How to select the best teat disinfectant for your herd

Teat disinfection is the cornerstone of producing high-quality, hygienic milk while helping to reduce new mastitis infection rates.

Ultimately, regardless of product choice, the only way to get the most from teat disinfection is to ensure you are applying it correctly to every cow at every milking.

“It’s that old adage that the best teat disinfectant is one that’s applied 365 days a year at every milking on all the teats of all the milking cows,” says vet Andrew Biggs of The Vale Vet Group.

There are a variety of product choices with varying disinfectant types, emollient levels and formulations. And although there’s no set answer as to the best type, there are a number of questions to ask when selecting a teat disinfectant to make sure you’re making the right choice for your herd.

Why use a teat disinfectant?

As dairy farmers producing a food product, ensuring parlour routine is up to scratch is key to getting the best returns from your milk. Teat preparation and disinfection helps remove soiling and bacteria and reduces mastitis risk, while promoting good teat condition and milk let-down.

Pre-milking disinfection is primarily targeted at reducing mastitis causing pathogens originating in the environment, for example, bedding, soil or manure. These bugs include Strep uberis or E coli.

Post-milking disinfectants are aimed at reducing contagious pathogens, such as Staph aureus and other persistent infections that are spread during milking.

It is worthwhile speaking to your vet and establishing the main causal pathogens on farm so management can be addressed accordingly. However, Mr Biggs believes all farms should be using a post-milking disinfectant.

“Just because you have environmental mastitis on farm doesn’t mean you shouldn’t bother with post-disinfection,” comments Mr Biggs.

And although there are many herds that do not disinfect pre-milking and still have good milk quality, Mr Biggs says application pre-milking still has an important role to play on most farms.

“Any farmer looking to produce quality milk, while reducing mastitis risk from environmental pathogens, should look at pre-milking disinfection,” he says.

Because pre- and post-milking disinfectants have varying roles they consequently need different considerations.

Choosing the right disinfectant

Pre-milking disinfectants

A pre-milking disinfectant is designed to only be on the teat for a short period before being wiped off prior to cluster attachment. Consequently, a fast acting disinfectant with a good wetting agent for good teat coverage is key.

Teat conditioners, known as emollient or humectants, are not needed in a pre-disinfectant because the product is only on the teat for a short period and emollients can compromise the efficacy of the disinfectant.

A pre-milking disinfectant should be left on the teat long enough for an effective kill and also to provide an ideal lag time of 60-90secs from initial teat stimulation to cluster attachment, says Mr Biggs. This will encourage optimum milk let-down.

Post-milking disinfectants

The disinfecting properties of post-milking disinfectants are designed to last between milkings. Because the product is on the teat for an extended period, emollient levels are also important to promote good teat condition.

When teat skin condition is an issue in your herd you may need a higher level of emollient in your post-disinfectant. However, when teats are dry and clean, high emollient levels may not be of such concern, says Mr Biggs.

“Decide what your main issue is on farm,” he says. “Is it transfer of bacteria or teat condition? Remember emollients compromise the efficacy of the disinfectant.”

Barrier dips

Some producers also use barrier dips post-milking. These create a protective film around the teats to improve condition and prevent contamination between milkings.

These are generally more expensive than straight post-dips so whether it is worthwhile will need to be established on a farm by farm basis.

Combined pre- and post-milking disinfectants

As herd size has increased and labour reduced, there has been greater demand for products that can be used both as a pre- and post-milking disinfectant.

These are designed to meet the demands of both a pre- and post- disinfectant. Both Mr Biggs and Ian Ohnstad from the Dairy Group, believe the nature of these products means there will always be a degree of compromise built in because the needs of a pre- and post-disinfectant are different.

Mr Ohnstad says: “If you have no major problem with mastitis, then a combined product is a good line of defence. However, if you have a problem, aim for a dedicated pre- and a dedicated post-milking disinfectant.”

