# Penn State Particle Separator

In this video Dr. Jud Heinrichs demonstrates the Penn State Particle Separator, a popular method for on-farm particle size determination.

### Instructors

Heifer nutrition and management Effective fiber for dairy cows

### View Transcript

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- [Voiceover] The Penn State Particle Separator is used by dairy farmers and nutritionists around the world to determine the particle size of forages and TMRs.

It's a popular tool because it's easy to use in the field or at the feed bunk.

And it produces repeatable results from as-fed samples in just a few minutes.

Dr. Jud Heinrichs and his graduate students developed this tool and have continued to improve it, as our understanding of how particle size influences the health and production of dairy cows has changed.

In this video, Dr. Heinrichs will tell you more about the Penn State Particle Separator and how to use it.

- This is the Penn State Forage Particle Separator.

It's designed very much similar to the ASABE separator, where we can actually calculate the mean particle size, and the mathematics has been worked out very well for us to look at average particle size of a feed.

It has screens that are 19 millimeters.

Seven millimeters.

Four millimeters, to give us effective fiber.

And a bottom pan.

Now one of the unique features about this is that the thickness of the screens are proportional to the diameter of the holes.

And that's one of the things that makes it work.

There's also available a screen which is one point one eight millimeters.

That's actually been determined to be the average size of a piece of feed leaving the rumen of a cow.

Some people may wanna use that, it gives us very fine particles, and tells us the amount of those fine particles of feed or TMR.

But a lot of people are more concerned about looking at physical effective fiber and that's where the four-millimeter screen comes in.

Everything above that is considered physical effective fiber.

Everything below that is considered something that's very small, even though its average particle size is greater than one point one eight millimeters.

Okay, so, what we do with this is, it's calibrated with three dry pints of material.

We put that silage on here, or in here, meant for a wet feed.

And then what we're gonna do is that we shake it 40 times.

So we take five shakes, turn it.

We do that eight times.

The idea is you're trying to get all the feed to go back and forth on these screens, allowing anything that's small enough to pass down through.

And the key thing in terms of shaking it, is to give it enough force so that your feed or TMR is able to pass back and forth over those holes, allowing it to pass down and through, realizing that you've got feed that is trying to pass all the way down into the bottom.

(separator grates loudly)

Okay, the only small thing that you have to keep in mind if you happen to have silage that has a lot of clumps in it, when you're about halfway through, you need to make sure that they would be all on the top, and you need to break those up.

In this case I didn't have any.

Well, you do this, from here on in, we take what's remaining on each of these screens, weigh it, record the weight, and then on our website, you will find a spreadsheet that you download and you can put the numbers in there, and it will plot mean particle size for you, and give you a distribution.

Or you can simply add up each of the amounts in the tray, and then look at the fraction, the proportion that's on the top, second tray, third tray and bottom tray.

And go back to your table and calculate based on what type of a ration this is.

This is a percent that it should be in that, in your feedstuff, in the range that it should be.