Krill meal improves salmon health and fillet quality

Atlantic salmon fed on a diet where fishmeal was substituted with krill meal during the finishing feeding period had positive effects on health parameters and meat quality.

May 7, 2020

The Norwegian Institute of Food, Fisheries and Aquaculture (Nofima), in collaboration with Aker BioMarine, recently released a study looking into the health and fillet quality of Atlantic salmon after a period of dietary krill supplementation. The study, now published in the British Journal of Nutrition, investigates the health parameters and meat quality of Atlantic salmon fed a diet where fishmeal was substituted with krill meal during the finishing feeding period. Overall results reveal that krill meal improved the welfare and fillet quality of the salmon.

“Antarctic krill meal has sparked the interest of marine researchers due to its nutritional profile. Previous studies have shown the proven effects of krill, with this study we wanted to uncover the basic mechanisms behind these effects, on farmed Atlantic salmon. The overall goal is to improve the systemic understanding of dietary krill meal effects on a biochemical, morphological and molecular level,” said Turid Mørkøre of Nofima and author of the study.

Researchers picked out 800 Atlantic salmon, weighing 2,270 grams each and randomly distributed across eight sea cages at the LetSea feed trial unit in Norway. The study experimented with supplementing krill meal (12%) in a low fishmeal diet (5%) among salmon. All feeds were designed to meet the nutritional requirements of salmonid fish, with balanced EPA and DHA content. After a ten-week trial, fish were bulk weighed and 20 fish from each sea cage were randomly selected for analysis.

The results

Overall, the study revealed positive effects on salmon health. Key findings include specific improvements in:

Body shape – krill meal inclusion led to more voluminous body shape and higher condition factors.
Heart health – krill meal inclusion led to reduced fat accumulation around the heart.
Fillet quality – krill meal inclusion led to a more ordered and stable collagen architecture and better muscle integrity.
Immune genes – krill meal inclusion resulted in a boosted expression of immune genes in liver including enhanced liver coloration and increasingly responsive structural genes.
Hindgut – krill meal inclusion led to less inflammation in the hindgut and zero mucus presence.

“We knew that nourishing salmon with krill supplemented diets benefit salmon performance, overall health and fillet quality. With these new findings, we now also understand why,” said Tibiábin Benítez-Santana, director R&D fish nutrition, Aker BioMarine. “This study is an important step in fish diet and welfare research. Krill represents the single largest marine biomass on Earth. That, coupled with its powerful nutritional value as shown in this study, as well as the sustainable methods of harvesting, make Antarctic krill meal a natural contender as a supplement in low fishmeal diets.”