Pet food changeovers are becoming more frequent as manufacturers introduce single-protein and prescription recipes onto process lines originally built for long kibble runs. Each changeover increases total turnaround time and risks transferring protein from one recipe to the next. As consumer demand for quality pet food increases and contamination issues persist, this post is designed to answer questions arising in powder handling applications for pet food manufacturing.
How do you reduce changeover time and allergen carryover in pet food production?
Use enclosed conveyors for total batch transfers, make chemische Reinigung the default method, provide machinery with tool-free access for maintenance, and reduce transfer points. These changes address five common risks in dry ingredient bulk material handling: conveyors retaining residue between recipes, hard-to-reach dead spots in conveyors, open bag tipping, shared batching hoppers, and equipment requiring tools for maintenance access.
Why are pet food plants changing over more often?
Traditional kibble lines were built for large pet food manufacturing equipment and high volumes. The market wants those same lines to make more products in smaller batches. According to the American Pet Products Association (APPA) 2026 U.S. Pet Industry Trends & Forecast, while demand is growing, price sensitivity is rising as well, requiring lines that are more flexible.
Specialised diets add to that variety. Single-protein, limited-ingredient, and prescription recipes each need their own formulation. They often share pet food processing equipment with standard recipes, creating new opportunities for cross-batch contamination. For example, Hill’s Pet Nutrition launched single-protein Science Diet dog food rolls in June 2026 and expanded its kidney-focused prescription diets for cats and dogs.
Co-manufacturers see the effect most. One plant may run recipes for several brands through the same intake, conveying, and batching equipment, each with its own protein sources and label claims. Smaller batches add to the problem, because each changeover takes a bigger share of a shorter run.
This article deals primarily with dry ingredients used in powder handling, where Förderung von Tierfutter and batching equipment handle meals, grains, premixes, and coating powders. It’s worth noting, however, that fresh and raw protein ingredients are also growing, bringing their own separation and sanitation demands with them.
Every changeover costs time and risks carryover
What counts as a changeover?
A changeover runs from the last good output of one recipe to the first good output of the next at full rate. It includes clean-out, inspection, any required testing, and the ramp-up to regular processing speed.
Extra time used in changeover shows on the production schedule. A line running multiple recipes is more costly than one running a single variety of kibble. Every clean-out, swab, and restart of a pet food conveyor takes time from production and increases costs.
When residue from one recipe reaches another, the second product can contain protein not declared on its ingredient label. Vets use single-protein and hydrolysed diets in elimination trials to diagnose adverse food reactions. An undeclared protein is one reason why a trial fails.
Studies of limited-ingredient / single protein diets show the problem is pervasive, especially in dry pet food processing. Fossati et al. (2019) tested 21 over-the-counter canine dry diets sold as limited ingredient / single protein. They found DNA from undeclared species in every one of them. By contrast, undeclared animal DNA was found in more than half (six of 11) of the limited-antigen wet diets tested in the Ricci study.
Both studies used PCR (polymerase chain reaction), which picks up very small traces of DNA. Neither could tell process carryover from deliberate substitution, or pinpoint where the protein entered.
Where residue hides in the dry ingredient path
The hammer mill, mixer, and coating drum are the obvious clean-out jobs in a dry pet food plant, and each has its own procedure. The pet food manufacturing equipment that moves and batches dry ingredients between them is spread across the plant, but every recipe passes through it.
Intake: Manual bag tipping
Tipping bags into an open hopper releases dust, and some of it settles on nearby pet food processing equipment and the floor. Spills around the tip point widen the area that needs cleaning at every changeover.
If the next recipe excludes that ingredient, every surface the dust touches becomes part of the full clean. An enclosed bag dumping station connected to dust extraction reduces dust contamination by keeping the powder inside the system.
