Quality Standards for Fish Meal: What You Need to Know

Fish meal is one of the most valued protein sources in the animal feed industry. It powers aquaculture, poultry, and livestock nutrition across the globe. But not all fish meal is the same. The quality of fish meal can vary dramatically depending on the raw material, the processing methods used, and how well it’s stored. That’s why quality standards exist – to help feed manufacturers, farmers, and buyers distinguish between good and substandard products. In India, the Bureau of Indian Standards (BIS) lays down specific criteria for grading fish meal, while international bodies like the IFFO (The Marine Ingredients Organisation) provide global benchmarks for quality assurance.

Why quality standards for fish meal matter 🔗

Fish meal is essentially a concentrated source of protein obtained by cooking, pressing, drying, and milling fresh fish or fish processing waste. According to Feedipedia, high-quality fish meal typically contains crude protein levels above 66%, fat content around 8-11%, and ash content below 12%. However, in many tropical developing countries, fish meal is sometimes produced through basic sun-drying and grinding, which can result in very high ash levels and relatively low protein content.

Without standardized benchmarks, buyers have no reliable way to judge what they’re purchasing. A bag labelled “fish meal” could contain anywhere from 40% to 70%+ protein, depending on the source and processing. Quality standards create a shared language between producers and buyers, ensuring transparency and fair trade. They also protect animal health – poor-quality fish meal with excessive contaminants or degraded protein can harm livestock rather than help them.

BIS grading system for fish meal in India 🔗

The Bureau of Indian Standards classifies fish meal into two primary grades based on chemical composition. This grading system, outlined under IS 4307, helps Indian feed manufacturers and buyers select the right product for their specific needs.

Grade I fish meal 🔗

Grade I represents the premium category. It requires a minimum crude protein content of 60% by mass. This grade comes from fresh, high-quality fish processed under controlled conditions. The BIS specifications also mandate that Grade I fish meal must have a maximum moisture content of 10%, crude fat no higher than 10%, ammoniacal nitrogen capped at 0.5%, acid-insoluble ash (AIA) limited to 3%, and sodium chloride not exceeding 4%.

Grade I fish meal is particularly suited for aquaculture operations raising carnivorous species like shrimp and marine fish, as well as for starter diets in poultry and young pigs. These animals have high protein requirements and benefit most from the superior amino acid profile that premium fish meal provides.

Grade II fish meal 🔗

Grade II fish meal requires a minimum of 50% crude protein. While lower in protein than Grade I, it still offers significant nutritional value for many feeding situations. The moisture limit remains at 10%, crude fat at 10%, and ammoniacal nitrogen at 0.5%. However, the permitted AIA is slightly higher at 5%, and sodium chloride is allowed up to 5%.

This grade often represents the best balance between cost and performance. Livestock operations raising broiler chickens, laying hens, or growing pigs commonly use Grade II fish meal as a protein supplement, especially when it’s blended with other protein sources in compound feed formulations.

Grade III fish meal 🔗

While the original BIS standard primarily defines two formal grades, fish meal with less than 50% crude protein is often informally referred to as Grade III. This lower-quality product usually results from processing inferior raw materials, excessive inclusion of bones and heads, or suboptimal manufacturing methods. It can still be used in maintenance diets or blended into multi-ingredient feeds where cost matters more than maximum protein concentration.

Key quality parameters beyond protein content 🔗

Protein content is the headline number for fish meal grading, but several other parameters are equally important in determining overall quality and safety.

Moisture content 🔗

The BIS specifies a maximum moisture content of 10% for both grades of fish meal. Keeping moisture low is critical for storage stability. Fish meal with moisture above 10% becomes highly susceptible to microbial growth, mould development, and spoilage. As noted by the IFFO, after drying and cooling in a typical production facility, fish meal reaches approximately 10% moisture – a level that will not support microbial growth under normal storage conditions.

Crude fat content 🔗

Fat content in fish meal is capped at 10% maximum under BIS standards. While the omega-3 fatty acids (EPA and DHA) present in fish oil are nutritionally beneficial, excessive residual fat creates problems. High fat levels increase the risk of oxidative rancidity during storage, which degrades the nutritional value of the meal and produces harmful by-products. The fat level in the final product depends on the species of fish used – oily species naturally produce higher-fat meal – and how effectively oil is removed during pressing.

