Balancing Energy and Amino Acids for Shrimp Across Culture Temperatures 

Balancing amino acid supply and energy partitioning between protein, lipid, and carbohydrate sources is central to shrimp nutrition, and the optimum balance can shift with water temperature. This study, led by Keke Zheng and Jeleel Agboola, investigates how different proportions of digestible protein, lipid, and starch at a constant digestible energy level affect shrimp performance, nutrient utilisation, and gut microbiome composition under optimal and sub-optimal culture temperatures. 

Nine isoenergetic diets were formulated using a mixture design, varying the contributions of digestible protein (40–72%), digestible lipid (12–34%), and digestible starch (8–30%) to digestible energy. 

Results 

Growth Performance 

Shrimp grew 2-fold faster at 29 °C (than at 24 °C. Diets with a higher proportion of digestible energy from protein supported the highest growth rates regardless of temperature, confirming the crucial role of protein in shrimp performance at any given culture condition. 

Feed Utilisation 

Feed conversion ratio also responded to energy partitioning, with the best FCR values observed in diets where digestible energy came primarily from protein. The pattern was consistent at both 24 °C and 29 °C (FCR range 1.0–1.9). 

Protein Retention and Sparing Effects 

At both temperatures, diets with higher proportions of digestible energy derived from starch supported higher protein retention than diets with higher lipid, indicating a stronger protein-sparing effect of carbohydrates in shrimp. 

Gut Microbiome 

Temperature had no significant effect on microbial richness or diversity. Diet composition was the dominant factor: high-starch diets promoted higher microbial diversity than high-protein or high-lipid diets, likely reflecting greater carbohydrate availability for fermentation in the gut. 

The findings emphasize the important role of balanced energy source in promoting growth and feed utilization in shrimp. Protein remains the most efficient driver of growth, but starch can be used strategically to spare protein and enrich the gut microbiome at the same time. Lipid showed a similar utilisation efficiency to starch for growth but a weaker protein-sparing effect. For shrimp producers operating across a range of temperatures, these results support more precise feed formulation that balances cost, performance, and nitrogen output without sacrificing growth. 

About the Scientists