Conveying: Residue held inside conveyors
Every type of conveyor experiences material residue at the end of a run. Pneumatic lines can leave product in bends and in the filter receiver. Screw conveyors keep a layer in the clearance between flight and trough, and bucket elevators collect material in the boot.
Die EHEDG GL 22 hygienic design guideline for dry particulate materials names material left in equipment after shutdown as a design concern. Whatever stays behind must be removed during clean-out or it travels into the next recipe.
Dead spots and hard-to-reach surfaces
Brushes and vacuums have difficulty reaching places where powders get trapped, such as crevices, ledges, poorly fitted seals, and dead legs. EHEDG Doc 8 wants to see product-contact surfaces that are easy to reach for inspection and manual cleaning.
Fatty ingredients such as meat meals and palatant powders tend to smear and build up in these spots. Installation of equipment can add new dead spots to well-designed equipment through extra fittings or poorly supported bends.
Shared batching and weighing points
Majors, minors and micros powders often pass through the same hoppers and scales, so every recipe touches them. The minors matter most, because recipes differ for premixes and palatants.
Small amounts left on a scale or in a hopper can change what the next batch contains. Scoops and hand tools collect residue as well, unless each ingredient group has its own set of operator tools.
Poor access for cleaning and inspection
If a clean-out starts with spanners, it’s going to increase the time needed to turn around a batch. Bolted covers and guards needing a fitter to open them add time to every changeover.
Operators can’t confirm a surface is clean if they can’t see it, and time pressure or lack of training means these things can get missed. The gap tends to show up later as a failed swab or a positive first-off test.
Table A: Where changeover time and carryover build up
| Risk point | Adds clean-out time because… | Adds carryover risk because… | What to look for |
|---|---|---|---|
| Residue in conveyors | Retained material must be removed by hand or flushed | Retained material is released into the next recipe | Does the conveyor empty fully at end of run? |
| Dead spots/crevices | Hard to reach; needs disassembly | Residue survives cleaning unseen | Smooth contact surfaces; no ledges or dead legs |
| Manual bag tipping | Dust and spills spread the clean-up zone | Airborne powder settles on other equipment | Enclosed tip point with dust extraction |
| Shared batching points | Every recipe touches the same hopper or scale | Minors and majors share surfaces | Separate major/minor paths; cleanable hoppers |
| Poor access | Tools and bolted guards slow teardown | Operators can’t confirm what they can’t see | Tool-free access; quick-release connections |
Dry, wet, or CIP: which cleaning method suits a dry pet food line?
The cleaning method determines how long a changeover takes and how much residue is removed during cleaning. In a low-moisture plant, the main trade-off is water. The Codex code of hygienic practice for low-moisture foods calls limiting water one of the main ways to control pathogens. It suggests using equipment designed to clean with little or no water.
Flushing and sequencing
The lightest option avoids a full clean. Feed mills commonly run a flush batch of neutral material, such as rice, through the line. They also sequence recipes so each one tolerates traces of the last. US feed regulations accept this method to control drug carryover between batches in medicated feed.
Sequencing works well for changeovers using the same protein. A single-protein diet following a different protein, say a chicken batch following a beef batch, requires a full clean.
Chemische Reinigung
Dry cleaning removes residue with vacuums, brushes, scrapers, and product flushes. Without water, there’s no drying time. The line can restart as soon as it passes inspection.
Allergen specialists writing in Food Safety Magazine note that dry methods “can be more challenging” for removing allergen residue, so validate them against your hardest ingredients. Compressed air should be handled with care. Codex allows dried, filtered air in special cases, but blowing down a line can spread residue to nearby equipment and idle lines, making allergen cleaning validation difficult.
Controlled wet and wet cleaning
Controlled wet cleaning puts a small amount of water on specific parts, which are then dried completely before restart. Full wet cleaning removes protein more reliably, but it brings water into a dry plant.
