Fish meal is an essential ingredient in animal feed that provides important nutritional benefits In this article, we’ll take a deep dive into everything you need to know about fish meal – what it is, how it’s made, why it’s used in animal feed, and some of the controversies surrounding its production
What is Fish Meal?
Fish meal is a commercial product made by cooking, pressing, drying and grinding whole fish or fish waste into a powder or cake It’s commonly used as a protein supplement in feed for poultry, pigs, aquaculture and pets.
The fish used to produce fish meal are small, bony, oily fish that are not generally consumed by humans directly, such as anchovies, menhaden, sardines, herring, capelin and sand eel. Approximately 4-5 tons of fish are needed to manufacture 1 ton of fish meal.
Fish meal typically contains between 60-72% crude protein by weight. It’s rich in amino acids, vitamins and minerals that are essential for animal growth and health. The high protein content and palatability make it a cost-effective addition to animal feeds.
How is Fish Meal Produced?
The manufacturing process for fish meal generally involves the following steps:
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Cooking: The fish are cooked at high temperatures using steam to liquefy the proteins and release the water and oil. This facilitates pressing.
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Pressing: The cooked fish paste is pressed to remove water and oil, reducing the moisture content from around 70% to 50%.
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Drying: The pressed cakes are dried by tumbling in a heated drum to further reduce moisture. This preserves the meal and prevents spoilage.
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Grinding: The dried meal is then ground into a uniform powder or pellet.
Antioxidants are often added to prevent the high-fat meal from oxidizing and potentially combusting during storage and transport. Ethoxyquin is a common antioxidant used for this purpose.
Why is Fish Meal Used in Animal Feed?
There are several key reasons fish meal is such a valuable ingredient in animal feed:
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High in protein: Fish meal contains 60-72% protein, making it an excellent source of this essential macronutrient. The protein has a well-balanced amino acid profile.
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Highly digestible: The proteins in fish meal are more digestible for animals compared to plant-based proteins. Digestibility ranges from 85-95%.
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Palatability: Animals find the flavor of fish meal very palatable which stimulates feeding. This supports growth.
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Supports immune function: Fish meal is rich in amino acids like arginine that support immune function and disease resistance in animals.
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Cost effective: Despite higher prices compared to crops like soybean meal, the nutritional benefits make fish meal a cost-effective addition to feed.
Fish meal helps meet the protein and amino acid requirements of poultry, pigs, farmed fish and other animals in a digestible and bioavailable form. This optimizes growth, health and production efficiency.
What Fish Species are Used in Fish Meal?
The most common fish species used to produce fish meal include:
- Anchovies (Peru, Chile)
- Menhaden (US)
- Capelin (Iceland, Norway)
- Sand eel, sprat (Denmark)
- Pilchard, anchovies (South Africa)
- Herring, blue whiting (Norway)
- Sardines, mackerel (Japan)
These small, oil-rich fish are caught specifically for the production of fish meal and oil. Approximately 20% of all fish captured globally is reduced into fish meal and oil.
Anchovies and menhaden alone account for over 35% of fish meal production. Peru and China lead the world, together producing over 50% of all fish meal.
Environmental Impacts of Fish Meal Production
While fish meal provides important nutrients for farm animals, its large-scale production raises environmental concerns including:
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Overfishing: High demand for fish meal promotes overfishing of small pelagic species like anchovies. This puts pressure on marine ecosystems.
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Bycatch: Fish meal made from bycatch contributes to depletion of other fish stocks impacting biodiversity.
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Sustainability: Fish stocks used for meal/oil must be managed carefully to avoid overexploitation and collapse.
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Water pollution: Effluent discharged from fish processing plants contributes to ocean pollution if not treated properly.
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Food security: Fish like anchovies used for meal could alternatively help feed people directly in some regions.
More sustainable fishery practices, use of fish waste byproducts and alternative protein sources in feed could help reduce the environmental footprint of fish meal.
Controversies and Changes in the Fish Meal Industry
The large fish meal industry has attracted controversy over the years related to sustainability and environmental impact. Some of the key issues have included:
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Overfishing of anchovies and other fish stocks used for meal production.
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Lack of quotas and catch limits resulting in overexploitation.
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Use of edible fish species like herring and mackerel for meal rather than direct human consumption.
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High levels of bycatch contributing to fish meal.
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Pollution from fish processing plants.
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Lack of transparency in some regions regarding fish catch volumes and practices.
In response, the industry has made some positive steps including:
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Greater use of fishery byproducts to produce meal to reduce pressure on targeted fish stocks.
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Increased reliance on trimmings and offcuts from seafood processing for human consumption.
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Development of more sustainable fishery practices through quotas and stock assessments.
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Exploring alternative proteins sources such as soy, insects, algae and yeast to replace a portion of fish meal used in feeds.
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Research into fish meal substitutes and ways to strategically use lower inclusion rates while maintaining nutritional benefits.
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Improved effluent treatment and waste management practices to reduce pollution.
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Increased focus on responsible sourcing policies and transparency.
While still not perfect, the fish meal industry has made progress in efforts to increase sustainability and reduce the environmental footprint of fish meal production. More work is still needed.
The Takeaway on Fish Meal
Fish meal is an incredibly nutritious animal feed ingredient that provides a concentrated source of digestible protein and healthy fats. However, we must also be mindful of the potential environmental impacts of large-scale fish meal production such as overfishing, bycatch waste, and pollution. The industry continues to make improvements but finding the balance between the nutritional benefits of fish meal and long-term marine sustainability remains an ongoing challenge.
