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Milking Procedure

The mammary gland is an excretory gland, meaning that it produces a fluid that is secreted to the outside of the body. These secretions leave the gland through a series of ducts that eventually open to the outside of the skin. The presence of these openings not only means that the mammary secretion can leave the gland, it also means that microorganisms can enter the gland. When that happens, the gland may become infected and present as a disease known as mastitis. Mastitis is an inflammation of the mammary gland, the inflammation most commonly being caused by an infection by a pathogen. Mastitis is the most costly disease in dairy cattle, but is also prevalent in other species, including our own. We will examine many of the aspects of how this disease is manifested using the dairy cow as our primary example in this module. We will examine mastitis at the level of an individual cow, as well as at the whole herd level. And then to fully integrate and apply the knowledge gained about this disease, we will examine several real-life cases of herd-level mastitis problems faced by dairy producers.

Lactation and especially milk, which is the product of that unique mammalian process, are routinely encountered within our daily lives. Nevertheless, they often are poorly understood by many, even including many who are engaged in the business of producing milk. The overall course goal is to introduce fundamental concepts that form the basis for understanding the biology of lactation, the biology of the mammary gland, and the products of that important physiological process. As a learner in this course, you will be provided with a series of easily understood presentations that collectively will help you build a foundation for greater understanding of lactation. You will be able to engage with other learners so that you can extend your learning beyond the video presentations. Ultimately, you will be able to construct your own mental model for understanding the wide range of topics that relate to the biology of lactation. Upon completion of the course, you will be prepared to expand your knowledge and understanding of lactation from other sources and experiences as you pursue your individual interests. Before you start the course, I suggest that you identify a question or several questions about lactation that you already have on your mind. This could be from your own experiences, something you read about or saw, or something you have wondered about. Write down your question(s) and use that to help you decide how to engage with the content of this course. You might engage with the modules in the order they are presented, or start with a module that is of particular interest to you, or pick and choose modules in any order. I encourage you to engage in all of the types of learning activities that this course has to offer, including but not limited to, the discussion forums, quizzes, peer-review assignments, and concept maps and other learning aids.

Impartido por:

Dr. Walter Hurley, PhD
Professor Emeritus

Transcripción

[SOUND]

So, in videos coming up, what we're going to do is, we're going to examine some real cases and real dairy herds,

and some mastitis cases in those herds.

For those who are not that familiar with cows, and

dairy farming, and all those kind of things.

This video is one that I think it'll be worth your while to spend

few minutes going through.

Because in this case, we're going to look at the milking process which the one we

use here at the University of Illinois Dairy Farm.

And then, I'm going to very briefly describe the milking machine.

But to do those things, we need to go out to the dairy farm.

So, that's what we're going to do now.

We'll see you out at the dairy farm.

So, we're back at the University of Illinois Dairy Research Center.

We're down in the parlor right now.

They're in the process of milking cows.

So, there will be some activity around us.

I want to demonstrate the normal milking procedure using this cow as an example.

When we are preparing the cow later,

we're actually working on two very critical things.

One is we're trying to get good milk injections.

In order for this machine to work effectively, give all the milk out.

We need to get out of here, we have to have good milk ejection.

So, a lot of what we're doing is stimulating milk ejection,

we've talked about that in other videos.

The other thing is, we're controlling for mastitis.

Again, we've had other videos relating to mastitis,

it's the major disease in dairy cattle.

It's an inflammation of the mammary gland, usually caused by bacterial infection.

So, it's really critical that you get these teats good and clean.

Good hygiene in the teats, so

that we minimize the chances of her getting mastitis.

So, first thing we're going to do is to take a dipper.

This is an iodine based teat dip.

It's called a pre-milking teat dip, and we're going to dip.

Make sure it's good and full there, we're going to dip each teat.

Get good coverage around the teat, so that germicide.

Let that work a little bit, but then strip out a few squirts of milk.

We have a black mat down here under her feet.

We're doing if she has mastitis, clinical mastitis,

she probably is going to have flakes or clots in the milk.

And we'll be able to see those flakes or clots as they hit the black mat.

So she's doing fine.

She's got no flakes or clots in them.

So, we dip them, we strip them, and we're going to dip them again.

She's already got milk ejection going on right there, put that back.

Now, we want to wait at least 30 seconds,

remember, milk ejection is not instantaneous.

It takes some time, so we just took a number of seconds there.

We want to mede at least probably have a minute or more, to get good milk ejection,

even though she's actually getting milk ejection already.

So, after about 30 seconds or so we're going to use a cloth towel.

These are clean, fresh out of the washing machine.

One towel per cow.

We don't want to then use this towel on this cow, and then go to another, and

then potentially contaminate that cow.

For waiting for this, again she's got good milk injection happening already probably

when she walked into the parlor.

But, we want to make sure that we also give time for the germicide to work,

while we're waiting for that I'm wearing plastic gloves.