Key areas for consideration when selecting a teat disinfectant:

Mr Ohnstad runs through the main areas for attention when selecting teat disinfectants:

1. Check for marketing authorisation

This will give confidence in the efficacy of the product. In a pre-disinfectant you need a good kill speed. When a label says the product has passed the EN1656 test this is a good start.

This assesses product kill speed (see “New disinfectant legislation” below).

Also check label wording. If it says the product is “an aid to reducing mastitis” it is making medicinal claims which must have data behind it to back this up. If a product says “helps clean teats” this is not claiming anything.

2. Emollient levels

Emollients have an important role in post-milking disinfectants, but again, check the wording.

There are three types of emollient: glycerine, lanoline and sorbitol. Glycerine is the most effective, but also the most expensive. A label may say “10% emollients” but what does this mean? Ask the manufacturer for the datasheet to see exactly what’s in it.

Always ask what you are trying to achieve. If your herd has good teat condition, sorbitol and lanoline in a post-disinfectant would be OK. But, if your cows have very dry teats, look for a high glycerine product to improve condition.

For traditionally formulated teat disinfectants, a post-disinfectant with less than 10% emollients can be seen as a good all round post-milking product, but not in the top range.

Over 10% emollient levels will promote good teat condition. However be aware this is different for newly formulated iodine teat disinfectants.

These new formulations are less acidic and can include lower iodine levels and lower emollients and still be as effective.

3. Disinfectants

There are a number of disinfectants available. The best way to ensure you have an effective product is to check product labelling for claims about efficacy. You can’t specify an ideal disinfectant level as products vary.

4. Licensed products

At the moment not all teat disinfectant products need to be licensed (see “New disinfectant legislation” below). If a product has a VM number, this shows it is licensed.

New Disinfectant Legislation

Most disinfectants don’t have to be licensed. But new EU rules mean all disinfectants will have to be licensed in the future, explains Alison Cox from hygiene product specialists Diversey.

“This will give farmers the confidence product they’re buying has been through testing and does what it says it does,” she says.

Many manufacturers will reference the EN1656 test for pre-milking disinfectants. This looks at the efficacy of the disinfectant at killing bacteria.

To have passed the test, the product would have achieved a 99.999% kill in five minutes. Any company saying its product has a 15-30sec kill has done an accelerated test.

“In the future, any company saying their product has a 15sec kill would have to have this backed up by independent testing,” explains Ms Cox.

Dos and don’ts

  • Do
  • Investigate where the main mastitis issues are on farm – speak to your vet
  • Address the cause of mastitis or teat contamination on farm
  • Buy teat disinfectants from a reputable company and ensure products have a label and market authorisation information
  • Cover every teat of every cow at every milking
  • Only wipe pre-milking disinfectants off just before cluster attachment and ensure a lag time of 60-90secs from initial stimulation to attachment
  • When spraying, apply using a figure of eight pattern, to ensure maximum teat coverageFollow manufacturer’s mixing instructions carefully
  • When mixing your own disinfectant only use clean water as any organic material will reduce efficacy (when using own farm water supply, get water tested)
  • Don’t
  • Use a post- disinfectant as a pre- disinfectant
  • Store products in sunlight or freezing conditions – ensure they are protected from the elements
  • Apply post sprays as cows walk out of the parlour in a herringbone system as it’s likely teats will be missed
Pros and Cons of different teat disinfectant application methods  
 Pros  Cons
 Uses less product than spraying*  Repetitive strain from squeezing dip cup can be issue
 Harder to use incorrectly than spraying   Takes longer
 Gives good teat coverage   Increased risk to operator from cow kicking during application
   Cups need to be cleaned and re-filled after every milking
 Ease of application  Uses more product than dipping (Can be up to 50% more)
   Needs close attention to ensure accuracy of application
   May need maintenance or nozzles replaced
 Foam dip
 Good wetting ability  Not all products can be used as a foam – check with the manufacturer
 Uses less product than spraying or dipping  Specialist foam cup is needed
Automated teat spray 
 Reduced labour   Can miss cows particularly on exit races
 Can work well in rotaries and robot milkers  
  *Typically 10ml a cow for dipping and 15ml a cow for spraying