate additives on nutrient digestibility, waste generation, and performance of Penaeus vannamei. Regarding to P digestibility, monosodium phosphate (MSP) showed the highest values. SCP-2% (sodium calcium phosphate with 2% sodium incorporation) diet showed the highest values of Ca digestibility. Although nitrogen and phosphorus excretion did not differ significantly, residue analysis showed that SCP-2% diet produced the lowest nitrogen waste, while monoammonium phosphate (MAP) and the Control diet generated the highest levels. Phosphorus residues were greatest in the Control diet, followed by MSP. Overall, phosphate inclusion did not influence shrimp growth, survival, or body composition, but phosphorus and calcium retention declined as their dietary levels increased, highlighting the need to optimise phosphate sources for improved nutrient efficiency and reduced environmental impact.

Aquaculture effluents rich in phosphorus and nitrogen (P and N) can lead to eutrophication of aquatic ecosystems. These nutrients may contribute to harmful algal blooms, oxygen depletion, and deterioration of water quality, which poses a threat to aquatic biodiversity. In shrimp diets, environmental impacts from P and N nutrient leaching can be reduced by improving dietary P digestibility through the use of alternative ingredients. While fishmeal, with its high phosphorus content, has traditionally been a primary source, its declining use due to cost and limited availability necessitates the inclusion of inorganic P sources to meet shrimp nutritional requirements. Optimising these sources ensures adequate phosphorus availability while minimising nutrient waste. This study evaluated the effects of inorganic phosphate supplementation (monoammonium phosphate, MAP; monosodium phosphate, MSP; and sodium calcium phosphate, SCP-2%) in standard diets (35% CP) on nutrient digestibility, residue generation, and performance of Litopenaeus vannamei. Results showed that phosphorus digestibility exceeded 96% across all phosphate sources, with MSP achieving the highest values. Calcium digestibility was notably higher in diets containing monocalcium phosphate, such as SCP-2%, which demonstrated superior digestibility values. No significant differences were observed in nitrogen or phosphorus excretion; however, residue analysis revealed that SCP-2% diets generated the lowest nitrogenous waste relative to ingested nitrogen, whereas MAP diets produced the highest nitrogen residues, followed by the Control diet. For phosphorus residues, the Control diet showed the greatest proportion relative to ingested phosphorus, followed by MSP. Phosphate inclusion did not affect shrimp growth, survival, or body composition. However, phosphorus and calcium retention efficiencies were inversely proportional to their dietary content, underscoring the importance of optimising phosphate sources to enhance nutrient utilisation and minimise environmental impact.