How our milk is tested for antibiotics

Milk testing

Yesterday, I explained why and how we use antibiotics to treat a cow who falls ill in the herd, together with what we do to make sure no antibiotics get in the milk that leaves the farm.

In this post, Fonterra’s quality manager for milk supply, Sarah Carter, answered a few questions about how the milk is screened for antibiotics by the milk factory.

MMM: Why is it important to keep antibiotics out of milk?
SC: Customers, consumers and markets have very clear requirements that dairy products are to be free of antibiotic residues. The two main reasons for this are: the risk of causing allergic reactions in humans (e.g. from penicillin), and the concern about a build-up of antibiotic resistance as a result of consumption of dairy products containing low levels of antibiotics.

MMM: What does the law say about antibiotics in milk?
SC: In Australia, the Australian Pesticides & Veterinary Medicines Authority (APVMA) assesses agricultural and veterinary chemicals, such as cattle antibiotics, as being suitable and safe for use. They set Maximum Residue Limits (MRLs) after undertaking a thorough evaluation, including a dietary exposure assessment. These MRLs apply to domestically-produced foods, and are set well below the level at which any residues would be harmful to human health. The MRLs are set at levels which are not likely to be exceeded if the approved label instructions on the antibiotic product are correctly followed.

MMM: How and when is the milk tested?
SC: Most, if not all, dairy companies test tankers of milk for antibiotics prior to unloading at the factory, to avoid any contaminated milk entering the supply chain.

A number of dairy companies will also have the individual farm milk samples randomly tested during each month to further discourage farmers from taking a risk and allowing a vat-load of milk to be collected where perhaps a treated cow had been accidentally milked.

At Fonterra, we have both these measures in places – we are very clear that to maintain and build the market relevance of our dairy products, dilution with milk from other farms in the tanker is not the solution.

MMM: How sensitive are the tests?
SC: There is quite a wide range of tests available to detect antibiotics in milk, and the detection limits for antibiotics vary between tests. All dairy companies have their antibiotic testing procedures audited by the relevant state dairy regulatory authority (such as Dairy Food Safety Victoria) to ensure that their chosen test method is suitable for purpose and based on a risk assessment.

Different test methods will have different sensitivities to the various active ingredients found in commonly-used antibiotics – there is a technical information note available on the DFSV website which lists the common tests and their detection limits.

MMM: What happens if antibiotic residues are detected?
SC: If antibiotics are detected at the tanker level (prior to unloading into the factory), the entire tanker load is rejected and the milk disposed of (e.g. via the factory environmental management system).

Traceback testing is undertaken on all farms on that tanker load, to identify the source of the issue. We then undertake an on-farm investigation to get to the root cause of the problem and put measures in place to ensure it doesn’t happen again. All antibiotic-positive tankers must be reported to the state dairy regulatory authority, and followed up with a report stating the findings of the on-farm investigation.

If antibiotics are detected on a random farm sample test, we again undertake the on-farm investigation to help the farmer identify what went wrong. We also undertake a trace-forward to check for any impacts to products manufactured from this milk.

Farmers receive a penalty for supplying antibiotic-contaminated milk, and this penalty increases significantly if it happens again – fortunately, repeat offenders are incredibly rare, which demonstrates that the investigation and corrective action process achieves what it’s meant to.

At Fonterra we also encourage our farmers to get in touch with our SupportCrew milk quality specialists, who can assist farmers with advice and support to minimise the risk of mastitis in the first place.

Thanks Sarah!

Mastitis, antibiotics and milk

Why do we use antibiotics on our farm? Very simply, because despite everything we do to look after their well being, cows, just like people, sometimes fall ill and need antibiotics to get better.

It’s very rare that any of our 260 milking cows become lame with an infection while digestive problems are almost unheard of here and, in any case, do not require antibiotics.

The number one illness we treat on our farm is mastitis. If you’ve breastfed a baby yourself, there’s a fair chance you’ve experienced mastitis. In both cows and women, the symptoms include swelling, warmth and redness for light cases. Nasty cases bring flu-like symptoms that, in cows, can progress to become extremely serious.

How we prevent mastitis
So, how do we reduce the incidence of mastitis on the farm? We begin even before the calf is conceived by selecting sires whose daughters show a naturally lower susceptibility to mastitis.

At the same time, we minimise the risk of infection by keeping the cows and their environment as clean as possible. Tracks are maintained so there’s less mud around to flick onto teats and cows are happy to walk straight to their grassy paddocks rather than spending their rest times on mucky surfaces.

