Monday, July 15, 2024
General Agriculture

Classification of Feeding Stuff and Feed Supplements: Protein Supplements

A supplement feed or feed mixture including protein supplements is used to improve the nutritional value of the ration complementing the nutrients in the base feed. A supplement is rich in one or more of protein, energy, vitamins or minerals, and, in combination with the base feeds, produces a more complete feed.

Feed supplements are added to the main feed to supply one or more nutrients which might be lacking in the main feed. A mixed protein supplement is, by convention, a mixture of feeds which carries 30% or more of protein. Single feeds containing 20% or more of protein are included in this group.

1. Animal Protein

In general, animal-based protein feedstuffs are excellent sources of protein. In comparison to plant-based protein feedstuffs, the amino acid profiles of the animal-based protein feedstuffs more closely match the amino acid profiles required by the animal.

One potential issue with animal-based protein feedstuffs is quality. Protein quality will vary by source and also by processing method. The cost is also greater for animal-based protein feedstuffs compared to plant-based protein feedstuffs.

In the future, the use of animal-based proteins may decline as a result of quality issues, cost, the availability of synthetic amino acids and vitamins once only available via animal-based protein feeds, and the improved protein quality of plant-based protein feedstuffs.

The protein feeds of animal origin are primarily derived as end products of the meat packing, dairy processing, and marine industries. The most important of these are meat meal, bonemeal, blood meal, feather meal, dried milk, and fish meal. The milk products are the highest quality of the end products and generally the most expensive

2. Plant Protein

The protein feeds of plant origin are primarily derived as products of the extraction of the oil from a group of seeds referred to as oilseeds because of their high fat content. These protein sources are thus referred to as oilseed meals.

The most important of these sources are soybeans and cottonseed. The protein content is generally at least 40% and highly digestible and protein quality is usually good.

3. Non-protein Nitrogen (NPN)

The NPN sources generally refer to urea and other similar products. Urea and similar products must be used with functional ruminants only and then, very carefully.

Because ruminants can convert the poorer quality proteins to higher quality microbial protein, an effective cost-reduction strategy is to feed the NPN sources and avoid the higher quality, and thus more expensive protein supplements.

Some common protein supplements include: blood meal, brewers dried grain, canola meal, casein (dried), cottonseed meal, feather meal, fish meal, meat and bonemeal, milk, whole dried; soybean meal.

Read Also: Classification of Feeding Stuff and Feed Supplements: Energy Feeds

Animal Protein Source

1. Fish meal

Fishmeal is made from dried ground, whole fish, or fish cuts, offals with or without oil extraction. There are various brands of fish meal but the commonest are those with high oil including herring, menhaden, salmon and low white fish.

It is a very common animal protein feed ingredient in use. It is a byproduct of fish industry. It is usually made from whole fish.

However, fish offals of high quality could also be used. Local fish meal is lower in its protein content than the imported fish meal.

Crude protein content of fish meal may vary from 55 and 77% depending on the fish type use and extent of oil extraction. Calcium (3-6%) and phosphorus (1.5 – 3%) contents and micro mineral content is high (3-6% and 1.5 – 3%) respectively.

Fish meal is low in fat soluble vitamin because they are extracted along with the oil. It is however, high in vitamin B complex vitamins especially vitamin B12.

Protein Supplements

Its biological value is very high and usually varies from 60-80%. It is a good source of sulphur amino acid (methionine is about 1.8%). Its lysine content is about 4.5%.

Fish meal must be properly stored because of its residual oil causing rancidity.

Limitation of Fish Meal

It is usually used at a level between 0 – 5% for economic reasons.

High levels of inclusion may make animal go off feed.

Fish meal flavor may also be imparted to the carcass at higher level of inclusion.

Fish meal must be properly stored because of its residual oil. There is also an underlying concern over dioxin levels in fishmeals.

2. Blood meal

It is a slaughter‘s house by products. It is prepared from fresh and clean animal blood free of all extraneous materials such as stomach content, hair and urine. The water in the blood is usually removed by parboiling.

