Background: why 15 inches vacuum in dairy systems

[Dale Mahalko]

(Just some background info on why all the old dairy equipment, that people are recycling for maple systems, normally runs at 15 inches of vacuum.)

Trees can handle much higher apparently..

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http://www.farmers.coop/fileadmin/fa...ions-Notes.doc

ORGANIC VALLEY / CROPP COOPERATIVE
“Ask the Experts” Proper Milking Systems Operations Conference Call with CROPP’s Quality Department: Steve Kretchmer, James Miller, Kevin Jahnke and CROPP Producer Clair Shirk
Dec. 1, 2011

3) Steve: Maybe you'd comment a little bit on the impact the vacuum has on mastitis and injury to the udder and how important that is.

Kevin: The vacuum is really important to the efficiency of the milker unit. Now on all the milker claws they have what's called a bleed hole and that's going to be a little pin hole in the claw to admit air to help push the milk away.

So if your vacuum is too high or too low, you're going to see uneven vacuum levels in that claw and when you get uneven vacuum levels it's called 'reverse jetting' where it shoots milk back up into the teat. So if you've got a cow with one quarter that has contagious mastitis in it and you're milking her with some faulty milking equipment you know there's a high probability that milk is going to get jetted up into other quarters and spread mastitis through her whole udder.

So the vacuum is critical to that. It's important that the pulsation is working right because that can contribute to that. If the vacuum is too high and/or the milker's left on the cow too long, it's what they refer to as overmilking, which basically means that instead of exposing that teat end to 11.5 to 12 inches of vacuum, which is ideal, the longer the milking unit hangs on the cow with no milk flowing out of it, the higher that vacuum gets until the claw vacuum matches the system vacuum which in most highline barns is 15.

When a cow's teat end is exposed to 15 inches of vacuum what it does is basically start to pull that teat inside out. Right on the very end of the teat, on the inner canal there's some tissue called keratin and that's protection against outside environmental conditions, protecting from things getting inside the teat and you'll start to pull that outside and when you look at the teat ends they'll have little rings around them or they'll actually look like a little funnel where they're starting to suck the teat end out.

That's not good for a lot of reasons but the biggest reason is that inhibits the cow's own natural defenses against bacteria when she's out and about, outside in the pastures or in the barnyard or whatever. So the vacuum and the maintenance of the system are really important to teat end health.

[maplwrks]

Trees can handle the high vac. Cows can't. Stick your teat over a pipe with 20" on it. You'll see why!!!

[DrTimPerkins]

Trees can handle much higher apparently..

Yes they can. This is because plant cells (most of them anyway) have rigid cell walls, which contain the cell contents to a given space. Animal cells don't have analogous structures, so they can be pulled apart by high vacuum.

"Reverse jetting" in milking cows is analogous to the problem of sap backflow in maple tubing systems, which is what the CV spout adapter is designed to prevent/limit. In either case, you forcibly spread the microbes back into the system where you DON'T want them.

[justin]

will 15 inches of vacuum work on small tubing system

[500592]

Ya any vac is better than none but dairy equipment will handle a little more about 18-20 hg is a good number

[Dale Mahalko]

Running the vacuum higher than 15" on a dairy pump will work the equipment harder than it was designed for, so it'll run hotter.

More cooling would be a good idea, like an extra fan blowing across the pump and motor. Though since you are only sapping in the winter, if you have the pump cooled with outside air, it will probably run fine.

Also most small dairy farms only ran the vacuum pump a few hours a day, while you may want to run it basically continuously for weeks.

More frequent oil changes, motor lubrications, belt replacements, etc may be a good idea to prolong its life. If you figure a farm only ran the vacuum pump about 3-4 hours a day, while you are running it continuously for weeks, you are running the pump 6-8 times harder than it was designed for. So if the manual says change the vacuum pump oil every year, you should do it after about two months.

[farmall h]

I grew up on a dairy farm and as a young ladd you tend to want to put the milking machine on others things than the cows teats....'nough said?

[500592]

Haha funny

[farmall h]

500592 you will only be running your vacuum pump when the lines are not frozen...not 24-7. You could run up 'till 11pm or until ice comes down.

[500592]

Farmall I think that was for Dale?