Assessing Milking Parlour Suitability For Your Herd

Herd sizes have continued to grow in Northern Ireland. The average herd size is now in excess of 70 cows. Almost half of the cows in Northern Ireland are in herds over 100 cows. This has increased markedly in recent years. (Table1)

Against this background many farmers are milking in unsuitable parlours and need to invest in a new parlour to suit their needs. With high labour costs, even problems accessing labour, and higher yielding cows, the recent trend has been to install milking parlours with a greater number of units to be handled by one operator.

Installing a new parlour is an expensive, once in a generation investment and should be planned carefully.

Take the common example of a father and son milking 120 cows in a parlour that has evolved from a 6 point herringbone originally commissioned for 40 cows. The stall work is old and the building cannot accommodate further renovation beyond the current 8 points: 16 stall arrangement.

To remain in business they need to invest in a new parlour. What size is the new parlour they will need?

Parlours should be sized to complete the actual milking in 1hour 30 minutes and should allow for future herd expansion.

It is possible to milk seven rows of cows through a medium sized parlour each hour. Consequently with reasonable efficiency six rows can be milked through a large parlour in an hour.

More units, more operators or automation can be used to maintain the speed of the operation. With Automatic Cow Identification, the operator need only prepare the cows and place clusters. Auto Id allows automation of meal feeding and milk recording

Doubled up parlours reduce the number of stalls required but increase the number of units, this adds to the initial expense and running / maintenance costs. The major disadvantage is that this extra cost is not reflected in the performance.

Table 2 shows the number of cows that can be milked by various swing over or equivalent doubled up parlours. A herd of 120 cows milked in 1hour 30 minutes will need 12 milking points in a swing over configuration or 20 milking points in a doubled up parlour.

Table 3 details the father and son options to milk the current herd of 120 cows  or allowing for expansion to 180 cows

Maximising the number of milking units has always been seen as the simplest solution to reducing time spent milking. However as parlour lengths’ increase to accommodate greater numbers of milking points it has been necessary to change the stance of the cow in herringbone arrangements. Thus the traditional 30 degree parlour has been largely replaced in new installations by more steeply cranking the cows. Greater numbers of cows are stalled in shorter parlours as stall work moves through 50, 70, 80 and ultimately 90 degrees.

(Table 4) The consequence for the parlour building is that pit remains relatively short but the overall parlour width increases.

In addition to parlour type and output, there are other key considerations in design that affect performance;

The above site shows work in progress where an existing parlour is being replaced on a brown site. Central to the shed is the parlour building with pit and internal walls already constructed to accommodate a 28:28 50 degree low level parlour.

At the bottom of the picture use is being made of an existing collection yard. When work is complete a rectangular yard directly behind the parlour will provide collection for all the cows during milking.

To the left of the parlour is the cow exit and drafting area. The central slat covered channel marks the position of a race returning cows to their cubicles. A three way drafting gate can be used to retain cows that require specific attention.

The smooth flow of cows to the milking parlour is essential for fast milking. A rectangular collection yard in line with the parlour is best for loading cows. It should be sized to house all the cows in the herd, with a yard space of 1.3m² per cow.

A clear, well lit approach with a slight upward incline promotes cow entry. As collection yards are used throughout the year slats are the most appropriate for ease of cleaning and reducing the soiling of clusters with manure from cows’ feet.

As significant amounts of concentrates are now fed outside the parlour there is an increased need for backing gates. A manually operated gate fitted in the collection yard at one-third of it’s length from the parlour, to control cow movement as milking progresses. Various types of automated backing gates have been fitted locally to reduce yard size. These are normally suspended from an overhead gantry and can operate to bring forward follow on batches.

The milking parlour exit area should be sized according to the number of stalls in the parlour to allow quick change over of batches. It is important to have a system for drafting individual cows as they leave the parlour.

Drafting at the parlour exit can be as simple as a hinged gate and compressed air ram at the cow exit. In the shedding position cows for insemination, pregnancy checks, vaccinations, or other labour intensive tasks can be diverted from the main group as they leave the parlour.

Where there is auto id available, cows can be diverted automatically in three different directions according to management needs with no labour input required. Cows are accurately sorted and normal cow flows are not disrupted. It provides gentle cow treatment and maximum cow traffic speed away from the parlour.

Finally the ultimate aim is to get value for your investment. Plan to allow for milking an expanded herd in no more than 1 hour 30 mins. Make maximum use of your site to facilitate drafting cows.

This is a once in a generation investment, proper planning will prevent costly mistakes being made.