A sustainable and nutritious additive for pet food

A special ingredient

It is not obvious that seaweeds can play an important role in the nutrition for pets, like cats and dogs. The protein content of most brown seaweeds is low, while there are a lot of carbohydrates. On the other hand, kelp seaweeds can contribute with a high content of iodine and minerals, omega-3 and omega-6 polyunsaturated fatty acids. The contents are so high that addition of only small amounts of sugar kelp to pet foods may cover the pets’ daily needs. For instance, the iodine content of sugar kelp may be as high as 6 g per kg wet seaweed. A dog with need for a daily intake of 3 mg iodine, only needs 0.5 g seaweed to cover its needs and too high levels may easily be reached.

Processing strategies

A current research strategy is to learn how to control the contents of the seaweeds by processing, that is, removing undesired levels of some of the components while maintaining the nutritious parts.

A simple and very effective method is boiling. Up to 90% reduction of the iodine content has been achieved by boiling sugar kelp and considering the high initial content this is clearly favourable. At the same time the amount of arsenic, cadmium and salt is significantly reduced, while the proteins and polyunsaturated fatty acids content is concentrated by boiling. Research on this is continuing.

Freezing and drying are other traditional techniques for preservation, but not as effective as boiling for removing undesired contents. Novel technologies like Pulsed Electric Fields, Ultrasound and High-Pressure Processing are currently under investigation. It will soon be known which are the most feasible for processing seaweed products for humans and pets.

Choosing the right macro algae

Sugar kelp (Saccharina latissima) is currently the most popular to culture in Europe, due to its fast growth and a taste that is most desirable. However, there are several other algae that, from a nutritional point of view, are much more promising, like dulse (Palmaria palmata), with its relatively high content of protein and omega-3.

Sustainability

Agriculture is under pressure from the expanding population and our needs for buildings, infrastructure and more food. While China and some other countries in Asia already have a long experience in farming along the coast, most western countries are in the very beginning of seaweed aquaculture. The potential is great, and increasing, as we learn how to move further offshore. Farming without using land and fertilisers is sustainable. There will be enough for sharing with our pets.