Robots, Rotaries and Relationships

There is nothing that quite connects man and beast like hand milking. The rhythm of mornings and evenings, crouched beside the flank of a cow, the skilful opening and closing of fingers around a fleshy teat, the smell of warm, fresh milk, and the tinny sound of the stream hitting the side of the pail.

There was a time when these sensations were widespread amongst people. Now, it's only in the developing world where hand milking is still widely practised. I consider myself lucky - in my childhood I hand-milked our pet goats, and sometimes Buttercup, our Jersey cow, though for her we mainly relied on a basic milking machine.

This blog is about people and cows and their relationship - especially dairy cows. The advent of the milking machine has influenced that relationship hugely. It has allowed us to keep larger herds, which in turn has changed how we relate to cows as individuals. And it has broken the intimate connection I described above.

Recently, my dad handed me his copy of The History of Mechanical Milking 1900-1950, published by Vaccar, one of the first manufacturers of milking machines. I'd say it's essential reading for anyone! My dad had a copy because he used to work closely with Vaccar when they were based in Derby, where my grandfather (and later my father) had a factory making the steam boilers used to disinfect early milking equipment.

An early field milking machine, 1910. Copied from my dad's Vaccar sales booklet from the 1950s

Reading the booklet, and seeing the lovely photographs within, it struck me just how fast the adoption of machine milking occurred - and just how fast it has continued to evolve. One of the initial drivers, it appears, was the shortage of human labour in the two Great Wars. I wonder, too, if another driver was simply that cows milked out better with a machine. Machines are very predictable, and cows like predictability. Recently, on a large farm I work with, I noticed that cows walked onto the rotary milking parlour much more readily once a robotic teat cleaner had replaced the person normally responsible for teat preparation, ahead of a second person a few feet further on who attached the milking clusters. The robotic arm moved exactly the same way for every cow, and once they were accustomed to it, the cows had nothing to be uncertain about. Robots don't shout, either - an unfortunately common trait of people when they get frustrated with cows walking too slowly onto the rotary platform.

Fully automated milking systems - "robots", as they're usually called - have become very common over the past 20 years or so. When I was a younger vet, I first witnessed how transformative these were for small family farms in the Netherlands, and since then their uptake in Britain has been just as popular. One robot comfortably milks around 50 cows. On such a system, cows choose when they're milked, and a typical cow will be milked just over three times a day, dropping off as she gets further into her lactation (i.e. further from when she last had a calf). A typical milking takes around five minutes - add a few more for teat preparation and for the robot to attach the cups. So, doing the maths: 50 cows, milked three times a day, at eight minutes a time, comes to 1,200 minutes, or 20 hours. The other four hours of the day are used for automatic washing and disinfection of the machine, plus a little "down time" (even robots appreciate forty winks occasionally!). This simple arithmetic is a limiting factor for how fully robotic milking works - cows must have access to the robot pretty much all day long and it's one reason why this system tends to favour fully housed and smaller herds. This differs from traditional milking parlours, where cows are milked two or three times a day and can be far away - in fields or a shed - in between times. A milking shift in the UK is usually around two to three hours for the operators, but the cows themselves need only to be brought to the parlour for the short while it takes their group to be milked - ideally no more than around 30 minutes - before returning to their beds, their feed, or their field.

A bit more milking maths

Modern dairying runs on arithmetic as much as it does on stockmanship, and it's worth elaborating on this a little - because it's not something most people outside dairy farming would ever think to consider.

The fastest a cluster can be attached to a cow's four teats is six seconds. One person applying clusters at this rate could, in theory at least, milk up to 600 cows an hour. The fastest milking of all is done on a rotary, or carousel-type, parlour. Here, cows walk onto a platform like a fairground carousel; it rotates slowly while the milking machine is applied, and the cow walks off after a complete rotation, machine automatically removed.

Applying the eight-minute-per-milking rule, the most efficient platforms complete a rotation every eight minutes. Applying the six-second attachment rule, that means the most efficient farms can milk 80 cows per rotation - which is the size of the largest rotary parlours in use. It means a group of 400 cows can, in theory, leave their shed, all be milked, and have the last one heading back to her bed or field within 40 minutes.

