What is pelleting and what is a pellet?
Pelleting is the process of compressing materials through a die to form a cylindrical shape with a length that is usually 2 to 4 times its diameter. In fact, a pellet is a small, dense capsule. For many years, pelleting was considered an art, because the processes were not done with precise measurement and the results were uncertain, making it very difficult to make a quality product. Today, the science of animal feed technology has reached a point where, by knowing the characteristics of the feed (moisture, content, fiber, etc.) and using machines with precise measurement, it is done with certainty, not guesswork! Today there is no excuse for pellet making operators.
In the pelleting process, operators play an important role in the production of livestock and poultry feed. The smallest error in the work of the operators has a great impact on the profitability of the factory. They must recognize this responsibility and the great contribution they make to creating an efficient feed factory.
Therefore, pelleted feed is a collection of food materials needed by livestock and poultry, which has been compressed through a special process. Because of this compression, the required materials are transferred equally to the herd, which leads to uniform growth of the herd.
In general, the obvious advantages of pelleted feed or concentrate can be mentioned as follows:
- Reduce the dusty nature of feed
- Increase bulk density
- Improved flowability and gelatinization
- Improved palatability
- Reduce feed waste
- Increased consumption rate
- Less energy to eat
- Compaction of materials
- Elimination of pathogens
- Prevents feed separation
- Improved growth of livestock and poultry
- Reduced transportation costs
- Longer shelf life
- Reduced incidence of disease in livestock and poultry
- Uniform herd growth
The History of Animal Feed Pellets
For centuries, people fed their farm animals and chickens with hay and grain, sometimes using their own food scraps in raising animals. Everything changed with the Industrial Revolution. Horses, which were used for transportation, or war horses that also had to carry their own food, needed feeding stations. Heavy loads of feed made transportation difficult.
This led the British to develop the first compound feed as portable food for war horses. This food was similar to a large baked biscuit made of oats, peas, rye (black wheat), flaxseed, wheat or corn. According to nutritional experiments conducted by the Prussian army, 1.5 kg (33.8 lbs) of this compound horse feed could replace 5 kg (11 lbs) of barley.
Gradually, the focus on the food process, especially large flour mills, created an environmental problem in the country: these mills (which were easily built near water) dumped their waste into rivers and streams. On the other hand, wheat middlings have high nutritional value for animals along with their low density. Also, wheat middlings do not have good softness and have a dusty texture; therefore, eating it is not pleasant. As a result, the government banned waste disposal in water because wheat middlings contaminated the water.
In 1928, when Purina began pelleting waste from flour mills, it solved the need for efficient animal feed and the use of industrial food waste. Wheat middlings were mixed with animal by-products or soya cake, plus ground corn, mixed minerals and compressed into soft pellets.
How Pellets Are Made
In simple terms, pellets are physically made by compressing a feed mixture through a circular hole (called a die) in a piece of metal. If you drill a hole in a piece of metal, then place some feed on it, and run a machine over it, a pellet is made. If you drill many holes, you can make more pellets. If you drill the holes in a circle, place the wheel on the axle to allow it to move around and continuously place food in front of the rolling wheel, you will create a flat die press.
The challenge you face in this process is that the wheel or roller on the outside moves faster than the inside. This issue may affect the quality of the pellets and cause them to be pressed into an uneven shape. To improve the conditions, make the die into a ring with a roller inside. Initially, the rollers move and the rings just slide under it.
This technology is similar to flat die pellet making technology, except that in this method both the roller and the die are moving, which leads to better extrusion. Today, ring dies are the driving force, and the rollers slide inward.
To watch the video on how to make a platform, click here.
What are feed pellets made of?
To produce livestock and poultry feed, you first need a suitable diet formula, depending on the type and breed of the animal. First, with the help of specialists in this field and feed formulation software, you prepare a cost-effective diet with available materials. To learn about this process, you can read the article “How to Write Livestock and Poultry Feed Diets“.
