How to clean a milking machine

People often assume that using a milking machine would be more work that milking by hand because of the time to clean the machine.  Actually its surprisingly quick to clean after milking.  And it only occasionally needs a more thorough clean.  Much of the information you find online about cleaning milking machines refers to large scale dairies that are milking a hundred or more cows a day.  If you are only milking one or two cows you can use a simpler and quicker process, and gentler chemicals, to keep your machine clean.

The only extra-large gloves at the supermarket were pink...

After every milking, as soon as possible, we tip out the milk (either for calves or for our consumption) and clean the milking machine.  The first step is a bucket of warm soapy water (not too hot, as steam can damage the vacuum pump, and hot water can actually make the milk solids more difficult to remove), which gets sucked through the milking cups and through the machine.  We use a few drops of dishwashing detergent in the water.  We then slosh this around inside the milk can and wipe off all the hoses before tipping out the soapy water.  The next step is a rinse with a bucket of warm water (also sucked through the milking cups).  Finally we leave the milk can upside-down to drain.  This is all that is necessary after twice daily milking and takes only about 10 minutes.  If the milking machine is cleaned immediately after the milk is tipped out, this amount of cleaning is sufficient.  When the milking machine is left unwashed for longer periods (even an hour or so, if other farm chores demand attention), minerals, fat and protein from the milk will gradually form deposits called "milk stone" inside the milking machine .

About once a week, or if we haven't used the machine for a while, we give it a more thorough clean with additional chemicals to remove milk stone deposits.  It is generally recommended to use a caustic or a caustic/chlorine detergent.  You can buy specialty chemicals from a dairy supplier, but you can usually also find something suitable in the supermarket cleaning isle.  Look for a cleaner that contains Sodium Hypochlorite and Sodium Hydroxide (with minimum fragrance as you don't want your milk to taste lemon-fresh).  Both of these are strong chemicals that can damage your skin and eyes, so make sure you wear gloves and glasses while cleaning your milking machine with these chemicals.

Acid milk stone remover (based on phosphoric or nitric acid) can also be used (for example).  This would need to be purchased from a dairy supplier.  Acid cleaners are better for hard water, which tends to react with caustic cleaners and reduce their effectiveness.  Again, this is a strong chemical and care should be taken to avoid contact with skin and eyes.  You can read all about the chemistry of different cleaners here.  Never combine ammonia with acid or chlorine cleaners, as you will cause a chemical reaction, if in doubt, its best to just use one cleaner at a time.

When we do the big clean, we usually also take the opportunity to pull off all the hoses and give them a clean with a bottle brush.  We have bought a range of sizes of bottle brush, and one small one is particularly useful for cleaning the long tube between the milking machine claw and the milk can, we tie it on a piece of bailing twine and pull it through the tube a few times (hot tip from Pete, the best way to get the twine all the way down the tube is running water or compressed air).  When you first get your milking machine, its a good idea to take it apart to find out which bits you can get into the clean properly.

The queue at milking time

Do you use a milking machine?  How do you clean it?

How to choose a milking machine

If you decide that you want to use a milking machine with your house cow you are going to need to choose between a few different options. Unfortunately, you get what you pay for, so don't be tempted by a cheaper model until you understand why its cheap. If you can, go and visit someone with a milking machine, or go and see a display model, so you understand what you are buying.

Many of the “mini” milking machines that you can buy are made for taking to shows for milking demonstrations. These are just small versions of the big milking machines found in commercial dairies. There are also some cheaper models made specifically for home milking, but we weren’t sure if they were the same quality.


Milking machine parts
Most milking machines consist of a claw, four teat cups (metal shells and rubber liners), a long milk tube, long pulsation tube, and a pulsator. The claw connects the short pulse tubes and short milk tubes from the teat cups to the long pulse tube and long milk tube. Claws are commonly made of stainless steel or plastic or both, ours is clear plastic, so we can see the milk coming out of the teat cups.

How does it work?
Milking machines use a continuous vacuum applied inside the soft liner of the teat cup to massage milk from the teat by creating a pressure difference across the teat canal. The vacuum also helps keep the teat cups attached to the cow. Air enters the pulsation chamber about once per second to allow the liner to collapse around the end of teat so that the milk is released from the teat into the cup. The four streams of milk from the teat cups are combined in the claw and flow to the collection vessel via a plastic tube. Essentially, it’s very similar to the action of squeezing and releasing used for hand-milking. 

