When taking milk samples, large pottles usually mean you collect too much milk and risk contaminating the sample. In this image, each pottle at the front, is represented by the equivalent number of samples you could fit in it using smaller 5ml pottles.


Words by: Lisa Whitfield

So you have worked hard all season. It’s time to dry the cows off and celebrate with a few days off.

You have your list of cows sorted out, you have cell count records, you have done your dry cow consultation and have the products ready to go. Now to get the job done.

Having worked so hard to get to this point, you know you should clean the teats thoroughly before you dry her off. However, you just want to get the job done as quickly as you can, and you can’t be bothered with the hassle of cleaning the teats.

The cups have just come off, the teats are clean, right? Get the job done and let’s go home.

Wait a moment – you have put in hours of effort getting to this point in the season, and you have invested thousands of dollars in dry-off products, but you can’t be bothered to clean the teats before administering it?

There are three situations in which I regularly see hygiene being ignored when it comes to mastitis management.

Firstly, when administering products for drying off, secondly when taking milk samples for culture and finally, when administering mastitis treatments during lactation.

Hygiene and bacteria

In terms of the potential to permanently damage a cow’s lifetime production, or even result in her death, lack of hygiene at drying off is a really significant problem.

Teats which have just had the cups taken off, are not magically free of infectious agents.

A visually clean teat does not mean that there are no bacteria there. Unless you disinfect the teat end, bacteria will be present.

Unless you take care with where you hold the teat and how you handle the tubes, bacteria can easily be reintroduced even following disinfection.

In fact, if you take a swab of the end of the teat after cups off, you will grow a beautiful but nasty range of organisms, all of which can give a cow mastitis if you inoculate it into her udder using an intramammary tube.

Milk samples

Hygiene is also important when you are taking milk samples, however in this case you are wasting money if you do not put in the effort to do it correctly.

If you take a milk sample but do not disinfect the teat, you will contaminate your sample with dirt and bacteria from the teat end.

With milk sampling, you also must consider hygienic handling with the pottle and pottle lid – if the inside of either of these items become contaminated with bacteria, you ruin the milk sample and waste your money.

Did you know that for a milk sample, you only need a tiny amount of milk? In fact, less than 0.5ml is a sufficient sample to culture from.

The pottle into which you take your milk sample should reflect the size of the sample you are taking – you do not need an 80ml pottle for a 0.5ml sample.

Also, you do not need 80ml of milk for a milk culture. Ask for 5ml pottles and collect about 1cm of milk into it – less than one full strip of milk is all you need.

When you collect more milk than you need, you increase the risk of contaminating the sample – the less times you need to strip the teat the less chance of contamination falling into your pottle.

Intramammary tubes

Finally, intramammary tubes for mastitis treatment during lactation. It is a real hassle to have to get a wipe for the teat before you treat the cow with an intramammary mastitis treatment – when the pressure is on in the shed, it is the first thing that gets missed. I know this as I struggle with it myself.

However, the risk is no different to drying off. If you have bad luck and introduce bacteria into the udder when you administer a tube, you might just kill the cow.

The best way to make it easy for yourself is to keep a small pottle of methylated spirits-soaked cotton wool next to where you keep your mastitis tubes.

That way, if it’s there and ready to go, there really are no excuses for not using them.

  • Lisa Whitfield is a Manawatu-based production animal veterinarian with Lisa Whitfield Farm Vet Services.