The Pulse of Milking

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.

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What’s For Dinner?

Timer on the right now controls the feeders.

A lot goes into what a cow eats. Nutrition is incredibly important to many aspects of the operation. Not only does it affect their overall health, it affects their milk production, the fat and protein (components) content of their milk, and even reproduction and behavior.

We feed our cows a TMR (total mixed ration) twice each and every day after milking. It includes alfalfa hay, corn, corn silage, and a commodity blend.  The blend includes distiller’s grain, soybean meal, minerals and many other ingredients determined by our nutritionist and feed man at Wildcat Feeds.

We also feed our cows grain in the barn while they milk. This actually isn’t an ideal practice, but some time ago they stopped feeding in the barn and had a lot of trouble getting the cows to come in to be milked, so we started again and will likely continue until we build a new milk barn without feeders.

We recently had noticed reduced milk production along with some cows reluctant to come in or move up in the barn, so David looked at the ration to see if that might be the issue. We had been running our feeders manually with switches, which led to varying amounts of grain going to each string (group) of cows depending on when someone remembered to turn the feeders on and off. The first step to correcting the ration was to install timers so each cow would hopefully receive the same amount of grain while in the barn.

After the timers were installed, Dave tested the output of the feeders and found that there were significant differences in output between different feeders. He adjusted the outputs and tweaked the time so that each cow would get the same (appropriate) amount of feed every milking, no matter the order they come into the barn.  Previously, the grain fed in the barn had been only ground corn.  Cows prefer a consistent feed, so he also started mixing it with some of the commodity blend.

The results have been exactly what we hoped for.  We’ve seen a jump in milk production, and the cows are eager to come in the barn. Many of them are actually coming to the gate to be milked at or before milking time.  We just completed these changes last week, and there is usually some adjustment period, so we are hoping production keeps improving over the next week or two.