Role of Fish Meal in Animal and Aquaculture Feeds

Fish meal is one of the most nutrient-dense feed ingredients available in animal agriculture today. Produced by drying and grinding whole fish or fish processing waste into a fine powder, it delivers a concentrated package of high-quality protein, essential amino acids, omega-3 fatty acids, and vital minerals. Whether it’s boosting broiler growth on a poultry farm, improving piglet survival rates, or providing the ideal nutrition for farmed shrimp, fish meal plays a central role in feed formulations across the livestock and aquaculture industries. Let’s break down exactly how fish meal works in each of these sectors – and why it continues to be so valued despite rising costs and growing interest in alternatives.

What makes fish meal nutritionally superior 🔗

Fish meal stands apart from other protein sources primarily because of its protein concentration and amino acid balance. High-quality fish meal typically contains between 60% and 72% crude protein by weight, making it one of the most concentrated protein sources available for animal feeds. But the real advantage is not just the quantity of protein – it’s the quality.

The protein in fish meal contains all ten essential amino acids that farm animals need, in proportions that closely match their biological requirements. It is especially rich in lysine and methionine, two amino acids that are frequently deficient in plant-based feed ingredients like soybean meal and corn. Lysine is critical for muscle development, while methionine supports protein synthesis, feather formation in poultry, and a range of metabolic functions. Plant-based proteins often fall short on these amino acids, requiring expensive synthetic supplementation to fill the gap.

Beyond amino acids, fish meal provides omega-3 fatty acids – specifically EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) – which support brain development, immune function, and inflammation regulation in animals. It also supplies a broad range of minerals including calcium, phosphorus, magnesium, potassium, and selenium, along with B-complex vitamins such as B1, B2, B6, and B12, as noted by the FAO and IFFO. This combination of nutrients in a single, highly digestible ingredient is difficult to replicate with any other feedstuff.

Another key advantage is digestibility. Overall protein digestibility values for fish meal consistently exceed 95%, whereas digestibility of plant-based proteins can vary widely – sometimes dropping as low as 77% depending on the plant species. This is because plant proteins are often bound with indigestible carbohydrates and fibre components that reduce nutrient availability. Fish meal also lacks the anti-nutritional factors commonly found in plant ingredients, such as trypsin inhibitors in soybeans or gossypol in cottonseed meal, which can interfere with digestion and even cause toxicity.

Fish meal in poultry feeds 🔗

Poultry nutrition has long relied on fish meal as a premium protein source, and for good reason. Broilers, layers, and breeding birds all benefit from the nutrient density that fish meal brings to their diets.

Why poultry needs fish meal 🔗

Corn-based poultry diets are commonly deficient in lysine and methionine – two amino acids that are essential for rapid muscle growth, feather development, and egg production. Fish meal bridges this nutritional gap efficiently. According to the University of Kentucky’s Cooperative Extension Service, fish meal provides high levels of methionine and lysine alongside a good balance of unsaturated fatty acids, available phosphorus, and vitamins A, D, and B-complex.

In broiler diets, fish meal supports faster weight gain and improved feed conversion ratios – meaning birds convert more of what they eat into body mass. For laying hens, the mineral content (particularly calcium and phosphorus) contributes to stronger eggshell formation, while the omega-3 fatty acids can improve yolk quality and nutritional value for consumers.

Recommended inclusion rates 🔗

Fish meal is typically included at 5% to 10% of the total poultry diet. In broiler starter feeds, the inclusion rate tends to be higher (around 5-8%) to support rapid early growth, while in grower and layer feeds it is usually reduced to 3-5%. These levels are sufficient to supply the essential amino acids and minerals without causing palatability issues or excessive feed costs.

Storage and quality concerns 🔗

One important consideration with fish meal in poultry feeds is proper storage. Fish meal is inherently unstable – it can spontaneously combust if not stored correctly, and improperly stored meal may develop high levels of biogenic amines like histamine, which can cause gizzard erosion in chickens. Commercial fish meal is stabilised with antioxidants (commonly ethoxyquin) to prevent oxidation and preserve nutritional quality. For organic poultry operations where synthetic antioxidants are not permitted, natural alternatives based on tocopherols (vitamin E) and rosemary extract are available.