It is parboiled or mechanically dewatered the resulted semi solid blood mass is rapidly dried and ground to obtain meal. It is high in protein (80-88%). It is an excellent source of lysine if properly prepared. It is also rich in leucine but is low in isoleucine, ash calcium and phosphorous.

The fiber content in blood meal is low. Blood meal is also low in minerals, with the exception of iron. It can partly replace fish meal in starter diets for broiler chicks and turkey but can replace all the fish meal in broiler finisher.

The Nutritional value is influenced by processing. Flash drying produces the most consistent product. The crude protein content of blood meal is 80-85% on an as-fed basis.


Badly processed blood meal may expose animal to the attack of salmonella organisms or create problems of flies.

Its amino acid content is not well balanced. It is low in sulphur containing amino acids.

Its biological value is low about 19%.

It is not usually utilized above 5% level.

Higher levels make animal go off feed.

Overheating reduces lysine availability of protein is less digestible.

3. Meat and Bone Meal

It is the rendered product from animal (especially mammals) tissues including bone. It excludes blood hair, hoof horn, hide trimmings, manure, stomach and rumen content. It contains about 50% CP and it is high in fat and ash.

The protein quality is variable depending on the quality of meat and amount of extraneous material. It is a good source of lysine, calcium and phosphorous but it is deficient in methionine, cystine and tryptophan.


Excessive processing temperature may reduce lysine availability.

Too high levels of inclusion may result in undesirably high levels of calcium and phosphorous.

4. Meat Meal (Meat Scrap)

It is the rendered products from animal (especially mammal) tissue. It excludes bone, blood, hair, hoof, horn, hide trimmings, manure stomach and rumen content. It is similar to meat and bone meal except that it is low in calcium and phosphorous.

It is classified as meat and bone meal. It is used at about 7-10 % dietary inclusion level. Meat meal is virtually non-existent in some countries as virtually all parts of the animals are consumed

5. Meat and Bone Meal Tankage

It is similar to meat and some meal except that it may contain blood or blood meal. Meat meal/tankage and meat and bone meal/tankage are classified based on the phosphorus content. Meals containing greater than 4.4% phosphorus are classified as meat and bone meal/tankage.

Tankages are classified according to the inclusion of dried blood, the labels are required to state nutrient content including minimum crude protein, minimum crude fat, maximum crude fiber, minimum phosphorus, and minimum and maximum calcium.

The crude protein contents of the various meals and tankages range from 45-60% crude protein on an as-fed basis. The protein qualities of the various products are rated as good to excellent.

The crude protein is digestible and are a good energy source because of the fat content. The products are also a good source of minerals such as calcium at 6-10% and phosphorus at 3-5%. Meat and bone products are a good source of riboflavin, niacin, and vitamin B12.


Meat and bone products are relatively unpalatable.

Meat and bone products contain a number of anti-nutritional factors.

Meat and bone products can potentially cause a calcium and phosphorus imbalance.

Improper processing, including inadequate heat-sterilization, can lead to contamination of the products by microorganisms.

Improper processing contributed to the transfer of transmissible spongiform encephalopathies (TSE). The most publicized transfer was the transfer across species to cattle. Bovine spongiform encephalopathy (BSE), also referred to as ―Mad Cow Disease

6. Poultry By-Product Meal

It consists of the ground, dried, rendered parts of the carcass of slaughtered poultry such as heads, feet offal, undeveloped eggs and intestine.

Feathers are not included. It is an excellent source of protein (about 55% CP). It is rich in lysine, tryptophan, calcium and phosphorous.

It is used at about 7-10 % dietary inclusion level. Poultry by-product meal should be used in combination with other protein sources

7. Feather and Hair Meals

Feather and hair are not digestible however, processing of feathers significantly improves nutritional value. Commercially available feather and hair meals are often referred to as hydrolysed feather and hair meal.

This is obtained by pressure streaming undecomposed clean feathers from slaughtered poultry. Excessive heat may destroy cysteine and lysine. The crude protein content is 85-90% on an as-fed basis.

Hydrolyzed poultry feathers are low in methionine, lysine, histidine, and tryptophan. Hydrolysed feather is about 75% digestible. Hydrolysed feather meal is high in cystine and threonine but deficient in lysine, methionine, histidine and tryptophan.

