Thursday, 25 June 2015

How to milk a cow.

Several years ago, just before the Celtic Tiger rolled over and died, we had a Polak to stay for six weeks in the middle of Winter.  He came from the far North East up near the Lithuanian border. Tadek was even older than me and his farmlet was smaller than ours but he was a good deal more productive . . . except in the Winter when the permafrost precluded pretty much all out-door work. Coming to work with/for us in milder Ireland was better than sitting inside at home eating pork-fat and slugging down the wódka. We paid him a trifle over the minimum wage and he took home more actual folding money than he'd earn in the rest of the year from his hectare of strawberries. The following Summer I went, at his earnest request, to visit with his family.  It was interesting.  They were cash-poor but close to self-sufficient for food.  Every day, twice a day, Pani Tadek would go out into the field with two buckets: one to sit on and one to milk the cow into. It was a protocol familiar to many rural families in Ireland up until they joined the EEC in 1973. There were no economies of scale but the milk was good and you knew where it had been. You also knew your cow(s) intimately. A couple of weeks ago, I was talking to a dairying neighbour, and he said I could have a a few litres of milk at the price he got from Megacorp = 28c/lt just about 1/3 of what we pay in the shops.  Eating your own produce has leverage.

Yesterday I went to deepest South Kilkenny to see the future.  The owner, in Owning, of a Lely Astronaut A4 robotic milking machine was having an open day demonstration. You don't need to get your cheek up against the flank of your cows any more.  You don't need to get up at 0500hrs either.  You train your cows - takes from two days to two weeks - to form an orderly queue and amble into the machine's crush.  The front part has a trough with a taste of feed.  The other end has all the mad-robot machinery that you'd expect: little rotary brushes like in a car-wash to clean the udder, which is fairly likely to have been lying in a cow pat at some stage during the previous 12 hours and steam cleaners for the milking machinery.  You can watch the udder being played over by a criss-cross of lasers such as you might get in a shop's bar code-reader in order to get a 3-D image of the teat locations.  Then one by one the teat-cups orientate correctly >!whirr crrrk!< and engage each teat in turn >!ferloop!< and the machine starts to suck.  When the milk is stripped from the udder, the pump switches off, the teat-cups release and get steam cleaned, the front gates of the crush slap open and Daisy walks out and back to the field for more grass. The robot knows it's Daisy (or more likely A0245-01723) because she has a transponder on her collar.  She can't leave the shed through the electronic doors for fresh grass unless she has been recently milked.

There is a dairy-man, but he doesn't get chapped hands or cowpox.  His tool kit is more for cleaning the lines if they get blocked and cleaning the optical sensors so they read correctly and phoning the company when the machine goes wrong. This scales up. Once the computer knows which cow is in the A4, it can respond to the individual cow and to each quarter of her udder.  It's normal for the rear quarters to milk slower and less than the front quarters, and if the rear-left has been giving little over the previous seven milkings, that tells the machine to go easy there. Each of the four lines stops at what it senses is the right time. In the past you had to attach the milking device by hand but it would drop off at the end of the process . . . but drop off all together even though one teat might still be giving and another might be raw from dry-sucking.

If the cows are allowed to choose when to get milked they don't go twice a day anymore, they go, on average 2.5x - 3x a day.  This means that the milk is left at blood temperature for a shorter period and so potential mastitis pathogens like Staphylococcus aureus get flushed out before they can get a grip and so the somatic cell count SCC is lower. If the SCC (mainly white blood cells for fighting infection) is above a certain threshold, the milk will get rejected by the creamery as not fit for purpose. But there are indications that SCC is in fact higher in automatic milking systems perhaps because continual use doesn't allow the milking lines to be really thoroughly cleaned as they used to be after the morning and evening milking sessions. A lot of other milk qualities are measured in-flow & on-site: temperature, conductivity and colour for starters; and these, theoretically at least, allow some milk [colostrum, high SCC etc.] to be diverted from the bulk cold storage vessel.  They also allow, theoretically at least, some diagnostics to be done on the herd - who is getting mastitis, who is yielding the most.

There are questions
Q1. Why do cows have four teats when they generally give birth to a single calf? 
Q2. If let alone, will a cow settle into a routine to be milked at the same time each day?
Q3. Will those preferred milking times be scattered through 24 hours or are there peaks driven by, say, the hormone melatonin which has a daily cycle in concentration.

And the economics: statistics for Ireland 2014:
Cows: 1.14million
Dairy farmers: 17,000
Average herd size: 60 cows
Milk yield per cow 5,000 litres
Payment: 28c/lt
Gross payment: 60 x 5000 x 0.28 = €84,000
From the promotional material that was available yesterday it seems that a Lely A4 can had for €45/day or €16,000+ /year.  That's a chunk off the bottom line before even the electricity is switched on. Clearly it looks more profitable if your herd is bigger: the A4 and the shed to hold it is a fixed cost.  But you can't have an infinitely big herd because it takes 5 minutes for a cow to release all its milk.  If this is happening 3 times each cow is occupying the milking machine for 15min each day which says that the capacity for the machine is a little under 100 cows if they spread their occupancy evenly though the day.

Final question. If we are driving the dairy industry forward talking about efficiency, what are we keeping cows for at all at all?  Wouldn't it be better for the planet if we grew wheat and maize and lentils and ate them direct instead of feeding all those good things to cows for milk which the Chinese government doesn't want any more.  The PRC has just introduced a breast-feeding directive to all their mothers which threatens to collapse the global market in powdered milk.

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