While the basic processes of grinding, mixing, and pelleting have remained consistent over time within the feed industry, there is a growing emphasis being placed on improved precision and efficiency in these manufacturing processes while providing a high quality product. This push for advancement is essential in helping to address the major challenges facing today’s feed industry. Many of the current issues revolve around ingredients, or more specifically by-product ingredients from food processors, renders, and bio-fuels industries. Challenges in sourcing consistent high-quality ingredients are further compounded by facility design and its ability to adapt to changing diet formulations. Thus, equipment manufactures and feed manufacturing operations are continuously looking for solutions that enhance and improve the current manufacturing process. Resolutions can be difficult as feed mills initially designed for longevity have minimum flexibility in process flow, leading to difficulties in adapting new technologies. New construction allows for the greatest opportunity to incorporate new feed manufacturing technologies; though, the cost of a new feed mill can be a large expense that companies are not willing to accrue. However, development of automation systems, rapid detection of ingredient quality, and modifications to equipment used for grinding and pelleting can be adapted to help improve efficiency and precision to produce a high quality product.
When taking into consideration the feed manufacturing process and the cost associated with feed formulation, the greatest opportunity for improvement may be in the area of data management and analysis. In response to new government regulations and consumer demands for traceability, many mills have adapted automation systems. This has led to improvements in precision, ingredient lot tracing, utilization of bar code readers for ingredient additions, and summarization of process data (Stark, 2014). Moreover, programmable logic computer (PLC) and variable frequency drive (VFD) controllers are now used to increase the precision of ingredient additions during the batching process. Determining if the correct amount of each ingredient is being added to each batch of feed is one way to optimize one’s quality assurance program. Automation systems also allow feed mill managers to perform statistical process control (SPC) analysis on individual ingredients and bins each time a batch of feed is manufactured to ensure targets are being met over time. The cost of not adding enough ingredients in an integrated and commercial feed mill will result in poor animal performance and loss of customers, respectively. Whereas the over addition of ingredients results in ingredient shrink. The data generated from SPC can also be used to help make decisions based on equipment updates to improve accuracy and precision of major and minor ingredients. Feed mills continue to get larger with more processes being monitored and controlled through the automation system, increasing the amount of available data to managers wishing to initiate or monitor process changes.
Precise feed manufacturing is an essential step in optimizing animal performance. In order to ensure that diets are manufactured to meet the formulation specifications, one must know the nutrient composition of the ingredients prior to use. Therefore, it is beneficial to quantify ingredient quality prior to receiving. This becomes more important with the use of ingredients that are highly variable in nutrient content or quality, such as by-products from the food industry. The challenge is the limited amount of time available to characterize those ingredients based on nutrient composition upon receiving. However, new technologies are emerging to help reduce the time needed to gain results. Near infrared spectroscopy (NIR) in-line technology has the potential to transform how ingredient quality is evaluated in a facility by quantifying the moisture, protein, fiber, and fat content of ingredients as they pass across in-line probes (Stark, 2014). Additional advantages of NIR include minimal sample preparation, high precision, low sample cost, and no chemicals or waste (Eubanks, 2013). Although quantifying these components is pertinent to understanding the quality of ingredients, it does not bring economic value without the appropriate application. The economic advantages in diet formulation are based on the company’s ability to develop prediction equations to estimate energy (ME or NE) and amino acid composition of ingredients and then separate ingredients based on their nutrient values within least cost formulation (Stark and Jones, 2015).
In addition to improvements in ingredient evaluation methods, there have also been some significant advancements in how raw ingredients are ground. Modifications of both roller mills and hammermills have improved their efficiencies. Traditionally, the operating costs (electricity, labor, and maintenance) and capital investment should be taken into consideration when selecting the type of grinder to purchase for the feed mill (Heimann, 2014). The differences between grinding systems, however, has been minimized through technological advancement. For instance, one of the initial disadvantages of using a roller mill for grinding is the additional maintenance required; however, automation systems have since been developed to automatically adjusts rolls to feed at optimum speed. Keeping rolls in tram and parallel help to produce a consistent finished product with minimal wear on the machine. In addition, the automation can alert you to maintenance and operation issues before causing downtime. Alternatively, when using a hammermill to grind grains, there are several factors which can affect the final particle size achieved. Traditionally, the most common method of changing the particle size is to exchange the size of screens for either a smaller or larger hole diameter. However, screen changes lead to increased down time and loss of production within a facility. An alternative solution to reducing particle size without changing screens is to adjust the hammer tip speed (Saensukjaroenphon et al. 2017). Because tip speed is a function of hammermill diameter and motor speed, it is necessary to have a VFD on the hammermill motor to adjust tip speed. The VFD allows the operator to adjust hammer tip speed while requiring minimum idle time. These two advancements can be applied to help improve the grinding process.
Pelleting diets for swine and poultry have proven to be beneficial for the producer by improving animal performance and handling characteristics. The pelleting process allows the feed mill to agglomerate ingredients of different particle sizes, densities, and flow characteristics. This provides flexibility in the nutritionist’s use of ingredients allowing them to incorporate low cost ingredients with poor flow characteristics into finished feed formulations. However, these changes in diet formulations can lead to complications in the pelleting process or adjustments that need to be made to accommodate different types of diets. New technologies, such as remote roll adjustment and roll speed indication, have been adopted to help reduce these complications. This allows for adjustment of the gap between the roller and die surface during the pelleting process. Being able to adjust the rolls without stopping the machine and opening the pellet chamber reduces the amount of downtime and improves safety of the pelleting process. In addition, roll gap settings can be preset and minimum die/roll clearance can be set to minimize or prevent metal-to-metal contact reducing die wear and increasing longevity.
Feed manufactures will have to continue to provide a safe high quality feed supply while continuing to increase traceability. This challenge will increase as the feed industry is forced to rely on greater inclusions of non-traditional energy and protein by-product sources, as more cereal grains are diverted to human food production. The feed industry must continue to evaluate new equipment and manufacturing techniques that make efficient use of new by-products in animal feed production systems (Schoeff, et al. 2005). New technologies and greater automation of the feed manufacturing process as described herein will help the animal feed industry meet these demands.
We also suggest you to read our previous article titled "Process in the compound feed production".