Our pulsators are something we rely on every day, twice a day, like so many things at the dairy. When everything’s working correctly we can forget how vital things like this are to our operation. Two weeks ago half of our pulsators quit working, and we got a brutal reminder of just how important they are.

What is a pulsator?

The pulsators are really what makes the milking units work. You can have all the suction in the world, but without a pulsator, you don’t get milk. The vacuum pump provides the suction to the milking units while the pulsators cause the shell liners to move in and out, basically squeezing then releasing on the cow’s teats.

If you’ve seen someone milk by hand you know they don’t just pull and hold, you have to pull and squeeze and release and pull and squeeze again. That’s what the pulsators do using differential pressures on the inside and outside of the liners. They also alternate so that two teats are squeezed and two are released at all times. Our pulsators are fairly loud, so you can clearly hear them switching back and forth. I guess they provide the rhythm for milking.

Here’s a short video with clips of a couple of cows milking. With our (new) clear shells, you can actually see the black liner squeeze and release. You can also hear the rhythm of pulsators and see the milk flow alternate between teats.

When the electrical box for the pulsators on one side of the barn quit, we were able to get both sides wired through one box so we could get by. They didn’t have quite enough juice, though, so a few units wouldn’t work correctly, and it really slowed things down. We milked with disabled pulsators for three days before we were able to get them fixed (it was a weekend, of course). After that experience, we’re a little more grateful for things like our pulsators and vacuum pump that really make our lives easier when they work twice a day every day.

Related articles

• Can herd somatic cell count be too low?
• Dumping Milk.
• Dairy farmers say daylight saving throws cows for a loop, too