Once residues get wet, Salmonella can multiply quickly and lead to pet food recalls. Residue that dries after a wet wash can cause its own problems. For example, residue may not be visible, and it can set into a hard film that’s tougher to clean the next time.
| Method | How it works | Changeover time driver | Protein residue removal | Moisture risk | Floveyor ranges listed |
|---|---|---|---|---|---|
| Flush or sequence | Neutral flush material, or a planned recipe order | Flush run time | Partial. Suits same-protein changeovers only | None | Not applicable |
| Dry | Vacuum, brush, scrape, purge; no water | Access and residue volume | Good if equipment empties fully; must be validated | None | All AMC ranges; TDC |
| Controlled wet | Limited water on specific parts, then dry | Drying before restart | Better on stubborn soils | Low, if dried | Elementa, Nutria, Pura |
| Wet/wash-down | Water and detergent, often with disassembly | Teardown + drying | Most reliable | Highest in a dry plant | Elementa, Nutria, Pura |
| Reinigen an Ort und Stelle (CIP) | Automated wet clean of enclosed equipment | Cycle + drying | Reliable, repeatable | Contained; still needs drying | Pura (CIP wet clean, steam sterilise) |
Validate once, verify every time
- Validation determines whether the procedure removes residue from your worst-case ingredients by using allergen-specific swabs and tests on the first product off the line.
- Verification confirms the operators followed the procedure at each changeover, often with adenosine triphosphate (ATP) or general protein swabs.
If you’re unsure whether your residue-prone ingredients will dry clean, send us samples and we’ll run them in our R&D centre.
How equipment design shortens changeovers
Most risk points are related to equipment design, so you can write them into a specification. When you compare conveyors and intake equipment for a multi-recipe line, here’s what to look for:
- A fully enclosed product path from inlet to discharge
- Complete emptying at the end of each run
- Smooth, crevice-free contact surfaces
- Access to contact parts without tools
- Sealed connections that come apart quickly for cleaning
- Materials suited to the cleaning method you’ve validated.
Next, ask the OEM to show how the equipment meets each one. If available, get the conveying equipment supplier to material test your most residue-prone ingredients through it before you buy.
Where Floveyor fits
Our flugmechanischer Förderer (AMC) range is built around several of these criteria. The product is fully enclosed, allowing the AMC to make total batch transfers, with negligible residue between batches. That’s the condition dry cleaning depends on.
At The Lupin Co, five Floveyor F3s move lupin seed, flake, and flour between processes. “When we finish a production run, in about 60 seconds we’ve got a totally whistle-clean system,” Managing Director David Fienberg said. The plant runs lupin products only and clears the conveyors with a sequence of air pulses, so the figure shows how quickly the line empties at the end of a run. A changeover between proteins would still need its own validated clean.
Für conveying pet food, Floveyor offers three AMC ranges, all certified to American FDA and EU EC regulations. They include:
- Die Elementa range is designed for low-risk dry foodstuffs and moves up to 54 tph (60 US tons/hr).
- Die Nutria range brings clean design to more demanding food processing, with capacity up to 30 tph (33 US tons/hr).
- Die Pura range adds CIP (clean in place) wet cleaning and steam sterilisation and meets EHEDG guidelines, making it Floveyor’s most sanitary conveyor. Like the Nutria range, the Pura range moves up to 30 tph (33 US tons/hr).
Where one conveyor needs to feed several points, a Rohrkratzerförderer (TDC) runs up to 75 m (246 ft) through a fully enclosed tube with multiple inlets and discharge points. It’s well suited for complex routes and conveying over multiple planes. Using one pet food conveyor in place of several means fewer transfer points to clean.
Bei einer recent installation for a national Australian foodservice distributor, an Elementa F4 handles quick changeovers on a packaging line between allergen and non-allergen products. Sealed flexible connections at each interface can be quickly removed for cleaning. Tool-free quick-release clips on the guards give operators fast access to keep production schedules on time.
Which line layout choices reduce allergen carryover?
