The Myth: Liners - if they fit the machine, they must fit my cows...
Busted: Yeah right!
Choosing the correct liner can have a dramatic effect on milking performance and udder health. It is definitely not a case of one liner fits all.
Selecting the correct liner to suit your cows is critical. Liner design is continually evolving, with different shapes, sizes and materials being promoted.
The manufacturers’ aim, regardless of material, is to produce a ‘perfect liner’ that is shaped to:
- provide an airtight seal at both ends of the shell
- provide a mouthpiece and barrel of a size that will fit on a range of teat shapes and sizes
- minimise liner slips and cluster fall-off
- allow for a quick and complete milk out, while minimising teat congestion, discomfort and injury
- be easily cleaned.
Many variables in a herd and milking plant determine a liner’s performance – from teat size and shape to speed of let-down, vacuum levels, pulsation rates and ratios, weather conditions etc.
Liners also have a limited life. The reality is, the ‘perfect one liner that fits all’ has yet to be developed and is not likely to be seen on shelves any time soon.
Therefore, the aim should be to find a liner that best fits the plant and herd. A liner that provides:
The teat should look much the same before and after milking. Teat distortion, pinching or wedging of the teat end, a painful-looking ring round the top of the teat or a change in colour to blue/purple, indicate possible liner problems. Uncomfortable cows are likely to be restless, stamp their feet and/or kick the clusters off – particularly heifers.
Clean milk out
The udder should collapse and be wrinkled-looking after milking. A fleshy looking udder shows the liner is leaving lots of 'strippings'. This may affect milk production and/or somatic cell counts, depending on the severity of the problem.
Stability on the teat
The liner should sit firmly on the teat without slipping down and squawking, or letting air in around the top. Liner slip is upsetting to the cow, annoying to the milker and slows the milking rate. Accept no more than five slips per 100 cows.
Good milking speed
Aim for all cows (apart from those with teat damage or deformed udders) to be milked out within a seven to nine minute row time.
The only real way to identify which liner is best for a herd is to trial them and monitor performance on a few clusters, before committing to a complete liner change.
If unable to find a liner that satisfies the above, then consider different liners for front and back quarters. You may even need a change in the milking plant componentry to achieve peak performance.
by Chris Leach, DairyNZ Developer, animal husbandry
This article was originally published in Inside Dairy March 2014