 

How to use a milking machine
To operate the milking machine we turn it on and use the valve on the claw to seal the vacuum until it builds to 15 psi. Then we get down behind the cow and release the valve as we put the first teat cup on the first teat, this causes the vacuum to release until the teat cup is sealed around the teats. We quickly put the rest of the cups on the remaining teats and the vacuum holds them up while removing the milk. We watch the udder and milk flow until we’ve taken enough milk, then we use the valve to seal the vacuum again and gently remove all the cups in one movement. We then release the vacuum and turn off the machine at minimum vacuum (around 5 psi).

Cleaning the milking machine
After milking, the milking machine is cleaned very quickly and easily by sucking up a bucket of water with a little detergent and then a bucket of clean warm water. We were told by the manufacturer to use only warm water, not even the hot water from the tap, because any vapour sucked into the vacuum pump will damage the pump. The water is then tipped on the garden and the milking machine is left to dry out until the next milking session. We bought a BBQ cover to go over the milking machine to keep it clean and out of the sun (we keep it under porch on the side of our house).

How to choose a milking machine
Milking machines are expensive, our machine cost about $1700 in 2011, but you may also be able to find a cheaper one second-hand. Now that you have a better understanding of the milking machine, you will be able to compare the options available.

Here's a few things to consider:

• Hygiene – will you be able to quickly and easily clean the machine after milking?
• Durability and quality of materials – is the machine good quality? is it going to last?
• Moving parts and spare parts – generally moving parts tend to wear and may not last as long. Also, can you buy spare parts? Can you replace individual items that wear quickly like the teat cup inserts, or do you have to buy larger items, like the entire teat cup?
• Noise levels – all of the milking machines use an electric motor on the vacuum pump, it means that you have to connect to electricity and it is quite loud. Some models may be worse than others.
• Type of vacuum pump – different systems come with different pumps, you need to make sure that the pump will draw the required vacuum (at least 15 psi) and, if possible, find out the manufacturer. A cheap pump may not work reliably and may fail completely.
• Warranty – how long is the warranty valid? Does it cover all parts?

I’m not saying that you shouldn’t buy a cheaper system, but its important to understand why one system is cheaper than another. We decided we wanted to spend more on a quality system that will have spare parts available, and so far that has been a good decision for us. You may want to try a cheaper system and take your chances.

What do you think?  Do you use a milking machine?  How did you choose your system?

House cow milking schedule

Unless you really need every drop of milk from your cow, you can make life a lot easier for yourself by using the calf as a share-milker. Here is how it works.

Molly cow with her calf Ruby

A cow makes the most milk after she first calves and then her production gradually decreases. The amount of milk she makes will depend on her genetics, her health and the quality of her feed. We notice a huge difference in milk production if we have lush green grass in summer compared to dry grass in winter.

For the first few weeks after the calf is born, you leave the calf with the cow and milk the cow twice a day. The cow will gradually produce less milk and as the calf grows, it will drink more milk, so the amount you get at each milking will decrease. When you’re only getting 2 L at a time for a few days, you can cut back to milking once a day, either morning or afternoon, and the calf gets the rest. When you’re only getting 2 L a day, you can stop milking altogether. Now if you want milk, you separate the calf from the cow, usually overnight, and milk your cow in the morning. This provides plenty of milk for us for one week, so we milk once a week and calf gets the rest. This means we can go away for the weekend if we want to. It also means that we have 10 L of milk per day for only the first few weeks, and then gradually less until we only milk when we want to, so we’re not constantly trying to use up all that milk, but we can make cheese for a few weeks with the excess.

The easiest way to separate the cow and calf is to lead them both into a small pen where the calf will spend the night. You then lead the cow back out of the pen, she is usually tamer and quicker to follow a bucket of grain or hay than the calf. You give the calf some grain and hay and a bucket of water for the night. Don’t set up this pen too close to the house, because you will have to listen to them both crying all night! Gradually the calf will get used to having its grain too, and will follow you into the pen by itself. Make sure that there is no way that the calf could manage to get a sneaky drink through the fence, or you will be disappointed in the morning when your cow still has no milk!

Any questions about house cow milking schedules?  How do you manage your milking schedule?