The inclusion of krill meal means higher feed intake and growth after seawater transfer as well as higher growth in the grow-out stage, as shown in numerous studies. Quite simply, salmon likes the taste of krill. Reasons are attractants such as TMAO, nucleotides and other water-soluble amino acids (Hatlen et al., 2016).
Krill is a feeding attractant that prevents feed intake depression from plant-based diets. It even reduces feed depression during the seawater transfers (Zhang et al., 2012).
Feeds with krill meal provide the right balance of essential fatty acids (omega-3 vs. omega-6), promoting a strong immune system in fish. While too much omega-6s can lead to increased inflammation, omega-3s have anti-inflammatory effects. For example, studies have shown that fish fed on krill meal are more robust, develop stronger heart muscles and healthier circulatory systems. This results in better survival and boost immune system. Win, win (Mørkøke et al., submitted).
As phospholipids are easily taken up by the organs, more of the omega-3s go directly to cell membranes, rather than being stored as fat. This results in better fillet firmness and makes the fillet more suitable for industrial handling, as well as making it more appealing for end consumers (Hatlen et al., 2016).
Connected to the previous point, salmon fed krill meal also suffer less from gaping. Gaping occurs when muscle blocks separate, creating gaps in the salmon fillet. These gaps spoil the appearance of the fillet, ultimately leading to reduced sales, as consumers don’t want to buy fillets with such cosmetic issues (BioMar/ Nofima internal report, 2014).
Because omega-3s have anti-inflammatory effects, salmon fed a diet containing krill are less likely to develop melanin spots. Less inflammation equals to less melanin spots (BioMar/ Nofima internal report, 2014).
The colour of fillet from salmon fed dietary krill meal is even and has a nicer pink colour, which consumers prefer. Krill contains astaxanthin, a natural antioxidant, which in addition is also a natural source of pigmentation and provides fillet the nice pink colour (Mørkøke et al., submitted).
Krill meal reduces fat deposition in fillets. This is due to the phospholipids in krill meal that influence the lipid transport and deposition in fish organs (Hatlen et al., 2016; (Mørkøke et al., submitted).
Krill is one of the most abundant species on earth with a biomass of around 500 million tons. Compared to other fisheries, where precautionary catch limits are set to 10% of the biomass the total allowable catch of Antarctic krill is set to 1% of the biomass. However, only 0,5% is caught annually. Krill is a sustainable source of protein, omega-3 phospholipids, feed attractants and astaxanthin.
Antarctic krill lives in the pristine waters of Antarctica. It is at the bottom of the food chain, feeding on plankton, which means it has very low levels of dioxins and dioxin-like PCBs. Choose QRILL Aqua, a natural, proven, performance feed ingredient.