Hunting thermos and bactos

Hunting thermos and bactos in the dairy


When you can't find the cause of bad thermoduric or bactoscan milk quality results, Paul Hurst of Dasco Daviesway has a guide to help farmers isolate the problem.

PROBLEM SOLVER: Dasco Daviesway chemist Paul Hurst on the job hunting for contaminants at a customer's dairy.

PROBLEM SOLVER: Dasco Daviesway chemist Paul Hurst on the job hunting for contaminants at a customer's dairy.

Paul Hurst is normally greeted by dairy farmers at their wit's ends.

The Daviesway DASCO industrial chemist spends his days finding the source of poor milk quality results, when the farmer and the processor's field staff find themselves at a loss.

And, there's almost always a great outcome.

"Probably 90 per cent of the time, I find the issue that would quite likely be causing the problem, and tell the farmer how to resolve it on the spot," Mr Hurst said.

However, he acknowledged that unsolved challenges were often frustrating, expensive, and time consuming for everyone.

"The reasons for high Thermoduric readings can be really hard to identify, and they often spike in the warmer months," he said.

"It can be something blindingly obvious like a build-up in the vat, the hot water service isn't as hot as it should be, or the rubberware is old and perhaps needs replacing.

"But, to be honest, the reality is that in 1-2pc of cases it is tough to isolate what may be causing these problems without professional help."

Unusually high readings could also often be one-off anomalies, which were usually resolved by a re-test.

"If you've been chugging along with bactos at 15,000 for weeks, months or even years, and then - all of a sudden - you get a 500,000 reading, generally either something's gone horribly wrong with your plant or there has been a failure with the testing procedure, or the sampling," Mr Hurst said.

"And, sometimes it just goes away by itself."

Thermodurics vs bactoscans

The approach to dealing with milk quality failures depended on the problem type.

Mr Hurst's hunt for thermoduric contamination usually came down to four things - the hot water temperature, cleanliness of the vat, condition of the rubberware, or pulsation/vacuum.

The water's temperature and hardness are checked, together with the detergent choice and dose rates.

The vat was the very next port of call.

"Even though it's been cooled to three or four degrees, milk is such a great substrate for microbial growth, that it doesn't take much of a soil level to rapidly increase contamination levels," Mr Hurst said.

Rubberware was the next suspect, including the milk lines, seals and joins.

Australian industry recommends inflations should be changed every 2500 milkings, and most dairies strictly adhere to the policy, Mr Hurst also understood the challenges within a tough season.

"Some farmers string that changeover out because it's a bit of a painful and sometimes expensive process to change this stuff," he said.

"But, that decision comes with a risk, because it potentially introduces another source of bacterial infection."

The vacuum and pulsation systems were another major breeding ground for potential thermodurics.

Testing time

Aside from the cost associated with quality failures, the time it takes to get results amplified the issue.

"Dealing with milk quality issues is always terribly frustrating for producers, particularly with thermodurics," he said.

"Because if we can't find it quickly, the test to narrow it down takes several days and we lose time, something no one has.

"And, while there is obviously a financial disadvantage for the producer if they drop out of the premium milk grade with their processor, I find it is often just as much about the sense of pride farmers take in producing a quality product.

"If they've tried everything and they are still getting a high reading, there is understandably an extreme sense of desperation and frustration."

When the bactoscan was the issue, Mr Hurst focused on the plant first, including the receival can, milk lines and the claw bowls.

"Our role exists to support producers, so that problems either don't happen, or we find and resolve them quickly," he said.

The story Hunting thermos and bactos first appeared on Stock & Land.


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