Position: New automation technology developments in feed processing and delivery have emerged over the past few years resulting in greater efficiency of production, feeds that more nearly meet the nutritional needs of farm animals, and the ability of managers to implement control over the vast amount of information flowing from automated processes. The most significant advancements have come on the “software” side of the industry with the adoption of modern management practices such as: continuous quality improvement, benchmarking, and HACCP programs.
Automatic Proportioning Systems
Current batching control system technology is quite good but is sometimes difficult to maintain. There is room for improvement in several areas.
On-line Reformation
Instrumentation is currently being tested that can measure chemical components such as protein, certain amino acids, fat, moisture fiber, and starch. It will be possible to reformulate feed on a nearly batch-tobatch basis and create feeds with a great deal of precision.
Automatic Weighing Accuracy
There are micro-ingredient systems available that use a loss-in-weight concept rather than net weighment into a single batching scale. This concept can be expanded to include ingredients received in tote bags or tanks.
Using loss-in-weight, it is possible to envision 10 or 15 weighments going on simultaneously. This will shorten the batching cycle and provide continuous inventory reports and more Automatic precision weighing than is currently possible. Batching cycles in the range of 1 to 1.5 minutes will be necessary to keep up with the short cycle mixers of the future.
Mixing
This is a very confusing area given the trends toward very large single mixers (12-15 ton) in new singlespecies feed mills. I do feel that there will be a place for small (2-4 ton), short cycle mixers because of the need for production flexibility and high hourly throughput. For example, a 3 ton mixer on a 1.5
minute cycle can produce 120 T/hr. This is possible even today and 1.0 minute cycles may be available in the future.
Pelleting and Other Hydro-Thermal Processes
The pelleting process will not be replaced within the foreseeable future; however, there will be innovations made that will result in improvements in both efficiency and pellet quality. Some innovations and options are currently available but are seldom retro-fitted into existing feed mills. Below is an outline of some current and future options for conditioning, pelleting, and cooling operations.
Conditioning-Time Controllers
There is no single conditioning-time that is optimum for all feeds; therefore, innovations will make conditioning time a controlled variable. This may be done by shaft speed and/or pick angle control. Time will be controlled for each feed type and desired pellet quality.
It has long been recognized that conditioning resident time has an influence on conditioning and pellet quality. There are two new innovations from European equipment suppliers that were introduced in a recent VICTAM show.
1. Conditioner angle - nearly every conditioner is installed in the horizontal plane. By adding a hinge at the back of the conditioner, a mechanism to raise the front of the conditioner and flexible feed and discharge spouting, it is possible to have nearly infinite control on resident time. Under normal operation, conditioning would begin with the conditioner in the horizontal plane. Once stable operations are obtained, the conditioner can be inclined to extend retention time to the desired level.
2. Pick (paddles) angle adjustment – a new device has been developed in which the conditioner pick angle can be changed during operations. In this case, the conditioner shaft is hollow and contains the mechanism to rotate pick angle at any time.
Again, pelleting is initiated with a “standard” conditioner paddle angle. Once stable operations are obtained, the angle can be adjusted to increase or decrease retention time.
3. Steam or mash wiers (dams) - a relatively simple but effective modification to the conditioner is to install "wiers" or plates to block the exit of either steam (covering the top two-thirds of the conditioner) or mash (covering the bottom two-thirds of the conditioner). The top plate prevents the steam from traveling the length of the conditioner and exiting without being in contact with the mash. The bottom plate acts as a dam forcing the picks to elevate the conditioned mash over the plate opening. In this case, drug residue is a serious concern because between 50 and 200 pounds of feed will be left in the conditioner at the end of a run; however, both technologies offer a partial solution to conditioning problems.
4. Multi-pass conditioners- Many contemporary pellet mill installations are equipped with double or, in some cases, triple-pass conditioners. In most instances, this is not done to gain extremely long (>45 sec) retentions time, but to be able to hold a minimum retention time of 12-15 seconds. Many of these mills are capable of 40-50 t/hr and it simply takes two or three of the largest conditioners available to maintain even a minimum reasonable conditioning time.
