Why shrimp prefer the taste of Euphausia superba
Krill meal is in itself a natural attractant, and as a chemostimulant helps increase the duration shrimp spend feeding, and by connection the amount eaten (Derby et al. 2016). Krill meal contains chitin from the exoskeleton, soluble compounds, such as trimethylamine oxide, as well as free amino acids and nucleotides. This combination, naturally found in Antarctic krill, Euphausia superba, is proven to help increase both feed attractability and palatability. To put it in simple terms, shrimp just likes the taste of krill. The result is enhanced shrimp growth and yield, meaning shrimp spend less time in the ponds and get to market faster.
The study on Litopenaeus vannamei further revealed that by adding 6% krill meal to pellets, consumption was significantly increased by 29% within one hour (Derby et al. 2016). After three hours, 6% krill meal increased pellet consumption by 69% over the control.
In another study on L. vannamei, it was illustrated that even low inclusions of krill spares fish meal and improves feed efficiency under high salinity conditions. Feed efficiency is enhanced starting at a 3% dietary inclusion of krill meal and feed conversion ratio (FCR) improved. A feed containing 5% krill meal and 7% fish meal is more palatable than a feed with 15% fish meal and 1% squid meal. (Nunes et al. 2017).
Stepping in as a cholesterol replacement
Cholesterol has also become a vital nutrient in shrimp feed, assisting the development of membrane function, lipoprotein transport, hormone production and absorption/transport of fatty acids. Shrimp have limited natural ability to make cholesterol on their own and show reduced growth if insufficient cholesterol is present in the diet. However, dietary cholesterol tends be expensive, and its availability is inconsistent.
As cholesterol uptake and distribution in shrimp depends on the availability of phospholipids, the omega-3 phospholipids present in krill meal ensure that fats (cholesterol and triglycerides) are efficiently emulsified and digested, stored in the hepatopancreas and mobilized when required, eliminating the need for dietary cholesterol supplementation.
An ingredient for the future
Krill is a natural ingredient, sustainably sourced and packed with omega-3 fatty acids (bound to phospholipids) and highly digestible peptides. Including krill meal in your shrimp feed will help improve growth, stress resistance and survival of larvae, post-larvae and juveniles.