Acid-insoluble ash (sand content) 🔗

AIA is a direct indicator of contamination during processing. It measures the amount of sand, silica, and other insoluble minerals present in the fish meal. The BIS allows a maximum of 3% AIA for Grade I and 5% for Grade II. High AIA values suggest poor handling of raw materials, inadequate cleaning of fish before processing, or contamination during drying and storage. Excessive sand content dilutes protein quality and can cause physical irritation to the digestive tract of animals.

Salt (sodium chloride) content 🔗

Salt levels indicate how much seawater residue or added salt remains in the product. BIS limits NaCl to 4% for Grade I and 5% for Grade II. Excessive salt in animal feed can disrupt electrolyte balance, increase water intake, and reduce feed palatability. Fish meal produced from well-drained, fresh raw material typically has lower salt levels than meal made from older, poorly handled catch.

Ammoniacal nitrogen 🔗

Ammoniacal nitrogen is capped at 0.5% for both grades. This parameter reflects the degree of protein breakdown or spoilage in the raw material before processing. Higher ammoniacal nitrogen values indicate that the fish had already started decomposing before it was turned into meal, which compromises both the nutritional value and safety of the final product.

The role of raw material freshness 🔗

Freshness of the incoming fish is arguably the single most important factor determining fish meal quality. As the IFFO notes, minimising the time between catching and processing – along with proper refrigeration – is essential to prevent spoilage. When fish decomposes, proteins break down into free amino acids, biogenic amines (like histamine and cadaverine), and volatile nitrogen compounds.

Total volatile nitrogen (TVN) is a widely used freshness indicator in the fish meal industry. Research published in Aquaculture journal demonstrated that fish meal produced from fresh raw material (TVN below 30 mg N/100 g) consistently outperformed meal from stale raw material in animal feeding trials, particularly for shrimp and young fish. Higher TVN values in the raw material led to elevated biogenic amine levels in the finished meal, reducing palatability and growth performance in sensitive species.

Many IFFO member factories now link fishermen’s payments to the freshness of their catch, measured by TVN at the point of unloading. This simple economic incentive encourages fishers to use refrigerated seawater and land their catch quickly.

How the manufacturing process affects quality 🔗

Even the freshest fish can yield poor-quality meal if the manufacturing process is not properly controlled. Fish meal production involves four main steps: cooking, pressing, drying, and milling. Each step has the potential to either preserve or damage nutritional quality.

Cooking 🔗

Fish is typically cooked at 85-90°C to coagulate protein and release oil. This step also destroys harmful microorganisms. However, overcooking at excessively high temperatures can denature proteins and reduce their digestibility. The IFFO recommends gentle cooking at 90°C or under to maintain nutritional value, particularly digestibility.

Pressing 🔗

After cooking, a screw press separates the solid press-cake from the liquid (which contains oil and stickwater). Effective pressing removes excess water and oil, concentrating the protein. However, over-pressing can strip away some beneficial oils and water-soluble nutrients. The liquid fraction is further processed: oil is separated by centrifuge, and the stickwater is concentrated and added back to the press-cake before drying.

Drying 🔗

Drying is the final critical step. The product must reach the target moisture of around 10% without being overheated. There are two main approaches: direct drying (using hot air or flame) and indirect drying (using steam-heated coils or vacuum systems). Indirect and low-temperature drying methods produce what is known as “LT” or “special” fish meal, which has higher protein digestibility and lower amine levels compared to standard FAQ (fair average quality) meal dried with direct flame. According to IFFO data, standard fish meal typically contains 64-67% crude protein, while special products made with gentler drying can achieve 68-72% protein with lower histamine levels.

Proper storage to maintain quality 🔗

Once fish meal is produced, maintaining its quality during storage and transport is essential. Fish meal is rich in polyunsaturated fatty acids (PUFAs), which are highly susceptible to oxidative rancidity. Oxidation not only destroys beneficial omega-3 fatty acids but also produces peroxides and aldehydes that can be toxic to animals.