Then, according to the formula of the pellet materials ration, which usually includes corn, soybean, micronutrients, poultry probiotic, livestock baking soda, and vitamins, etc., together with pelleting aids, are mixed together and finally made through a special process.
Article: Regarding the materials needed for feed pellets, you can read the article “The A to Z of Preparing Chicken Feed“.
The stages of feed pellet production
The production of pellets is a multi-step process in which the ground and mixed raw materials are subjected to pressure and heat and converted into small and uniform pieces. The following are the main stages of pellet production:
- Formulating the feed recipe: This is usually done by a nutritionist to ensure that the animal receives the nutrients it needs.
- Preparing raw materials: In this step, raw materials such as grains, oil cakes, nutritional supplements and other additives are ground and mixed in specific proportions according to the desired formulation.
- Weighing materials according to the instructions given: For this you need several scales. Large scales for coarser materials that make up more than 10% of the formulation. Small scales for micro-ingredients that make up less than 1% of the formulation.
- Grinding materials to specific sizes: The purpose of grinding raw materials in pellet production is to increase their contact surface and improve the digestibility of the feed. However, the optimal particle size for each raw material may be different. For this reason, in the industry, each material is first ground separately and then mixed together (pre-grinding).
- Mixing materials according to the formula: Use a ribbon blender or a paddle mixer that mixes 10 tons at a time. At this stage, you can add a pelleting aid and liquid-based materials.
- Transferring the mixture to the pellet press machine: Use a bucket elevator to carry the feed to the top of the mill and then pour it into the bucket above the pellet press.
- Steaming the mixture immediately before entering the press: This is done by adding steam directly to the horizontal mixing/transport chamber. The ventilation of heat and moisture to the feed softens it and makes it easier to press the pellets.
- Pelleting: The ventilated meal is poured into the press and pelleted there. Sometimes the pellets are cut by a knife on the outside of the mold to a specific length.
- Cooling the pellets: The hot pellets are poured into a counter-flow cooling tower, where air is blown through them in the opposite direction. This evaporative cooler returns the pellet to ambient temperature (between 3 and 5 degrees Celsius difference). At the same time, it removes the moisture that was added by the condensation of steam.
- Packaging the pelleted feed: The cooled pellets are moved for storage or packaging.
What is Pellet Quality and How Do You Measure It?
Pellet quality refers to a set of physical and nutritional characteristics that indicate how well the product can effectively meet the needs of livestock or poultry. In other words, a high-quality pellet, in addition to having good nutritional value, must have sufficient strength, proper size and shape, and high digestibility.
Pellets must travel long distances to reach poultry houses or farms. During these movements, the pellets must maintain their shape. Weak pellets separate or grind, creating dust or fine materials. Problems with weak pellets include the following:
- Separation of nutrients that leads to the loss of balance in the diet.
- The dust created can clog the nostrils of animals.
- In livestock farms, crushed pellets damage the robotic milking/feeding systems and prevent them from functioning properly.
What are Pelleting Aids?
In the livestock and poultry feed industry, “Pelleting Aids” are substances added to feed during the production process to improve the quality and durability of the pellets. These materials play an important role in improving the physical properties and sometimes the nutritional value of pellets. Farmers need to choose a feed that meets their nutritional and economic criteria. Some materials, such as fat and oil, are harmful to the durability and adhesion of pellets. To solve this problem, a little pelleting aid is used.
These materials are used for various reasons:
- Increased durability and hardness of pellets: One of the most important reasons for using Pelleting Aids is to increase the durability and hardness of pellets. This prevents the pellets from breaking down and turning into fine particles, known as “Fines,” during transportation, storage, and feeding. More durable pellets have less waste and prevent feed loss.
- Improved pellet quality: Pelleting Aids help improve the appearance, size, and uniformity of pellets. This makes it easier for livestock and poultry to consume the pellets and have a balanced diet.