Cows resting in the paddock

Cows resting in the paddock after milking

The cows are well fed with a carefully balanced diet that is mostly grass and we treat the cows with care to minimise stress. It’s a slow, gentle walk to the milking shed, there’s no shouting and if I see one of our cows run, there’d better be a good explanation!

The hygiene of the dairy is important, too. We clean any dirty teats before the milking machine cups go on and spray them afterwards with a mix of iodine and glycerine to disinfect and protect them. We also routinely test the milking machines to make sure they are gentle and effective.

And we’re vigilant. Not surprisingly, when you spend hours every day with the cows’ udders at face level, you notice a sore cow quite quickly. A sore cow is an unhappy cow and an unhappy cow is an unhappy milker, too. Everyone who milks in the dairy has been specially trained at a “Cups On, Cups Off” course to look for mastitis and put top priority on the comfort of our cows.

Sometimes, cows have sub-clinical infections that don’t show any symptoms, so every few weeks, we collect samples of milk from every cow and have them analysed at the local herd test centre lab.

It’s a lot of work but it’s important work. The comfort of the cows is our number one priority and there are implications for the quality of the milk, too. If there is too much mastitis in the herd, our milk has a shorter shelf life.

One thing we don’t do, however, is include antibiotics in the cows’ feed. Routine antibiotic use is not legal and would mean that none of our milk would be useable.

Treating mastitis
When we find a cow with mastitis, we don’t wait to see whether she goes downhill, we treat her immediately with the medicine prescribed by (and only available from) our vets to help her recover fast. Antibiotics help the cow feel better in a day and we keep on milking her so that her udder is well drained and kept as soft as possible.

Making sure milk is free from antibiotic residues
The milk we collect from a treated cow is tipped out until there is no risk of antibiotic residues in the milk. The antibiotics come with quite precise details of how long they remain in meat and milk. It’s critical information because nobody wants food laced with antibiotics, especially those with life-threatening allergies.

As precautionary measures, we:

  • paint the cow’s udder red as a warning to everyone in the dairy that she either needs more treatment or to have her milk disposed of,
  • write her treatment needs and the time her milk needs to be withheld from the vat on a whiteboard in the dairy for all to see, and
  • record all her treatment details in a quality and treatment register.

After she has finished a course of treatment, we check the cow again to be sure the infection has cleared up.

Testing for antibiotic residues
Even with all these protocols, it’s good to know that if milk contaminated with antibiotics somehow got into the vat, there are more safeguards in place. In the next post, a guest from milk processor, Fonterra, will explain how they test our milk for antibiotics.

The bottom line
Our cows live good, healthy lives and rarely fall ill but when they do get sick, we give them the best treatment available straight away. For people and animals alike, antibiotics are our last line of defence against misery and death, so we use them only when really needed and then with great care. And I don’t want to go back to a world without them.

The politics of Easter eggs

kids_spring06_egg_cow.jpg

Easter eggs are now a political football with Animals Australia is using them as an opportunity to spread the word – and the guilt – about eating food laced with dairy cruelty.

At the same time, the Australian Raw Milk Movement is preaching the gospel of Vicki Jones, the woman behind the recalled milk associated with the death of a toddler. Apparently cows being treated with antibiotics when they fall ill are “paying the price” for the milk we conventional farmers provide. Better to assume no animal on an organic farm ever falls ill (or can simply “disappear” if she doesn’t respond to a massage with magic cream).

It disheartens me tremendously that treating a sick animal with the best medicine available can be dressed up as some form of cruelty but I think I’d better get used to it fast. Why? Because there are two movements gathering pace in Australia: “food fear farming” and “orthorexia nervosa”.

Food fear farming for product differentiation
You can make money from frightening mums and dads in the supermarket.

Milk that contains added permeate (which is an ugly name for milk’s natural sugars and vitamins), is pasteurised, comes from cows fed some grain or is not organic can be made scary. And non-scary milk gets a lift!

This is a basic marketing principle called “product differentiation” and is used by marketers in every consumer goods category from toilet paper to life insurance to gain market share or justify a higher price.

“When we were conventional dairy farmers I felt so frustrated at being powerless in the industry but now we are price setters and have security. It actually feels like we are running a business.”
– Vicki Jones, raw milk farmer, The Weekly Times, 17 September 2014

The reality is that as the margins around milk become tighter and tighter, we can expect to see increasingly desperate attempts to differentiate milk brands from the mainstream.