To prevent this, antioxidants are commonly added immediately after drying. Ethoxyquin has historically been the antioxidant of choice in the fish meal industry due to its effectiveness and low cost. A study published in Translational Animal Science found that fish meal treated with ethoxyquin showed significantly less protein oxidation compared to untreated meal when stored at 20°C for six months. However, ethoxyquin has faced regulatory scrutiny – the European Union phased out its authorization in 2020 due to insufficient safety data on some of its transformation products. The industry is now actively exploring alternative antioxidants, including mixed tocopherols (natural vitamin E) and BHT.

Beyond antioxidants, proper storage also means protecting fish meal from moisture uptake, temperature extremes, and pest contamination. Storage facilities need good ventilation to prevent condensation, which can create hot spots leading to spontaneous combustion – a real risk with high-fat fish meal.

International quality benchmarks 🔗

While BIS standards govern the Indian market, fish meal traded globally must often meet additional international benchmarks. The IFFO promotes quality assurance schemes like HACCP (Hazard Analysis Critical Control Points), which requires producers to identify, monitor, and document critical control points throughout production. Parameters like product temperature, moisture content, and microbial counts are regularly checked.

In the European Union, fish meal producers are encouraged to adopt the International Feed Standard Alliance (IFSA) quality assurance framework, which covers everything from raw material sourcing through factory processing, storage, and transport to the end user. Fish meal intended for the EU market must also be free of land animal material and meet strict limits on contaminants such as dioxins, PCBs, and heavy metals.

For buyers, understanding these standards helps in making informed sourcing decisions. A fish meal that meets both BIS Grade I specifications and carries IFFO or HACCP certification provides a higher degree of assurance regarding protein quality, freshness, and safety.

Practical tips for evaluating fish meal quality 🔗

Whether you’re a feed manufacturer, aquaculture farmer, or livestock producer, here are some practical indicators to assess fish meal quality:

Colour: Good fish meal is typically light to medium brown. Very dark meal may indicate overheating during drying, which reduces protein digestibility. Very light meal might have excessive ash from bone inclusion.

Smell: Fresh, properly processed fish meal has a mild, pleasant fishy odour. A sharp, ammoniacal smell suggests spoiled raw material, while a rancid odour points to fat oxidation.

Texture: The meal should be uniformly ground without large lumps or foreign particles. Gritty texture can indicate high sand or ash contamination.

Laboratory testing: For any significant purchase, always request a certificate of analysis showing protein content (Kjeldahl method), moisture, fat, ash, AIA, salt, and ideally TVN or histamine values. These numbers tell you far more than visual inspection alone.

The bigger picture: why standards drive industry improvement 🔗

Quality standards do more than just classify fish meal into grades. They drive continuous improvement across the entire value chain. When fishermen know their payment depends on freshness scores, they invest in better onboard refrigeration. When processors know their product will be tested against BIS or IFFO benchmarks, they invest in temperature-controlled drying systems and regular laboratory testing. When buyers insist on certified fish meal, they push the entire market toward higher quality.

In India, with the growing aquaculture sector and rising demand for quality animal feed, adhering to BIS standards for fish meal is becoming increasingly important. The BIS framework provides a solid foundation, but awareness of international best practices – particularly around freshness testing, process temperature control, and antioxidant management – can help Indian producers compete in global markets.

What do you think? How important is it for Indian fish meal producers to align with international quality standards beyond the BIS framework? And as a farmer or feed buyer, what quality parameter do you consider most critical when purchasing fish meal – protein content, freshness, or something else entirely?

References

1. https://www.bis.gov.in/wp-content/uploads/2022/01/Indian-Standards-on-Dairy-Animal-Husbandry-updated_compressed.pdf
2. https://www.iffo.com/quality-control-and-quality-assurance
3. https://www.feedipedia.org/node/208
4. https://www.iffo.com/how-are-marine-ingredients-produced
5. https://www.sciencedirect.com/science/article/abs/pii/S0044848698002294
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC7743793/
7. https://www.tandfonline.com/doi/full/10.1081/JFP-120005797