A modern rotary milking parlour - this one is on a farm I visited in Estonia last year, but similar set-ups are commonplace across UK. The openings at the far end of the photo are where cows walk on and off the carousel. This platform is rotating anti-clockwise. There is an operator towards the top left of the photo (not in shot, but around 10 cows along from the entry-point) who will be applying the clusters as the cows move past them. Just before the cows have completed a full revolution, the clusters will automatically fall away. The cows you see in the foreground are in mid-flow, probably about 4-5 minutes into their milking, and you can see the milk and vacuum pipes between their back legs which supply the clusters. Milking should be very pleasurable for the cow: if you stood right in the middle of this carousel you'd be surrounded by sixty bovine heads contentedly chewing their cuds as they slowly move around you - it is quite an experience!

Scale these numbers back a bit for smaller rotary parlours, and for "herringbone" parlours, where cows walk into the parlour in a row, are all milked simultaneously, then walk out again once the slowest cow has finished. A row (or side) typically holds anything from 5 to 50 cows. People are still very much involved in the milking process, as a human can still attach a cluster far faster than a robot - I think we're a few years away yet from robotic cluster attachment in a conventional parlour. At the moment, fully automated systems are mainly confined to smaller family farms. Larger herds tend to have conventional herringbone or rotary parlours where a larger numbers of cows can be milked quickly.

A herringbone parlour - this is the most conventional type seen in UK farms today. A row of cows walks in - anything from 5 cows to 50 cows, depending on the length of the parlour - and operators stand in the pit, preparing teats and applying the clusters (milking units). It takes a little while to apply the clusters to the whole line of cows (although the longer parlours have more operators), and they can only walk out once the slowest cow has finished her milking. You get very familiar with the back end of the cow - but there isn't so much opportunity for a meaningful conversation with them or to scratch their heads! It isn't unusual for a farmer to spend six hours of each day in the milking pit - which can put considerable time pressure on other aspects of their job.

A wide-angled view of a housed herd with two milking robots ("voluntary milking system"). The red stalls are the actual milking robots and the cows visit these of their own accord whenever they feel ready to be milked. They get a tasty feed of cow nuts here too - which is no doubt an added incentive! The cows on this farm remain in their shed all the time, which is the most usual way for robot herds, but they can have quite a lot of human contact as the farmer will often be working amongst them throughout the day, for example cleaning the beds, administering any treatments and serving cows on heat. One person can comfortably look after 100 cows with two robotic milking stations, as their time is not taken up with the actual milking process.

I hope you're not put off by my getting all technical on you. I wanted to show how arithmetic, efficiency and practicality all govern the way we milk cows - and, in turn, our evolving relationship with them. We might legitimately ask how the cows feel about all of this. One interesting observation of mine is that a herd of housed cows milked by robots is often noticeably quieter to walk amongst than a herd of housed cows milked by people in a parlour. The simple explanation is that they're more used to people walking amongst them. For traditionally milked cows, no one walks amongst them during the day, since their beds are cleaned during milking time when they're out of the shed; their only real human contact comes at milking - and that can be the briefest of moments, with an operator standing beneath them, out of sight or smell, attaching the machine. Contrast that with people walking amongst the cows to clean beds, stroking a nose here and there, scratching a tail head, conversing at eye level. So here's a case where mechanisation might, full circle, be allowing a greater bond to develop.

There are many ways to keep dairy cows - housed, grazing, seasonally block-calving or year-round calving, in large groups or small, organically fed, high-yielding or low-yielding, in hot climates or cold, with or without calf contact, milked once a day, twice a day, three times a day, or voluntarily by robot. There isn't a right or wrong. I've worked with all of these systems - we have the full gamut of them here in the UK - and it's one reason I never get bored of my job. My experience is that every one of these systems can be done very well - but every one can be done badly, too. However we look after our dairy cows, paying attention to the cow-human relationship is critical. I never want us to lose touch with the magic of that close bond, built as it is on thousands of years of evolution.