Fish meal quality also varies depending on the fish species used and the processing method. Colour, smell, texture, protein content, and moisture levels are all indicators of quality. Good fish meal should have a golden-yellow to light-brown colour, a fresh fishy smell (not rotten), and a minimum protein content of 55%.

Fish meal in livestock feeds 🔗

Beyond poultry, fish meal plays a valuable role in the nutrition of pigs, cattle, and other livestock – particularly during critical growth stages.

Swine nutrition 🔗

Pigs have digestive systems that are efficient at utilising the high-quality protein in fish meal. Inclusion rates in swine diets typically range from 5-10% in piglet (starter) feeds and about 2-4% in grower-finisher feeds. The Feedipedia database notes that fish meal is beneficial in starter and weaned pig diets at rates below 10%, and that it has even been found to reduce post-weaning diarrhoea due to its hypoallergenic properties. Inclusion above 10%, however, is generally not considered economically viable.

Fish meal’s contribution of vitamins, omega-3 fatty acids, and highly available minerals is especially useful for young pigs during their most vulnerable growth phase. The readily available phosphorus supports bone development, while the amino acid balance promotes lean muscle growth and improved carcass quality.

Ruminant feeds 🔗

The use of fish meal in ruminant (cattle, sheep) nutrition is more restricted. It has been banned for ruminants in the European Union since 2000 and is similarly restricted in countries like Australia. However, where permitted, fish meal is valued as a source of bypass protein – the cooking process during production causes protein binding, which allows the protein to resist breakdown in the rumen and reach the small intestine for more efficient absorption. Studies have shown that fish meal can improve amino acid balance and reduce nitrogen excretion in lactating dairy cows compared to other undegradable protein sources.

Fish meal in aquaculture feeds 🔗

If there is one sector where fish meal is truly indispensable, it is aquaculture. Farmed fish and shrimp have evolved to consume other aquatic organisms, making fish meal a natural fit for their nutritional needs and digestive capabilities.

Why aquaculture depends on fish meal 🔗

According to NOAA Fisheries, fish meal and fish oil provide an almost perfect balance of the approximately 40 essential nutrients that fish need to stay healthy and grow – the same reason seafood is so nutritious for humans. The amino acid profile of fish meal closely mirrors what farmed fish would consume in their natural habitats, and its excellent palatability encourages strong feed intake.

Fish meal inclusion rates in aquaculture feeds vary significantly by species. Carnivorous species like salmon and trout historically required diets containing 30-50% fish meal, though this has decreased substantially through research into alternative ingredients. The amount of fish meal in salmon diets, for example, dropped from roughly 70% in the 1980s to about 25% by 2017. For herbivorous and omnivorous species like carp, catfish, and tilapia, inclusion rates may be as low as 5-7%, and all-plant protein diets have been used successfully to grow these species to market size. However, larvae and young fish of nearly all species still require fish meal for optimal growth.

Fish meal in shrimp feeds 🔗

Shrimp farming is one of the largest consumers of fish meal in the aquaculture sector. Commercial shrimp feeds typically contain 10-30% fish meal as a high-quality protein source and feeding attractant. Shrimp rely entirely on chemosensory systems to detect and locate food, which makes the palatability of fish meal particularly important – it helps ensure rapid location and complete ingestion of the feed pellets.

A University of Stirling study noted that fish meal inclusion in shrimp feeds dropped from 19-40% in 2000 to 11-23% in 2014, driven primarily by rising prices and sustainability concerns. The shrimp industry consumes approximately 31% of all fish meal used in aquaculture globally, making the search for effective alternatives particularly urgent in this sector.

The role of fish meal in feed palatability and digestibility 🔗

One often-overlooked benefit of fish meal in aquaculture feeds is its role as a palatability enhancer. Adding fish meal to diets that rely heavily on plant-based proteins improves feed acceptance, intake rates, and overall feed conversion. This is because fish meal contains specific compounds – including free amino acids and small peptides – that act as natural feeding stimulants. When alternative protein sources are used to replace fish meal entirely, reduced palatability frequently leads to lower feed intake and slower growth.

Fish meal also works synergistically with other protein sources in the diet. Its balanced amino acid composition complements the nutritional profiles of plant and animal proteins, promoting faster growth and reducing overall feeding costs even when included at moderate levels.

