Farm Ireland

Saturday 24 March 2018

Stay teat dipping through summer

It's surprising the number of dairy farmers who don't teat-dip their cows during the summer months. In my naivety, I thought it was a practice that all 'good' dairy farmers did this without question.

But if you ask any discussion group of say 15 farmers, you will find two or three farmers stop post-milking teat disinfection of cows once the warm dry days of summer arrive.

I suppose they view it as one job less to do in the parlour and as a result the milking is speeded up. Obviously, they have been getting away with it as somatic cell count (SCC) has remained stable.

I don't believe the reason for giving up the practice is one of cost, since teat disinfection is not a major cost on a dairy farm. But there is a risk there, and I don't know if farmers who are not carrying out the practice know the risks they are exposing their herds to.

Why apply teat disinfectant to dairy cows once you remove the cluster? The answer lies in the fact that cows are more susceptible to picking up new infections in the half-hour after milking than at any other time during the day. This is due to the fact that the muscle at the tip of the cow's teat is relaxed after milking due to the impact of vacuum and pulsation during the milking process.

The teat canal is now open and there is a real possibility that bacteria, present on the teat, will gain access to the teat canal. If that happens, there is a real risk of these bacteria setting up a new infection as they move up through the teat and into the body of the udder itself.

The real danger here is when a cluster is removed from a cow with an infected quarter. Studies have shown that these bacteria are now spread to the next five or six cows milked with that cluster.

Fine if you are cluster clipping, you have now broken the cycle, but if you are not, bacteria will remain on the inside of the liner in their millions. Putting this liner up on the teat of the next cow is exposing her to a serious challenge, one that she will cope with or not, depending on what you do once the cluster is removed. Using a teat-dip and disinfecting the whole of the teat surface that is touched by the cluster liner will kill any bacteria present on the teat and greatly reduce the spread of infection.

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In fact, research shows that teat disinfection after milking reduces new infections due to contagious mastitis (eg infection with bacteria such as Staph aureus) by 50pc and is also important in reducing Strep Uberis (mastitis) infection.

Post-milking teat disinfection is one of the most effective SCC and mastitis-control measures available, but it only works if it is done thoroughly. Teat disinfection also helps to keep teat skin supple and healthy.

Failure to cover the whole teat of every cow at every milking throughout the year is the most common error in teat disinfection.

So, how much teat-dip per cow should you be using? The recommended amount is 15ml per cow per milking (when using a spray). That's 30ml per cow per day. In a 100-cow herd, that's 3,000mls of teat dip or three litres per day. Are you using that amount?

If you are using a dip rather than a teat sprayer, the recommended amount is 10ml per cow per milking. That's two litres of prepared dip in a 100 cow herd. With the amount of dip recommended above, a drop of teat disinfectant should be seen at the end of the cow's teat after dipping or spraying.

If you are using a spray, spray from beneath the teats, not from the side, and do not spray cows as they walk past. Dipping is more reliable than spraying for getting complete coverage.

One should also check the 'far sides' of teats of at least some cows to ensure they are being covered. Also, if you are using a dip cup, make sure to clean it out at least once per day.

So, what's the cost of teat-dipping cows using 15ml per cow per milking? I got a quote from a local creamery and I was asked for €60 for a top of the range, well recognised, ready to use teat dip in 20-litre drums.

Taking the example of 100 cows, needing three litres per day of dip, the 20 litres will be gone in a week. That's a cost of 8.5c per cow per day (€24 per cow in a 280-day lactation). That's a small price to pay, if it reduces new infection rates by 50pc.

Good teat dips should contain teat skin conditioners such as glycerine/lanolin/glycan, sorbitol and lanolinated esters. Such products greatly help to maintain skin condition.

John Donworth is a Teagasc dairy specialist based in Kilmallock, Co Limerick. Phone: 063 98049.

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