1. BUCKET PLANT
The bucket plant is the simplest form of milking installation and is the most commonly used amounst smaller farmers. It consists of one or more bucket units and a vacuum line. A bucket unit consists of a cluster, pulsator, bucket and connecting tubes. A vacuum unit consists of a vacuum pump, a vacuum line fitted with taps, a regulator and vacuum gauge. During milking, the bucket is under vacuum and milk is drawn into the bucket from the milking cluster attached to the cow’s udder. After each cow is milked, the milk is poured into a cooler and the cold milk is collected in a milk can. The buckets used are made from stainless steel and hold 20 litres of milk, and the milk cans hold 45 litres.
Figure 1: The main components of a 2-bucket milking plant
Figure 2: The different componrents of a milking bucket
Figure 3: The componets of milking vacuum line
Cold water is fed in at the bottom of the cooler and comes out at the top. Milk is poured into the container above the cooler and runs slowly over the cooling surface. This method will cool milk to within 1 – 2° of the water temperature, but cooling must be done in a clean, enclosed dairy, free from flies and dust. The water from the cooler can be collected into a tank and used for washing down the cowshed.
By using a bucket plant, one operator can do the work of three hand milkers and produce better and cleaner milk. In fact, a highly skilled operator can work up to 4 buckets himself and can milk up to 50 cows himself. A bucket plant is used in small herds where the cows are brought into a cowshed, tied up, fed and milked. The
dairy where the milk is cooled and stored must be Source: thebutterflybalcony.blogspot
separated from the cowshed. A plan of a small cowshed and dairy is shown below. Each standing holds 2 cows and is 2 metres wide. The shed holds 26 cows for feeding and milking.
Figure 5: A diagram of a milking parlour
2. PIPELINE MILKING
A pipeline installation makes the work of milking easier and faster by avoiding having to change, carry and empty buckets of milk. A milk pipeline and milk receiving jar can be fitted in a cowshed and the operator carries only the sets of milk clusters from one cow to the next. A good operator can milk more cows in a shorter time than by using a bucket plant.
Figure 6: Shows the receiving jar with a vacuum line and a milk line
Milk receiving jar fixed in the dairy. Milk from the pipeline runs into the jar and is then trickled over a surface cooler and into the milk can, or it is run into a refrigerated cooling and storage tank.
Figure 7: Diagram of a milk pipeline system in operation
Figure 8 and 9: A cowshed suitable for milk pipline (left) and Flow of milk to receiving jar (right)
3. MILKING PARLOURS
Figure 10: A typical milking parlour
These are suitable for large herds of cows and have the advantage of being cheaper and easier to install than building large cow sheds. In the colder climates where cows have to be kept inside during the Winter, many herds are kept loose in large barns and milked in a milking parlour. Modern milking parlours are based on the pipeline system, and are divided into 2 main types; those where the operator is on the same level as the cows, and those where the operator stands in a pit, usually 0,75 to 0,9 metres deep so that the cows’ udders are at face level. This saving in walking and bending reduces operator fatigue.
On the left is the plan of an abreast parlour where the operator is on the same level as the cows. There are 3 milking units, and while one cow is being milked, the other cow is being washed and fed concentrate. The machine is taken off the milked cow, and transferred to the prepared cow, and the milked cow is allowed out into the collecting yard.
Figure 11: Cows in milk
Figure 12 and 13: A tandem parlour (left) and a herringbone parlour (right)
Figure 14: Milkflow in a herringbone parlour
Figure 15: A herringbone parlour in action
These parlours are available in sizes from 3m – 3m to 12m – 12m. Cows are let into the parlour, and while those on one side are being milked, the other side is being washed and prepared. The milked cows are let out and replaced, while those on the other side are being milked. This is the most common type of modern milking parlour because of the saving in labour, time and effort.
Figure 16 and 17: Milk clusters are cleaned by circulating water, detergent and chemical sterilisersaround the milk clusters, pipes and receiving jars
Figure 18 and 19: A rotary parlour (left) and a milkline in a rotary parlour (right)
Figure 20: A rotary Diry parlour in action
In this system the cows are milked while they travel slowly on a revolving platform. The operator puts the milking cluster onto the cow and when she has completed her circuit, he removes the milking cluster, the cow walks out and is replaced by another cow. Time taken for the platform to revolve can be varied from 7 to 12 minutes according to the breed of cow and milk yields. The whole operation including the feeding of concentrate can be controlled from the control panel in the centre of the pit, and each cow can be observed during the time she is being milked.
Figure 21 and 22: Milk Storage Tank (left) and a Cream Separator (right)
Source: image.made-in-china. Source: pladot