Why feed silos run empty and how to see it coming
Why silos run out even on well-run farms, why bridging makes the level hard to judge, and how a radar sensor on the silo roof shows what is left.
Water and feed 5 min read
The feeder lines go quiet on a Sunday afternoon. Someone checks the motor, then the auger, and finally climbs the silo to find what the lines have been saying: it is empty. The feed truck is not coming until Monday.
Every poultry manager has a version of this story. It rarely happens because nobody cared. It happens because the level in a silo is genuinely hard to judge from the ground, and the moment it matters most is usually the moment nobody is looking.
What running out costs
When feed stops reaching the pans, birds that were eating steadily start competing at empty pans. When it comes back, they rush it. The disruption shows up in uneven intake across the flock, stress in the house, and a day of growth that the flock does not get back. For layers, an interruption can show up in production. Your nutritionist or veterinarian can tell you what it means for your birds; the practical point is that it is entirely avoidable.
There is also the cost on the other side. Ordering early “just in case” means paying for rushed deliveries, keeping more feed standing than you need, and sometimes running out of silo space when the truck arrives.
Why the level is hard to judge
A silo is a tall, closed, dusty cylinder. The usual ways of checking it all have limits:
- Climbing and looking is accurate if someone does it, and it is a safety risk and a chore, which is why it gets skipped.
- Tapping the wall gives a rough idea from the sound, and depends on who is tapping.
- Sight glasses and windows show the level at one point, which may not be where the feed surface is.
The feed itself makes it harder. Feed rarely sits flat. It forms a cone when it is filled and a crater as it is drawn from the bottom. Worse, it can bridge: feed arches over the outlet and stops flowing while there is still feed above. Or it can rat-hole, flowing down a narrow channel in the middle while the rest stays stuck to the walls. From outside, a bridged silo can look like it has plenty left while the lines are starving, and a rat-holed one can look nearly empty when it is not.
Measuring from the roof
A level sensor mounted on the silo roof, pointing down, measures the distance to the feed surface. Knowing the silo’s dimensions, that distance becomes a level, and the level can be read on a phone without anyone climbing anything.
Radar is well suited to the job. It measures without touching the feed, so there is nothing to wear or clog, and it is not thrown off by the cloud of dust inside a silo during filling. A high-frequency radar has a narrow beam, which helps it see the feed surface rather than the walls and ladders inside.
A continuous reading also shows things a single look cannot:
- The rate of use. Level over time shows how fast the flock is eating through the silo, which is what you need to plan the next order.
- Filling. A jump in level confirms a delivery arrived, and roughly how much went in.
- Stopped flow. If the lines are running but the level is not moving, feed is not leaving the silo. That is the signature of a bridge, and it is worth checking the same day.
Turning level into days of feed
A level on its own is not the number you plan with. What you want to know is how many days of feed are left, which depends on how much the flock is eating, and that changes every day as the birds grow.
The feed silo calculator does that arithmetic: silo contents in, daily consumption in, days left out. Use your own consumption figures from your feed records or your breed management guide; they will be closer to your house than any general number.
With a continuous level, the same calculation can run every day. An alert set at the level that covers your supplier’s delivery time, plus a margin for weekends and holidays, gives you a reminder while there is still time to order at normal prices.
Where to mount the sensor
A few practical points from installation:
- Mount it on the roof, away from the fill inlet, so the falling feed during filling does not hit the beam directly.
- Aim at the part of the silo that empties, usually toward the centre above the outlet.
- Keep it clear of internal ladders and bracing that could return an echo.
The installer sets this up once. After that, nobody needs to climb for a reading.
The same house problem often starts at the other end of the line: for water, see a drop in water intake as an early warning sign.
How Henlytics does it
Henlytics mounts an RLM-120 radar level sensor on the roof of each silo. It operates at 76 to 81 GHz and reports over RS485 Modbus to the Genesis controller on the house, which sends the readings by cellular to the same dashboard as the rest of the farm. You set the low-level alert, and the whole team gets it on their phones.
See feed silo monitoring for the sensor and how it is installed.