Wednesday, March 18, 2015

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.


house cow ebook: how to choose a milking machine


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. 

house cow ebook: how to choose a milking machine
 

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?

1 comment:

  1. Great post and something we will look at once we get to NZ

    ReplyDelete

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