Aquafeed

Fish farming is the world’s fastest-growing agriculture sector.  Fish feed is an integral component of fish farming.  The cost of fish feed accounts for a significant portion generally up to 50% but in some cases as high as 70% of an aquafarmer’s total production costs.

Fish protein usually in the form of fish meal and fish oil historically have been and still are key ingredients in most aquafeeds but are expensive due to increasing demand and declining catches of small wild fish (anchovies, sardines and pilchards) due to overfishing and climate change.

The prices of fish feeds key commodity components fish meal and oil have increased by more than 260% and 300% respectively over the last 20 years.

Compounding the shortage, fish meal and oil are used not only for aquaculture.  Petfood and animal stock feed industries compete with aquaculture for the raw materials used in fish feed.  Refined fish oil is increasingly being used as a human nutritional supplement.

Fish meats status is shifting from commodity to strategic ingredient.  There is major tension in the fish meal production market: while supply is declining largely due to over-exploitation of natural fish stocks, demand is increasing from the growing aquaculture industry.  According to a 2015 Rabobank report, fish meal is expected to shift from a commodity feed input to a “strategic marine protein” that commands a premium price.

FISH FEED INGREDIENT STRUCTURE

FISH FEED INGREDIENT STRUCTURE

Fish Meal

Peru is the largest fish meal producer and exports most of its product to China.

Fish meal typically contains 60-70% protein, 10-20% ash, 5-12% fat and has a high content of the fatty acids EPA and DHA, more commonly referred to as Omega-3 (IFTO 2011).

Fish Oil

Fish oil is generally produced from the press liquor obtained in producing fish meal from oily fish tissue.

Fish oil contains the Omega-3 fatty acids, EPA and DHA which are known to reduce inflammation in the human body and have other health benefits.

Interestingly, the fish used to produce fish oil do not actually produce Omega-3 fatty acids, but instead accumulate them by consuming either microalgae or krill, small shrimp and juvenile fish that have accumulated Omega-3 fatty acids.

Approximately 75% of the global fish oil supply is used for fish feed.

Chile is the largest fish oil producer.

Norway and Denmark are the largest importers of fish oil, which is largely used in the farmed salmon industry.

Filler

A component of fish feed which provides proteins and carbohydrates plus vitamins and amino acids, and which binds ingredients into pellets.

Wheat is commonly used as a binding agent in shrimp feed.

In others, soy meal may be added as a protein or other cereal-based additives may be used.


The increasing cost of fish meal and fish oil has forced feed manufacturers and fish farmers to shift feed composition to that of cheaper plant-based alternatives which now account for more than half of salmon fish feed inputs, and fish meal content has been reduced to 55%.

Historically aquafeed has been made in the form of pellets made from fish meal, fish oil and binding agents using a pellet press.

Aquafeeds can be used for feeding fish, and non-fish species such as shrimps, abalone and crabs.

The Percentage of Fish Meal Required in Feeds for Particular Species Varies Greatly

The Percentage of Fish Meal Required in Feeds for Particular Species Varies Greatly

Increasingly aquafeeds are being manufactured by extrusion (rather than pelleting machines) and can be produced to float or sink at various rates and in various sizes catering for the growth of the fish from the fingerling stage to harvestable size.

Different feeding regimes and nutritional feed content are delivered depending on the age and size of the fish.  At each stage of the life cycle, the carbohydrate, protein and fat content ratios of the feed need to be calibrated for the optimal health and growth of the fish.  For example, younger fish are fed multiple times per day in the nursery and production fish on the grow out sites are fed a protein sparing diet twice a day.

Compared to pelleted feed, extruded fish feed has the benefit that more of the feed is actually digested by the fish.  This results in more resource efficient production and less pollution.

With the increasing cost of fish meal and fish oil and the volatility of supply, feed manufacturers have reacted by changing feed composition.  As demonstrated in the figure below, cheaper plant based alternatives now account for more than half of salmon fish feed inputs, and fish meal content has been reduced by 55%.  However many fish farmers regard these plant ingredients as having anti-nutritional factors and in particular are concerned by the lower levels of Omega 3 in the final product.

Dramatic Shift in Fish Feed Components

Development of New Fish Feed Ingredients

The search is now on for new sustainable ingredients.  These substitutes will alleviate pressures on traditional fish meal sources.

  • Micro Algae and Seaweed: These marine plants possess nutrient profiles very similar to those of small wild fish.  Opportunities exist in scaling operations and new technology to cost-effectively grow algae.
  • Insects: Similar to algae and seaweed, insects, particularly those from a marine environment, are a promising fish meal alternative.
  • Krill: Meal made from krill can substitute for fish meal in fish feeds – but a sustainable supply is needed.  Opportunities lie in scaling up krill-farming operations.
  • Farmed Species: Fish, marine worms, mussels and similar aquatic animals can be used as fish feed inputs.  Opportunities exist in fish-farming technology and scaling current farms to achieve low costs.  In particular;  farming species that require lower feed input, such as tilapia, hold great potential.
  • Trimmings: Currently the industry sources 35% of fish meal from trimmings, a by-product of processed fish.  The majority of fish sold on the global market is unprocessed.  As value-added products of seafood proliferate, there will be an opportunity for utilization of fish trimmings.  Gathering by-products requires novel methods and sources – for instance, fish markets or restaurants.  Furthermore, for the trimming market to expand, so must refrigeration and storage capacity.

Fish silage or hydrolysate plants can produce alternative inputs for aquafeed production and are particularly suited for handling and stabilising fish waste.

ProEn-K – Plentex is playing a role in this area in endeavouring in conjunction with the University of the Philippines – Visayas, and Tarlac Agricultural University, to develop ProEn-K as a fish meal alternative in aquafeeds. 

For further detail refer to R&D.