Sustainability challenges and the search for alternatives 🔗

Despite its nutritional advantages, fish meal faces significant sustainability and economic pressures. Global fish meal production has remained relatively stable at around 6-6.5 million tonnes annually, but demand has increased steadily – particularly from the rapidly growing aquaculture sector. This supply-demand imbalance has driven prices upward, with fish meal often costing two to three times more than soybean meal.

Environmental concerns centre on the reliance on reduction fisheries – industrial fleets that target small pelagic fish like anchovies, sardines, and menhaden specifically for processing into meal and oil. While the fish meal industry maintains that these fisheries are managed sustainably, critics point to potential impacts on marine ecosystems and food chains. It is worth noting, however, that an increasing proportion of fish meal now comes from fish processing by-products rather than dedicated fisheries, improving the sustainability profile of the ingredient.

Alternative protein sources 🔗

Significant research is underway to identify protein sources that can partially or fully replace fish meal in animal feeds. The most commonly explored alternatives include:

Soybean meal is the most widely used substitute, but it contains anti-nutritional factors and has an imbalanced amino acid profile (low in methionine) that limits its effectiveness as a complete replacement. Poultry by-product meal has shown promise in aquaculture, with some studies demonstrating comparable growth performance to fish meal-based diets. Insect meals, particularly from black soldier fly larvae, are emerging as a sustainable option – they can be reared on food waste and plant by-products, and research shows they can replace up to 50-60% of fish meal in shrimp feeds without negatively affecting growth. Other alternatives include single-cell proteins (from bacteria, yeast, or microalgae), krill meal, and various rendered animal meals.

However, no single alternative currently matches fish meal’s complete nutritional package – its amino acid balance, digestibility, palatability, and micronutrient content. The most practical approach for the near future involves strategic partial replacement, using combinations of alternative ingredients while retaining a core inclusion of fish meal to ensure optimal animal performance.

Quality parameters and storage best practices 🔗

The nutritional value of fish meal is only as good as its quality, which depends on the raw material, processing method, and storage conditions.

Key quality indicators 🔗

Protein content should be a minimum of 55-60% for use in poultry and livestock feeds, with premium grades reaching 65-72%. Freshness is critical – measured by indicators such as total volatile nitrogen (TVN) levels, which should ideally stay below 120 mg/100g. Moisture content should be maintained between 6-10%, as higher levels encourage mould growth and mycotoxin formation. The drying process during manufacturing is particularly important – over-drying can scorch the meal and reduce its nutritional value, while under-drying creates conditions for spoilage.

Storage recommendations 🔗

Fish meal should be stored in cool, dry, well-ventilated conditions, away from direct sunlight and moisture. Antioxidant treatment is essential to prevent lipid oxidation, which degrades the omega-3 fatty acids and produces off-flavours that reduce palatability. Containers should be sealed properly after each use. Adulteration with fillers like sand, cassava flour, or excessive bone content is a risk in some markets, so purchasing from verified suppliers and conducting regular quality testing is advisable.

The bigger picture: fish meal and sustainable animal farming 🔗

Fish meal occupies a unique position in animal agriculture. It transforms fish processing waste and small pelagic species that are not suitable for human consumption into a high-value ingredient that enhances productivity across multiple livestock sectors. NOAA reports that globally, aquaculture uses roughly half a metric tonne of wild whole fish to produce one metric tonne of farmed seafood, meaning the sector as a whole is a net producer of fish protein.

As the global demand for animal protein continues to grow, the strategic use of fish meal – combined with continued research into alternative ingredients and improved processing technologies – will remain essential for balancing productivity, animal health, and environmental responsibility. The challenge ahead lies in optimising fish meal use through precision nutrition, reducing waste, and scaling up viable alternatives to ensure long-term sustainability.

What do you think? As alternative protein sources like insect meal and single-cell proteins become more commercially available, do you see fish meal eventually being replaced entirely – or will it always hold an essential place in animal and aquaculture nutrition?

References

1. https://edis.ifas.ufl.edu/publication/FA122
2. https://www.iffo.com/node/338
3. https://poultry.extension.org/articles/feeds-and-feeding-of-poultry/feed-ingredients-for-poultry/animal-by-products-in-poultry-feeds/fishmeal-in-poultry-diets/
4. https://www.feedipedia.org/node/208
5. https://www.fisheries.noaa.gov/insight/feeds-aquaculture
6. https://www.sciencedaily.com/releases/2019/04/190412101254.htm
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC12226199/