The mix comes out of the vertical mixer looking exactly right. Penn-state shaker box numbers are on target, liquids are distributed, fibre length is where the nutritionist wants it. Then the delivery wagon runs 800 metres (half a mile) to the far pen, hits a gravel crown at the yard gate, and by the time the gate swings open the ration has already started to fractionate. Fine particles settle. Long stems work their way to the surface. The operator discharges into the bunk and moves on, and nobody sees the problem until feed sorting picks up or the nutritionist pulls particle analysis and starts asking questions.
This is a well-understood failure mode in large beef and dairy yards, and it happens most often not because the mixer was wrong but because the delivery wagon was never treated as part of the ration system. It was treated as a box.
What Happens to TMR in Transit
Vibration is the main enemy. On a smooth floor it is manageable. On the gravel and packed-clay surfaces common to Alberta feedlots, a loaded wagon bouncing at road speed generates enough vertical acceleration to stratify a freshly mixed load within a few minutes. Long-stem hay and straw migrate upward. Wet silage particles and liquid supplements sink. By the time the wagon reaches a distant bunk, what discharges first bears little resemblance to the batch average.
The physics are straightforward: denser, wetter material settles under vibration while lighter material floats. A ration with adequate effective fibre has enough structural integrity to resist some of this, but the resistance drops fast as fibre length shortens or as the load shifts during a partial discharge. The dynamics of TMR segregation during delivery are worth understanding in detail if your operation is seeing inconsistent bunk presentation across pens.
Speed matters too. A wagon driven at 20 km/h (12 mph) over rough ground moves differently than the same wagon driven at 10 km/h (6 mph). Most yards have no formal rule on this, and operators under time pressure default to fast. A route map that identifies rough sections and sets a realistic speed limit costs nothing and prevents more sorting than any equipment upgrade.
Matching Wagon Volume to Batch Size
Partial loads are a bigger problem than most managers realise. When a mixer produces a 12-cubic-metre batch and the delivery wagon holds 20 cubic metres, somebody has to decide what to do with the empty space. In practice, operators top up by eye: a few more forkfuls of silage, some loose hay, whatever is close. The result is a ration that was never actually mixed, delivered to a pen alongside one that was.
The fix is straightforward in principle. Match the wagon volume to the mixer batch size so that a full mix fills the wagon without excess. If your mixer produces two sizes of batch, run two wagon configurations or accept that the smaller batch goes to the closest pen at reduced risk. The temptation to improvise disappears when there is no space left to fill.
Getting mixer sizing right in the first place is what makes this possible. An operation running the wrong mixer size produces awkward partial batches by default, and no delivery protocol fixes that upstream problem. Mixer sizing and the daily cost of getting it wrong is worth reviewing before you blame the delivery wagon for inconsistency that actually starts at the mix.
LEO Agriculture’s 25 Series feed delivery wagons run from 28 m³ to 40 m³ (1,000 ft³ to 1,400 ft³), with larger custom boxes available on request for truck-mounted or trailer configurations. That range suits operations where the mixer is a central stationary unit and the wagon is doing genuine distance work across a large yard.
Route Order in Summer Heat
In July and August across central Alberta, ambient temperatures at midday routinely sit above 28°C (82°F). At those temperatures, the safe window between mix completion and last bunk delivery shortens considerably. Feed temperature rises in the wagon, aerobic activity accelerates if the load sits still, and palatability starts to drop before the far pens are fed.
This is not a theoretical concern. Any operation running corn silage with a high moisture content knows that summer TMR goes off faster than winter TMR. The delivery route is the only variable the operator controls once the batch leaves the mixer.
Route order should be planned so that the pens with the highest-value animals, or the groups most sensitive to ration variation, receive feed first. Hospital pens and fresh cows cannot afford sorted, warming feed. Backgrounder pens further from the mixer can tolerate a slightly longer transit without the same consequence. Plan the route around animal priority, not around what is most convenient for the tractor path.
A few practical points on summer delivery management:
- Mix and deliver in the coolest part of the day where scheduling allows. Morning delivery before 9:00 AM buys meaningful time before ambient heat peaks.
- Avoid stopping the loaded wagon in direct sun. A black steel box sitting in full sun on a 30°C (86°F) day gains heat faster than most operators account for.
- Keep discharge time short at each bunk. The longer the wagon door is open and the load is exposed, the faster surface temperature rises.
- Where multiple trips are necessary, mix for the far pens last and deliver directly rather than holding a mixed load while near pens are fed first.
Loading Practice at the Mixer
How the wagon is loaded affects transit performance as much as the route does. A wagon loaded in a single concentrated dump from the mixer discharges differently than one loaded progressively during a mix cycle. If your operation uses a stationary mixer that discharges into the wagon, check that the discharge point distributes load across the wagon floor rather than piling it at one end. An off-centre load shifts under cornering and increases the risk of tipping on sloped yard surfaces.
On operations where the mixer wagon drives alongside the bunk and the delivery wagon is a separate carry unit, the transfer point is worth watching. Operators sometimes allow the transfer to happen at speed to save time. A slow, controlled transfer keeps the mixed structure intact. A fast one starts the separation process before the delivery wagon has moved a metre.
The Wagon as Part of the System
Large yards in Alberta and Ontario that run a central vertical mixer often invest heavily in the mixer and treat the delivery wagon as a commodity purchase. The thinking is that a wagon has no moving parts in the mix, so quality does not matter. What actually matters is floor geometry, discharge speed, load distribution, and structural rigidity under vibration. A wagon that flexes at the frame on rough ground creates internal movement that promotes separation regardless of how well the mix was made.
The delivery wagon is the last piece of equipment the ration passes through before the animal eats it. Treating it as a controlled carry, matched in volume to the mixer batch, driven on a planned route in the right order, loaded correctly and driven at a speed the ground conditions actually allow, is not extra work. It is what protects the work already done at the mixer.
Third cut is coming off right now across much of Ontario, and corn silage prep is underway across the Prairies. Ration composition is changing, which means transit behaviour changes too. Wetter, denser silage-heavy rations separate faster under vibration than drier hay-based ones. If your delivery protocol was built around last winter’s ration, it is worth revisiting before the silage season rations go into the mixer.
