viernes, 29 de agosto de 2014

How to milk a cow

This National Geographic video explains the process of milking a cow in this day and age.

Self-study activity:
Watch the five-minute video and answer the questions below.

The activity is suitable for intermediate 2 students.



1 What substance makes finish off the cow's digestion in the fourth stomach?
2 What does '18' refer to?
3 How safe is it to drink milk straight from the cow?
4 How much time does an Automated Milk Harvester operate during the week?
5 How are the cows identify once they walk into the box of the Automated Milk Harvester?
6 Will the machine milk a cow that has 8 litres of milk?
7 What does '10,000 pounds' refer to?
8 How beneficial is for the cow's health this milking system?
9 What three elements are necessary for Neil Rowe to fix whatever problem in the Milk Harvester from anywhere in the world?

You can check the answers by reading the transcript.

This time, we're looking at something which has been consumed by mankind for thousands of years. We're talking about milk.
But first, how is milk created?  Well, in fact a cow has four stomachs.  The first stomach begins to break down the grass before it passes through the second and third stomachs where nutrient absorption begins.  Eventually, in stomach number four, gastric juices (1) finish off the digestion process and nutrients extracted from the food are absorbed into the blood stream.  In the udder, the blood passes through very small blood vessels, surrounding groups of secreting cells called Alveoli.  It's these that actually produce the milk using the nutrients carried in the bloodstream.  Aside from the food they eat, cows must also drink plenty of water. 18 litres of it produce just 4.5 litres of milk (2).
And the traditional way of milking a cow was of course by hand using a stool and a bucket, and I'm gonna give it a go.
Farmers going back to the Iron Age milked cows in this way.
Jonny is that the first time you've done that?
Yeah.  She's obviously very full because that's coming out without much encouragement, but, it's not as easy as it might seem.
There you go, girls.
The average cow produces about 27 liters of milk a day, but it has been known for cows to produce more than a 100 liters in a day.  And you can drink the milk straight from the udder (3), as I am about to demonstrate.  There we go whisky. There we go. That is absolutely delicious.
Technology has entered the world of the Moo Cow.  Richard and Jonny have come to one of the most modern dairy farms in Britain where a laser-guided robot milks the cows.  It's called an Automated Milk Harvester and it operates 24/7 (4), allowing the cows to enter of their own free will.
So talk us through the process, how does it work?
Okay, the cows walk on from this side.  Come into the box and stand there.  They're identified by a microchip (5), which they have in a collar on their necks.  The computer will then decide whether it wants to milk this cow or whether to let this one go and take the next one.  So it's trying to be as efficient as it can.  It's always looking to harvest the maximum amount of milk every 24 hours.
Why would it let a cow go then, why would it not milk one?
If she doesn't have enough milk in her udder, it won't invest six and a half minutes of its time for a small amount of milk, it's looking for a cow with about 10 litres of milk (6).
And sorry, just explain Neil, how does it know whether it's worth milking her?
It keeps a running total on every cow in the herd.  It can then calculate to within half a liter how much milk is in the cow before it starts to milk her.
And how many cows a day is it milking?
It'll milk 70 cows, 3 times a day.  It can do about 200 milkings over the 24 hour period.
And what's the most say, a cow can yield?
We've had cows on here that have given 100 liters in a 24 hour period.
Goodness me.
Which is extraordinary isn't it.
That's massive.
Once the robot has committed to milking a cow, a brush system first cleans and sterilizes the teats with hydrogen peroxide to prevent any infection being passed on.  The orange brush then massages the cow's udder to encourage the production of the hormone oxitocin, which is needed to stimulate the milk flow.
The milk comes down through these tubes, goes through this electronic box and there's 10,000 pounds worth of sensors in there which monitor the quality of the milk (7).  It can see watery substances, cow muck, dirt, blood.  Anything which isn't normal in the milk, it will see it, and then it separates that milk out into these buckets and then when the process is finished, it takes about uh, 4 seconds to chill the milk down from 37 degrees down to 2 degrees.
Goodness me.
And it's not just the milk that's chilled.  This system can prove much less stressful for the cows.  In fact on this farm they're actually living an average of 30% longer than those on farms where they use more traditional milking methods (8).  But what happens if something goes wrong with milking when the farmer is not around?  Well, this technology is so advanced the robot just contacts him over the phone (9)!
The system actually automatically contacts you if there's a problem?
It does, yeah.  It will ring me immediately, within seconds of identifying a problem.  There are about 100 sensors on here that can all detect whether it's working correctly or not.  Any one of those finds a problem, rings me straightaway, gives me a message to tell me what the problem is.  I can then text back codes to try and fix the problem from where I am, or even if I've got my laptop (9) and a wireless broadband connection (9), I can connect on anywhere in the world, using the cameras I can see what's going on and I can use my keyboard to sort the problems out.
Wow!