And what we find is that bacteria are better at hanging or sticking to the skin,

so we can potentially contaminate one cow to the next one, when we use bare hands.

So, we use plastic gloves and we take this off periodically and put on fresh gloves.

So, again, so you get good milk ejection going on already.

And what we're going to do is put the machine on.

And I'll describe a little bit later, I'll describe how this machine works.

But right now, there's no vacuum in it, so we want to turn the vacuum on.

This has something called an automatic takeoff, and

we'll describe that a little bit more in a moment.

But that's what this chain is for.

So, we will put the machine on, but the machine will detect the milk flow,

when the milk flow rate drops to a certain point.

The machine detects that, the computer detects that.

Turns off the vacuum and this chain will retract and pull the machine off, so

we don't actually have to do that.

[NOISE] We'll adjust this so that the machine is hanging down pretty well

straight under the cow, the machines are on, you can see lots of milk coming out.

Again, she already kind of had milk ejection before I

even started preparing her udder.

The milk's coming out of each of the teat cups, these are called teat cups,

coming through the bowl, going down through this pipe to a machine down here,

which is essentially the milk meter.

This is what's actually determining how much milk she's giving.

Goes then out this line, it's called the lower pipe line.

It's a stainless steel pipeline.

That's what carries the milk over to the bulk tank.

This is the computer screen up here.

It's kind of hard to see with the lighting we have in here.

It gives her number, at the very top is her number, which is 8965.

Right under her chin she has a canvas strap on.

Right under that's a little green transponder.

It sends a signal when she walks in,

there's a green box right under her chin up there.

And that receives the signal.

So, as soon as she steps in here, automatically the system knows who she is.

It has all the information about that particular cow, that sends a signal over

to the computer room which then pops the information back up here.

The next number down is how much milk she's giving.

And then, we still record just in terms of pounds, right now it's 18 and

a half pounds that she's been giving already.

It will usually take five, six minutes for one of these cows to milk out,

at this farm we milk three times a day, so roughly every eight hours.

So now that we're done, she's done milking,

the automatic take all system took the machine off.

Again, what it did was detected the milk flow rate had dropped to a point,

where there wasn't that much milk coming out.

Turned the vacuum off, and then this chain retracts and pulls the machine off.

Now, what we're going to do is you're going to use another dipper.

Both of these dippers are iodine-based.

And we want to make sure we get it good and covered, so swish it around good.

And this one, we leave on there because the, especially after they're milked

with a machine, the teat canal, the opening in the base of the teat,

stays open for roughly an hour, or something like that.

And so, we want to make sure when she walks out of the parlor that she's got

that extra protection of the germicide on the end of her teet.

So, we don't wipe off that last, little bit.

So, that's how we milk a cow here.

What I want to do now,

is I want to explain a little bit how this machine works.

This is a little bit different machine, but

it essentially functions the same as the ones we were demonstrating on that cow.

What we have is called a teacup.

It's got a shell, this is a hard shell, was particular one is stainless steel.

The ones we were using were molded plastic.

It's got a liner, This is called the liner, and it's rubber, so

it's collapsible.

We'll come back to that in a moment.

This part up here is called a claw,

you can see because all these parts sticking out that's called the claw.

That's what this stick on to and then, under here is called the bowl.

And so, the milk collects milk in four teats, down in the bowl,

and then comes out to the milk flows going down to the pipeline.

What I want to do now is to talk for a moment about this one.

So, there's a constant vacuum being drawn on this.

Remember, the teat's in here, the teat is in here,

contents of the vacuum being drawn down here.

Now that's okay, it's pulling the milk out.

But, if you put your finger in your mouth, and

you suck on your finger, eventually you're drawing, or

you're preventing the blood in the limb from going back up the teat.

Eventually, what that's going to do is cause a lot of congestion

in the base of the teat.

Potentially increase the instance of mastitis and those kinds of issues.

So, you really don't want a constant vacuum, here.

So, what we have is, if you recall,

we have a collapsible liner, we have a hard shell.

This other tube is also connected to a vacuum.

But, it's alternately pulling out vacuum,

pulling the air out, putting in atmospheric pressure.

It's going back and forward like that.

So, what happens is then, when it draws the vacuum here,

this opens up, milk is going to then flow out, because again,

remember, there's constant vacuum here.

When it lets atmospheric pressure in, it closes down around the teat.

So, it's essentially doing this the whole time, just like that.

Very similar to a calf's tongue suckling on the cow.

So, it's pulling milk out, massaging the teat.

So, it has a milk phase, that's when milk is flowing.

And the rest phase is when atmospheric pressure comes in this inner chamber, and

collapses around the teat, and again, you're massaging the end of the teat.

So, essentially the whole time the cow's being milked it's going like this.

What regulates that is something called a pulsator.

Once a second it's going [SOUND] back and forth, back and forth, and so

that's how fast it's milking.

So, that's essentially in a nutshell, how this thing works.

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