For monogastrics, hydrolyzed poultry feathers are fed in combination with complementary protein feeds. Hydrolyzed poultry feathers are also relatively unpalatable. The amount fed to monogastric animals should be limited to 5% of the ration.

8. Dried Poultry Manure

Dried Poultry Manure is dried poultry excreta. Its chemical contents may vary depending on the source and age of the birds from which manure is obtained.

The protein content is between 25 and 29% CP, One-third of the protein is true protein and two-thirds of the protein is non-protein nitrogen compounds.

Fat content is 1.5 – 2.5% and fibre 14 – 20%. Lysine content is 0.3 – 0.5%, methionine 0.10 and 0.15%. Dried poultry manure is used in ruminant and mongastric animal feeding.

9. Hatching Waste

This is a mixture of egg and shells, infertile and unhatched eggs curled chicken that are cooked, dried and ground prior to use.

Rendered Animal Products: Meat and bone meal, a long-time traditional ingredient and rich source of amino acids and minerals in livestock feeds worldwide, is banned in the European Union.

This is due to the bovine spongiform encephalopathy (BSE) crisis and the link to the new variant Creutzfeldt – Jakob disease (vCJD) in humans

10. Miscellaneous Sources of Protein

a. Insect Meals

They include larva of insects, whole insects and earthworm for example edible grasshopper Black Soldier Fly, the yellow mealworm, housefly, house cricket, defatted silkworm they can replace plant protein or parts of the fishmeal used in the diet.

The crude protein of insect meal especially the larva is between 55-70% however their use in animal feed is prohibited in some countries due to safety concern.

b. Leaf Protein Concentrate

Plant protein contains fair amounts of protein. The protein can be concentrated by crushing and disintegrating the leaves or by precipitating protein concentrate from the leaf juice with the aid of heat or acid.

The concentrate so formed may contain up to 60% protein. It has been examined as a human or animal food source, because it is potentially the cheapest, most abundant source of available protein

c. Single Cell Protein (SCP)

Single Cell Protein refers to bacteria, yeast, fungi and algae (edible unicellular microorganisms). A biomass containing up to 50% or more can be produced from each of these microorganisms.

The biomass or protein extract from pure or mixed cultures of algae, yeasts, fungi or bacteria may be used as an ingredient or a substitute for protein-rich foods and is suitable for human consumption or as animal feeds.

Industrial agriculture is marked by high land use, biodiversity destruction, general environmental degradation and contributes to climate change by emission of a third of all greenhouse gases.

Production of SCP does not necessarily exhibit any of these serious drawbacks. As of today, SCP is commonly grown on agricultural waste products however, SCP may also be produced entirely independent of agricultural waste products through autotrophic growth.

Thanks to the high diversity of microbial metabolism, autotrophic SCP provides several different modes of growth, versatile options of nutrients recycling, and a substantially increased efficiency compared to crops.

d. Milk and milk by product

They include skimmed milk, condensed butter milk, dried whole milk. They are excellent source of protein but are usually too expensive to be included in the feed.

In summary, protein supplements are critical to growth and reproductive process in animals though are generally costly. However, plant proteins are been used more in recent times.

Feedstuff considered in this unit are high in protein, products from animal and plant have been enumerated.

Read Also: Knowing How Much For Copper Per Pound in Electrical Stores


Benadine Nonye is an agricultural consultant and a writer with several years of professional experience in the agriculture industry. - National Diploma in Agricultural Technology - Bachelor's Degree in Agricultural Science - Master's Degree in Science Education - PhD Student in Agricultural Economics and Environmental Policy... Visit My Websites On: 1. - Your Comprehensive Practical Agricultural Knowledge and Farmer’s Guide Website! 2. - For Effective Environmental Management through Proper Waste Management and Recycling Practices! Join Me On: Twitter: @benadinenonye - Instagram: benadinenonye - LinkedIn: benadinenonye - YouTube: Agric4Profits TV and WealthInWastes TV - Pinterest: BenadineNonye4u - Facebook: BenadineNonye

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