A newly released study conducted at the University of Las Palmas de Gran Canaria, in collaboration with Aker QRILL Company and the University of Stirling, highlights the benefits of dietary krill meal inclusion for gilthead seabream (Sparus aurata) juveniles. This study was funded by AQUAEXCEL3.0, under the TNA program. The study shows that krill meal can improve nutrient utilization, optimize feed efficiency, and boost resilience against oxidative stress, contributing to a more effective aquafeed.
The study reveals that including krill meal in the diet significantly enhances fish health and stress tolerance, particularly during crowding challenges. This aligns with previous aquafeed trials with krill meal, reinforcing the ingredient’s potential to drive both sustainability and efficiency in the aquaculture industry.
Gilthead seabream is a highly valued species for aquaculture. However, crowded farming conditions often lead to oxidative stress, which affects fish health and growth. While traditional fishmeal has been the cornerstone of aquafeeds, its fluctuating supply and cost are driving a greater need for more sustainable alternatives.
“QRILL Aqua krill meal is a rich source of essential nutrients, including phospholipids and omega-3 fatty acids, which are vital for the health and growth of marine species like gilthead seabream. This study shows that krill meal inclusion can enhance the robustness of fish, especially under stressful conditions. This helps farmers achieve better fish performance while contributing to more sustainable operations,” said Kiranpreet Kaur, director of R&D Aquaculture, Aker QRILL Company.
Krill meal tested for nutrient efficiency and stress response
The 12-week trial, plus a seven-day crowding stress test, assessed the effects of varying krill meal levels (KM; 3%, 5%, and 7%) on growth, nutrient utilization, and oxidative stress responses during a stress challenge. The research team discovered that krill meal could replace up to 47% fishmeal in the diet, effectively maintaining growth performance while optimizing feed conversion ratio with higher lipid and protein efficiency ratios in gilthead seabream. Fish fed diets containing 5% and 7% krill meal also showed increased omega-3 levels in their red blood cells, supporting better resilience to crowding-induced oxidative stress. Although a similar trend was observed with the 3% KM showing a higher omega-3 index, the effect was more pronounced with the 5% and 7% KM.
Key findings of the study are:
- Feed efficiency: Fish fed QRILL Aqua krill meal diets maintained the same growth with improved feed efficiency (FCR), demonstrating that krill meal can partially replace fishmeal and leads to better utilization of feed nutrients
- Stress resilience: Fish fed krill meal diets retained higher levels of omega-3s in their blood during stressful conditions, indicating that QRILL Aqua could have a positive effect on faster recovery by limiting stress-related cellular damage.
- Nutritional value: Krill meal’s easily digestible omega-3s and natural nutrients helped the fish use energy more efficiently and build stronger defenses against stress.
“One of the standout findings of this study is how krill meal helps to sustain omega-3 index levels during and after a stress challenge and is associated with lower expression of antioxidant defense genes after stress, improving fish resilience under stressful conditions. This finding highlights the role of krill meal as a functional ingredient for maintaining fish health and welfare under typical farming conditions,” said Silvia Torrecillas, PhD, Institute of Agrofood Reserach and Technology (IRTA, Spain).
Based on the findings of this feed trial, researchers recommend including 5-7% krill meal in gilthead seabream diets to maximize nutrient utilization and support fish health during critical growth phases. By partially replacing fishmeal with krill meal, aquaculture producers can enhance performance and improve FCR while contributing to more sustainable feed practices.
Reference:
Marta Carvalho, Daniel Montero, Mónica Betancor, Kiranpreet Kaur, Antonio Serradell, Marisol Izquierdo, Rafael Ginés, Virginie Claeyssens, Silvia Torrecillas. Benefits of dietary krill meal inclusion towards better utilization of nutrients, and response to oxidative stress in gilthead seabream (Sparus aurata) juveniles. Aquaculture, Volume 598, 2025, 741957, ISSN 0044-8486, https://doi.org/10.1016/j.aquaculture.2024.741957
