Using dynamic testing to assess a milk parlour’s performance and resolving issues associated with over-milking and poor milk flow can improve udder health, a study on Welsh dairy farms has found.

Farming Connect worked with four dairy farms to examine the impact of milking parlour dynamic testing on udder health.

Whilst an annual statutory static test is compulsory, dynamic testing is only used by around 5 per cent of dairy farms, says vet Dr Sotirios Karvountzis, of Mendip Vets, who led the study.

A dynamic parlour test is a way of assessing the plant during the milking process and it will identify ways in which it can be improved and made more efficient.

It charts activity during milking and checks include udder preparation for good milk flow, milk liner fit, milk flow away from the teat-end and over-milking and can act as an early warning system to identify stress factors that, if left unchecked, encourage full scale udder health issues.

During the 12-month project, multiple problems were identified during testing and interventions were introduced on the four farms to improve the operation of the milking plants and the milking routine.

The result was a positive change in udder health, says Dr Karvountzis.

“There was strong evidence across the trial farms that for every package of interventions applied in the herd, the average bulk tank somatic cell counts reduced by 3.86 x 1,000/ml,’’ he says.

The project, funded by the European Innovation Partnership (EIP) in Wales, involved bimonthly visits to each farm to carry out a dynamic test, teat score and teat measure.

There was strong evidence that for every series of interventions applied as a result of those measures, the incidence of overmilking in the herd reduced by 21 per cent; interventions included checking the ACR diaphragm and the ACR cut-off milk flow.

Over-milking is one of the primary mechanisms of damage to the teat end, which in turn is one of the many defence barriers of the udder to mammary infection, says Dr Karvountzis.

“It is a common misconception that automation comes with greater efficiency but the project identified that a number of ACR were not functioning properly, resulting in overmilking of the quarter.’’

Dr Karvountzis says the primary contributor in the malfunction of the ACR is the lack of testing in those devices.

The study also showed that interventions advised as a result of the dynamic testing reduced the incidence of poor milk flow away from the teat by 42 per cent; these included removing constrictions to the milk pipes relating to backflush, particularly in high milk line parlours during periods of high milk yields to improve milk flow away from the teat, removing the long milk pipe constrictions or increasing the vacuum reserve.

The frequency of inadequate milk plant pulsation reduced by 48 per cent with interventions including checking and remedying individual pulsator malfunction.

Over time, pulsators and pulsation tubes become contaminated with dust and slime, reducing their effectiveness in transporting vacuum in the various parts of the milk plant, says Dr Karvountzis.

It was a finding of this project, that once the pulsators and pulsation pipes were cleaned or replaced, the subsequent improvements in those parts were evident at the next dynamic test, he adds.

“This should also raise an important point about when these parts of the milk machine be regularly checked, in order to detect early any deterioration of their performance.

“The obligatory annual static test of the milk plant is the obvious area that may be proposed here, but in my experience these checks are not always carried out.’’