Orthorexia nervosa
Nutrition lecturer at UNSW Australia, Rebecca Charlotte Reynolds, wrote in The Conversation recently, that:

Orthorexia nervosa, the “health food eating disorder”, gets its name from the Greek word ortho, meaning straight, proper or correct. This exaggerated focus on food can be seen today in some people who follow lifestyle movements such as “raw”, “clean” and “paleo”.

Of course, food-centric righteousness comes in many forms and I’m watching as animal activists and food activists come together.

That quest for purity teamed with the need to differentiate what is otherwise a commodity product is perfect for farmers and food marketers desperate to make a dollar. Sadly, it’s often at the expense of everyday farmers and shoppers like you and me. And, if they could have their way preventing the use of basic medicines like antibiotics, the wellbeing of innocent cows.

Antibiotics in milk keeps us up at night

Yesterday I made a phone call that could cost our family thousands of dollars.

It had all started during the routine rounding up for the afternoon milking. I love rounding up. It’s a great time to chill out, enjoy the scenery, check the fences and troughs and admire the cows. I take my little red book and write down the numbers of any cows that need attention and have a look at the pastures to check the cows got the perfect amount of grass.

While scanning the herd, my eye rested on a young black cow with a ridiculously round belly and very little milk. I knew her. Only two weeks ago, I’d had her preg tested and sent on her annual holiday. On Sunday, I’d decided she was closer to calving than first thought and put her in the calving paddock.

But here she was with the milkers. After freezing in my tracks for a moment and taking a deep breath, I turned around and rushed to the house to start making phone calls. The first phone call was to our field officer at the co-op, Gregor.

“Gregor, I’ve just seen a cow in the herd who must have been milked this morning during her withhold period. What happens now?”

The problem was that this cow, 1216, had been treated with an antibiotic to cure and prevent mastitis during the critical calving period. That morning, Clarkie had found a lot of white “stuff” in one of the filters after milking. Now that I’d seen her, I knew it must have been teat seal – which is used to keep nasty bugs out of her teats, while holding in the antibiotics. The $64,000,000 question was: had the automatic cup removers taken the milking machines off in time to prevent antibiotics reaching the vat?

If there was even a trace of antibiotics in there, a whole day’s milk would have to be poured down the drain.

The only thing to do was take a sample from the vat into the local vet centre to be tested, a process which could take up to four hours. When I got back outside, Clarkie had taken over rounding up, wondering what on earth I was up to. Once I explained, he sent the cows back to the paddock while I shot off to town with a sick stomach and one of Zoe’s water bottles filled to the brim with milk.

On the way home after school, I explained to Zoe what it all meant, including the implications of pouring the milk down the drain and the implications of not being honest with Murray Goulburn about spotting the cow in the first place. It was a quiet trip and a long, long few hours while we waited to hear from vet Amy who’d stayed back late to test our sample. But our patience was finally rewarded with a negative result – four hours after normal milking time and at the end of an already very long working day, Clarkie fired up the machines again and topped up the vat with the day’s milk.

I am so appreciative of the support from Clarkie, Gregor and Amy during this crisis on old Macdonald’s farm. And, today, I am off to buy another electric fence unit that will be dedicated to the calving paddock.

Have you seen a cow with blood all over her udder?

When Zoe’s city cousins came to visit the other day, they were horrified to see one of our cows with a crimson udder. “Oh my God, she’s bleeding!” cried one of the boys.

Painted Picasso Cow

Painted but not quite like this Picasso Cow (thanks to Libby Lambert for the pic!)

“No, it’s okay, she’s just painted,” laughed Zoe.

They were almost as astonished by Zoe’s reply as they were horrified by the thought of all the bleeding.

Why do dairy farmers paint cows?
We buy paint for cows in bulk. We use orange to denote a freshly calved cow still producing colostrum, blue when we want to keep an eye on a cow for some reason, red when she’s undergoing treatment and green once the treatment is complete.

The red paint is a warning to everyone who milks the cow – first, she needs treatment and, second, her milk must not enter the vat. Instead, it is collected in a separate bucket and discarded. Thankfully, Australia’s food safety regulations are very stringent and no trace of antibiotics may be present in milk.

You might also see cow’s backbones right near their tails painted different colours. But that’s a story for mating season.