Moisture Control
It is well known that pellet quality and production rate depend upon an acceptable level of moisture in the mash as well as temperature. There are moisture monitoring and control systems available today; however, improvements are needed in accuracy and reliability. We will be able to “dial in” a desired mash moisture just like weight controllers handle mash temperature today.
Formulating for Pellet Quality
The industry is getting close to having the ability to formulate for pellet quality just as we formulate for amino acids, minerals, energy, and so on. This is a more difficult challenge because pellet quality does not respond in a linear manner to increases or decreases in specific ingredients. With enough data, pellet quality should be predictable.
Pressure Pelleting
A new pellet mill design has been developed by PCI Inc. of Wichita, Kansas. Mash is conditioned under slightly elevated steam pressure to reach a temperature above 212 F. Early results for pellet quality and broiler performance are encouraging. At present, a concept machine is in operation at a broiler feed mill and at least two full-sized production mills have been installed in large feed mills.
Universal Pellet Cooker (UPC)
The UPC concept has been developed by Wenger Manufacturing, Sabetha, Kansas. This machine is actually closer to an extruder than a pellet mill, but the product is essentially identical to a pellet in appearance. Extremely high pellet quality is attainable with an UPC and it will find its way into many specialty applications like aquafeeds, starter diets, and high margin items such as petfoods.
Expanders
This concept of using high temperature-short time conditioners has found varied acceptance in the U.S. While improved pellet quality is nearly always obtained, projected improvements in animal performance have not always occurred. Maintenance and operating costs have been a shock to some who have installed an expander. Others have experienced health problems in pigs fed expanded feeds (ulcers). Some companies are exploring the possibility of expanding only (not pelleting). Density and flow problems have been observed but performance seems to be equal to pelleted feeds.
Coolers
Counterflow coolers have essentially dominated nearly all recent new construction. However, finished product moisture control has not been solved by any current cooler design.
I feel that coolers of the future will be equipped with moisture sensing and control and will be able to dry as well as cool products to a safe level. This will require both heating and cooling zones, air flow control, and sophisticated control schemes from vendors.
Post Pellet Additive Application
This area is presenting the industry with an immediate challenge with the introduction of such things as phytase enzymes and other heat sensitive additives. There is a real challenge in being able to apply 50 or even 25 gms of active material uniformly on a ton of feed. We simply cannot do this like we currently apply fats and oils at 20 to 80 lbs per ton.
Again, a lot of technology exists but is often judged to be too expensive to retrofit into an existing facility. This concept, however, should be incorporated in all new designs and construction. Loss-in-weight systems, or weigh belt or weigh screw feeders, have the ability to control pellet flow and signal a controller so that the correct amount of additive can be applied.
I feel that phytase is just the beginning of the low-inclusion, heat sensitive additives of the future. Other enzymes, drugs, vitamins, and biologicals may require the same or even higher levels of accuracy. My advice is to prepare now.
Blending
We have a bit of a conflict between feed mill managers and nutritionists. Nutritionists would like to have twelve to twenty different feeds for the life cycle of a pig or turkey and eight to twelve for a broiler. Most feed mill managers would like to have one feed per animal species. Therein lies the dilemma. The more formulas produced, the less efficient the feed mill in terms of production and loadout.
A few companies are experimenting with the concept of producing two or three basic formulas and then blending at loadout to create the correct feed for each stage of growth. It is theoretically possible to produce three feeds and create an infinite number of feeds to match the nutrient requirements of the target animal precisely at any stage of life.
There are practical problems that must be addressed. Blending requires additional weighment or proportioning devices of some type. Accuracy is an issue. Degradation of pellet quality needs to be addressed. Uniformity of the finished blend has to be at least as good as the original feeds. This is, however, a solution that will result in optimized feed mill performance and feeds that closely match the requirements of the target animal.
Summary
The most dramatic changes in automation technology feed processing are related to our ability to use and collect information to improve efficiency of both labor and machines. The evolution of new machines and processes is much slower, and, given the economic stagnation in animal agriculture, capital investment in new mills and hardware is proceeding but at a slow pace. Feeding practices, such as post-pellet application of microadditives and the inclusion of whole, unprocessed grain in diets, will be a significant challenge for existing feed mills.