- Increased production efficiency: The use of Pelleting Aids can facilitate the pellet production process and increase the efficiency of the feed production plant. By reducing friction between feed materials and pelleting machines, these materials also prevent wear and tear on equipment.
- Improved digestibility: Some Pelleting Aids can help improve the digestibility of feed and the absorption of nutrients by livestock and poultry. This is especially important for feeds that contain a lot of fiber.
- Reduced dust: Pelleting Aids can help reduce dust in feed, which is beneficial for the health of livestock and poultry, as well as the health of factory workers.
Why are Pelleting Aids Used?
Farmers should choose a feed that meets their nutritional and economic criteria. Some materials, such as fat, are harmful to the durability and adhesion of pellets. To solve this problem, a little pelleting aid is used.
What are the different types of Pelleting Aids?
Clays: These binders are usually used at a level of 1 to 2%. They are used as a filler and binder in feeds that are not dense. You can use them in feeds that are not nutritionally dense to create a filler as well as a binder.
Lignosulfonates/Lignin-based products: These are stable products derived from wood. These materials are usually processed between 0.5 and 1 percent and can withstand a wide range of temperatures and humidity.
Urea Formaldehyde (UF) or Polymethylene Urea (PMC): These binders are mainly used when it is desired that the pellets remain stable when immersed in water. The typical dose is between 0.5 and 1 percent. These thermoset polymers require heat for their bonds to become active.
Lubricants: These lubricants are typically formulated products, made up of at least two different materials. Their role is to ease the pelleting process, not necessarily to enhance the durability of the final pellets.
Scrubbers: These products are hard pieces of grit that can clean or polish the die holes as the feed passes through it. Sand or grit may be used.
What can you expect from Pelleting Aids?
Binders should reduce pellet fragility by 25 to 50 percent. If a binder is added to a feed whose pellet durability is 90.0, this durability should increase to 92.5 to 95.5. If the pellet durability is initially 80.0, it should increase to 85.0 to 90.0. The lower the initial pellet durability, the more significant the improvement in durability. However, the percentage reduction of fines, outside the pellet testing device or on the farm, should be in the range of 25 to 50%.
What are the costs and benefits of using Pelleting Aids?
Some pellet producers try to keep the costs of PELLETING AIDS down by limiting the dose. In some cases, the dose becomes so low that the PELLETING AIDS are not only no longer effective, but the small amount is also wasted.
Therefore, it is important to determine the most cost-effective dose for PELLETING AIDS in the system in which it is used.
For example, the most cost-effective dose for a lignosulfonate/lignin-based product may be 0.5%, which may reduce losses by 40%. If the dose is increased to 1.0%, the loss may be reduced by up to 55%. This is indeed an improvement, but it costs twice as much, while the increase in improvement is less than half. However, if this quality improvement causes the farmer or poultry farmer to buy these pellets due to the increased quality, the costs are covered and it is worth it. In addition to increased sales due to excellent quality, other benefits of using PELLETING AIDS include:
There is no longer a need to recover poor quality pellets from farms
Increased production rate
Ability to formulate with appropriate materials without losing pellet durability.
Making Pellets at Home
Many breeders believe that preparing livestock and poultry feed at home is more cost-effective. For this reason, they tend to prepare feed at home. The steps of preparing homemade pelleted feed are not much different from the industrial system. But it is very important to get help from a nutritionist for making homemade pellets. Be sure to be careful in preparing the materials. Use high-quality and quality materials. If possible, test the nutritional content of your feed to make sure it meets the required standards. Observing hygienic principles during the pellet feed production process is very important. Any contamination in the feed will jeopardize your breeding efficiency. You may even lose your herd.
According to the points that have been mentioned to you, you will act to prepare the steps in the manner mentioned above. Finally, for making homemade pellets, you need tools that we will name the equipment needed for pelleting here:
- Hammer mill or grinder: To crush grains and other materials into fine powder.
- Mixer: To fully combine all materials.
