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.