Importance of using milk filter

Although commercially produced milk is processed, it remains entirely natural. And so is modern milk filtration. Today’s professional on-farm milk filtration uses entirely clean technology, based solely upon molecular size – it requires absolutely no additives. This clean technology helps farmers to produce milk of the highest quality and value.

Why using filtration
In on-farm milk filtration, a mechanical filter is used to separate the raw milk from any solid particles that may become suspended in it, before it reaches the bulk milk tank. This includes material such as dirt, manure, straw, hair, clots and insects – all of which can potentially cause problems for milking equipment and, of course, contaminate the bulk tank milk. But on-farm milk filtration is not a way to fix poor or unhygienic milking procedures. It is a best practice that plays an important role in good, holistic milking management.

The mechanical filtration method used to filter milk on the farm is also called barrier filtration. This is because the filter provides a porous physical barrier with highly specialized properties that enable the raw milk to be separated from the solids. The driving force of the filtration process is the difference in pressure between the two sides of the milk filter. When raw milk is pumped across the porous surface of the milk filter, a pressure difference either side of the filter is created. The pressure difference forces those elements that are smaller than the pore size of the milk filter (such as water, fat, proteins etc.) to pass through. Any elements that exceed the pore size of the milk filter (including straw, hair, insects, etc.) are unable to pass through and remain in the milk filter.

Why a good filtration
As well as maximizing the quality and value of milk, the installation of a good filtration system also protects both milking and cooling equipment from potentially harmful foreign particulates. This means that farmers benefit from filtration in two ways: they save money by maximizing the longevity and minimizing the maintenance of their milking equipment, and by producing milk of the highest possible quality they can command the best market price

Although milk is subsequently filtered at the milk plant, effective milk filtration on the farm plays an important role in:

• producing raw milk of the highest quality for the dairy company
• indicating the effectiveness of teat cleaning prior to milking
• identifying udder health problems (e.g. mastitis)
• identifying cow environment problems
• ensuring optimum plate cooler efficiency and hygiene.

The best place for installing filtration
With in-line milk filtering, it is important that the milk is filtered prior to cooling, because milk fat can pass through the filter more easily when the milk is warm. Filtering the milk prior to cooling also ensures that solids do not pass through to the cooling plate, as a build-up of sediment will not only compromise its heat-exchange efficiency, but also contribute to increased bacterial count in the bulk milk. In order to achieve optimal performance in on-farm filtration, the position of the milk filter is critical. Milk should always be filtered before it reaches the cooling system. Warm milk, within the temperature range of 36°–38°C (98°–100°F), can be filtered very efficiently as the milk fat can pass readily through the milk filter. When milk is cold however, between 0°–5°C (32°–40°F) for example, problems can arise. Milk fat in cold milk can block up disposable milk filters as it can not pass easily through the filter. This causes the milk flow through the filtering unit to be reduced to an unacceptable level.

What makes a good milk filter?
The role of on-farm milk filtration is to enable farmers to produce milk of the highest possible quality and value, as well as helping to protect the milking and cooling equipment. To ensure these demands are met efficiently, a good milk filter must possess certain physical properties. It is essential that the selected filter is the correct size and capacity to match the demands of the milking equipment and herd size. It must also be manufactured from highly uniform fabric, incorporating:

• high wet strength
• even pore size and distribution
• a strong seam
• dimensional stability
• food compliance.

Generally speaking, disposable milk filters should only ever be used for one milking session, and also for a limited duration. Depending on the milking equipment and herd size as well as the cleanliness of the animals (and especially their teats), disposable milk filters have a lifespan of approximately 8 hours, but should always be replaced after every milking session, regardless of the duration of that session. As long as these rules are observed, a milk filter will operate to its optimum potential, enabling the farmer to produce milk of the highest possible quality and value Inspection of the milk filter after milking has finished can provide an excellent guide to the herd’s udder health and to whether the teat preparation regime is adequate.

Attention
Any signs of mucous or clots on the milk filter indicate clinical mastitis in the herd.