- Pellet mill: A device that converts feed into compressed balls. Small and home pellet mills are available in the market.
- Drying equipment: Optional, but can help reduce moisture if needed.
What factors affect the physical quality of pellets?
Undoubtedly, the materials that make up the pellets are the main factors in this process. Some of these materials must act as a binder to connect between the particles. Grinding the materials is also important; the particles must be able to pass through the holes. Also, the compression of the feed as it passes through the die is very important. Finally, the method of cooling the pellets and reducing moisture is important due to the bonding of the materials to each other and the strength of the pellets.
Methods for Measuring Pellet Quality
Various methods are used to measure pellet quality, some of which are mentioned below:
• Pellet Durability Index (PDI) test: In this test, the pellets are placed under specific conditions and their resistance to abrasion and breakage is measured.
- Measuring specific weight: The specific weight of the pellet indicates its density.
- Moisture test: The moisture content of the pellet is measured using special devices.
- Nutrient analysis: The amount of nutrients in the pellet is determined using laboratory methods.
Pellet Durability Index and Pellet Hardness
High-quality pellets are physically hard and durable. The Pellet Durability Index or Pellet Durability Test describes the pellet’s ability to resist damage and abrasion during transportation. This durability can be measured by pellet quality testing. To understand this, it is necessary to place 100 grams of pellets in a pneumatic tester under pressure for 30 to 60 seconds and then calculate the percentage of healthy pellets remaining. Another method is to place 500 grams of pellets in a rotating chamber and stir them for 10 minutes, then measure the percentage of remaining pellets. Pellet Hardness indicates resistance to pressure and applied forces.
How can we ensure pellet quality?
A high-quality pellet, in addition to having good nutritional value, must have sufficient strength, proper size and shape, and high digestibility. The characteristics of a good and high-quality pellet include the following:
- Proper strength and consistency: The pellet must be hard and resistant enough so that it does not break and crumble during transportation, storage and feeding.
- Size and shape: The size and shape of the pellet should match the type of livestock or poultry and their age. Also, the pellets should be uniform and the same size.
- Density: Denser pellets are usually of higher quality.
- Moisture: The moisture content of the pellet should be at an appropriate level to prevent the growth of fungi and bacteria.
- Digestibility: The pellet should be easily digested by livestock or poultry so that the nutrients in it are well absorbed.
- Pellet color: The color of the pellet is one of the factors in determining its quality. The color of livestock and poultry feed pellets is usually due to the natural color of the raw materials that make it up. For example, pellets containing more corn tend to be more yellow, and pellets containing soybean meal are light brown in color. The color of the pellet should be uniform and should not have dark or light spots. The presence of color spots can be a sign of mold or other problems.
- Pellet surface: The pellet should have a smooth, polished surface, and the absence of cracks and breaks in the pellet indicates its good quality.
- Pleasant odor: A high-quality livestock and poultry feed pellet usually has a mild and pleasant odor that is caused by the raw materials that make it up, such as grains, oil cakes and other additives. Livestock and poultry feed pellets should not have a strong and unpleasant odor. The presence of a strong odor can be a sign of spoilage of raw materials, the presence of mold or other problems. The smell of mold in livestock and poultry feed pellets is a sign of high humidity and the growth of fungi and can be harmful to livestock and poultry.
- Nutritional value: The pellet should contain sufficient amounts of nutrients needed by livestock or poultry.
Conclusion
Pelleted feed production improves work efficiency, reduces feed costs, and increases costs. Pellets are not only used in livestock concentrates, but are also produced for broiler and broiler feed. Preparing feed in a mash manner increases the consumption of livestock and poultry feed, as well as the work of workers. While pelleted feed reduces the animal’s sensitivity and is very useful for their digestion and absorption. Other advantages include easy transportation and its small size in the feed warehouse. All these factors go hand in hand to make pelleted feed an affordable food for livestock and poultry farmers.