Process line layout, along with scheduling, shortens changeovers and reduces the risk of allergen cross contact. Here are five ways to help lower the risk of contamination in lines running multiple recipes and products.
- Sequence recipes with a protein matrix. Map the proteins in each recipe and run recipes that share a protein back-to-back. The Allergen Bureau suggests using a cleaning matrix to map out how to group your batches. A changeover within the same protein group may then need only a flush, saving the full clean for when the protein changes.
- Dedicate equipment for the most restrictive diets. Hydrolysed and single-protein diets are at the most risk for allergen cross contact and have the least tolerance for carryover. Giving them their own intake and conveying equipment removes risk. CAPEX costs are higher, but it makes sense if those types of recipes are run frequently or your brand reputation is at risk if cross-contamination occurs.
- Reduce transfer points. Every surface between conveyors, hoppers, and bins has to be considered. EHEDG GL 36 Hygienic Engineering of Transfer Systems for Dry Particulate Materials links fewer product transfers to a more compact plant and reduced cleaning time. A Rohrkettenförderer-Verteilersystem has multiple discharge points in one conveyor.
- Enclose tipping. Our formulation systems support total batch transfers and combined discharge methods. Tip minor ingredients through a bag dump station with a dust hood connected to plant extraction. Batch majors from bulk bags through a bulk bag unloader on a separate path so the two streams share fewer surfaces.
- Give each allergen group its own cleaning tools. Colour-code brushes, scrapers, and vacuum attachments by allergen group. Clean up spills of allergenic material straightaway, before foot traffic and air movement spread them.
Floveyor bag dump station wtih dust hood for matching minors for formulations.
Proof in production: Advanced Pet Care
Advanced Pet Care of Australia (APC) makes its own brands of pet food and treats in Western Australia. It also manufactures pet food under contract for international and national companies. About 90% of its dry kibble is exported, mostly to Asia.
APC runs five Floveyor aero-mechanical conveyors and has been a customer since 2001. A Floveyor F4 moves powder mixes for dog food at about 4 tph (4.4 US tons/hr) across two shifts, for 16 hours a day.
Planned maintenance consists of a quarterly check of rope tension and general condition. Rope assemblies are replaced about every 12 months. “It’s a fast, low-maintenance conveyor,” Production Manager Ron Conway said, adding that “some ropes have gone for a lot longer than 12 months.”
Read the Advanced Pet Care case study.
Pet food changeover frequently asked questions
Everything from the last good output of one recipe to the first good output of the next at full rate. That includes clean-out, inspection, any testing, set-up and the ramp back up to speed.
Cross-contact is the unintended transfer of an ingredient or protein from one product into another. Cross-contamination usually refers to microorganisms. A changeover clean has to deal with both if you expect a sanitary conveyor for pet food processing.
It can be, if the equipment empties fully and the method is validated against your hardest ingredients. Wet cleaning removes protein more reliably, but it adds drying time and brings water into a dry plant.
When hygiene risk is high or changeovers are frequent enough to justify the capital cost and drying time. Lines that can validate dry cleaning for their ingredients may not need CIP (clean in place).
Use a protein matrix. Run recipes that share a protein back-to-back, flush between them where validated, and schedule the most restrictive diets after a full clean or on dedicated equipment.
A fully enclosed product path, complete emptying at the end of a run, crevice-free contact surfaces, tool-free access and sealed connections that come apart quickly for cleaning.
Test your recipes before you change the line
If your pet food line runs more recipes than it was built for, we can help you map out the most efficient way to manage the new demand. Send us samples and we’ll run them through an aero-mechanical conveyor in our R&D test facility, so you can see how cleanly the AMC empties.
You can talk to one of our powder handling specialists about the changeover points on your existing line. Tell us how many recipes you run and which ingredients cause the longest clean-outs, and we’ll come back with options.
To find out how a Floveyor aero-mechanical conveyor can prevent contamination in your pet food application, sich melden.
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