How is fish meal used?
Before about 1910, fish meal was mostly used as fertilizer in the UK. Since then, its high nutritional value has been better used to feed animals. People in the UK want fish meal much more than they want fish to eat directly, so a lot of fish meal is brought into the UK from other countries. The pork and chicken industries that make a lot of bacon and eggs at low prices would not be able to stay in business without using a lot of high-protein animal foods like fish meal. Animals like pigs and chickens usually eat about 10% of their food as fish meal. 10% is the most meal that can contain 10% fat, because giving an animal more than 1% fish oil may change the taste of its meat. A lot of what is made in the UK is white fish meal, which has so little fat that there is no risk of taint. Fish meals with an extremely low fat content are sometimes made for certain specialized purposes.
Other uses of fish meal include the feeding of mink, farmed fish, dogs, cats and cattle. Very small amounts of specially processed meals have been used to make foods for people, and fish meal is also used to make some antibiotics for the pharmaceutical industry.
Composition and nutritionalvalue
Before looking at what’s in the finished meal, it’s interesting to see what’s in the products that come before it. Figure 2 displays the make-up of the material at each step of the process. It is based on the idea that raw fish is mostly water, with 18% solids and 12% fat. It can be seen that more drying occurs in the evaporators than in the dryer. The composition of the intermediate products in this example is as follows:
|
water |
solids |
fat |
|
|
material |
% |
% |
% |
|
raw fish |
70 |
18 |
12 |
|
press cake |
53 |
44 |
3 |
|
press liquor |
78 |
6 |
16 |
|
dilute stickwater |
95 |
5 |
<1 |
|
conc. stickwater |
65 |
33 |
2 |
|
fish meal |
9 |
85 |
6 |
Figure 2 shows that oily fish with the assumed composition would yield 21% whole meal. In reality, there may be some processing losses that make the actual yield a little lower. For instance, raw material that is waiting to be cooked will lose some drip as it goes bad. Since the lost liquor has protein in it, yield will go down when raw material is held up for a long time. The extent of this loss varies from species to species.
The type of process and the type of raw material affect what the final product is made of. In general, a meal made from fatty fish like herring might have about 71% protein, 9% fat, 8% water, and 12% minerals. On the other hand, a meal made mostly from white fish and white fish offal and dried to the same degree will have about 66% protein, 5% fat, 8% water, and 21% minerals.
Fish meal is valuable not only for the quantity but also the quality of its protein. This means that the amino acids that make up the protein are present in the right amounts for people or animals to eat. The amino acid composition of typical samples of herring meal and white fish meal might be:
|
herring meal |
white fish meal |
|
|
amino acid |
g/100 g protein |
g/100 g protein |
|
lysine |
7·7 |
6·9 |
|
methionine |
2·9 |
2·6 |
|
tryptophan |
1·2 |
0·9 |
|
histidine |
2·4 |
2·0 |
|
arginine |
5·8 |
6·4 |
|
threonine |
4·3 |
3·9 |
|
valine |
5·4 |
4·5 |
|
isoleucine |
4·5 |
3·7 |
|
leucine |
7·5 |
6·5 |
|
phenylalanine |
3·9 |
3·3 |
|
cystine |
1·0 |
0·9 |
|
tyrosine |
3·1 |
2·6 |
|
aspartic acid |
9·1 |
8·5 |
|
serine |
3·8 |
4·8 |
|
glutamic acid |
12·8 |
12·8 |
|
proline |
4·2 |
5·3 |
|
glycine |
6·0 |
9.9 |
|
alanine |
6·3 |
6·3 |
In many feeding tests, animals that were fed diets with similar amino acid profiles to fish meal did not grow as well as those that were fed fish meal itself. This has led to the idea that fish meal contains an unknown growth factor, which is sometimes written as UGF. But no one has ever been able to separate this ingredient. In other feeding tests, carefully supplemented vegetable protein diets have given the same results as fish meal. The problem might be solved by the fact that fish meal has so many healthy nutrients that it can make up for anything that is missing in the diet. So, UGF’s property might be due to proper nutrition rather than the presence of an unknown, as of now unidentified substance that helps plants grow.
What is Fish Meal?
What is fish meal used for?
Fish meal is now primarily used as a protein supplement in compound feed. As of 2010, about 56% of fish meal was used to feed farmed fish, about 20% was used in pig feed, about 12% in poultry feed, and about 12% in other uses, which included fertilizer.
Is basa fish a good meal for one night in the week?
Yes, basa fish is a good option for a meal once a week, as like other white fish, it is high in protein and low in calories. It also contains small amounts of healthy omega-3 fatty acids. Eating lean fish like basa has been linked to longevity and a reduced risk of heart disease.
What is fish meal & fish oil?
Fish oil is a coproduct with fish meal during processing. Usual yields of fish meal and fish oil from live fish ( IFFO, 2017) are 22.5% and 4.8%, respectively, or a fish meal to fish oil recovery ratio of 4.69. The reduction fishery of 17.7 Mt in 2018 yielded an estimated 3.98 Mt fish meal and 0.85 Mt fish oil.
What is fish meal made of?
C.E. Boyd, in Feed and Feeding Practices in Aquaculture, 2015 Fish meal is made from small, pelagic, oceanic fish such as menhaden, herring, anchovies, and sardines. The small fish are pulverized, and the oil and water are pressed out. The remaining solids are cooked and pulverized into a meal.