Pre-milking teat disinfection
Pre-milking teat preparation is widely practiced in Europe and North America. In the US it is a requirement of the food safety legislation. In recent years pre-milking teat disinfection has become more widespread in Australian herds. The application of a teat disinfectant prior to milking may provide some extra control over environmental infections, especially in early lactation. If you are using, or are considering pre-milking teat disinfection there are a few issues that should be considered.The pre-milking protocols used by the Americans have names like " dip, strip, dry and apply" and the benefits of these protocols are not only due to the application of a disinfectant. The disinfectant solutions act primarily as cleaning agents with the bacteria and debris being removed when the solutions are wiped off prior to cup attachment. The stripping of the quarter permits the fore milk to be examined for evidence of mastitis and stimulates milk ejection, increasing milk flow rates and thereby reducing milking time. The removal of the disinfectant is important. It ensures the teats are clean and dry before the cups are applied, it further stimulates the ejection reflex and it prevents an inhibitory substance (the disinfectant) from contaminating the milk. The products used differ from products applied as post-milking disinfectants. It takes time and effort for the procedure to be done properly. The benefits of pre-milking teat preparation include fewer bacteria delivered into the milk, less bacteria around the teat end, quicker milking, and the identification of infected quarters. It is quite likely that the greatest benefits from pre-milking teat preparation are delivered by the improved milk let down leading to faster, cleaner milking, and the improved detection of clinical mastitis. Most farms in Victoria that employ pre-milking preparation simply spray on their normal teat disinfectant and then apply the cups. Some people are finding that their cell counts and the number of clinical cases have reduced following the adoption of pre-milking spraying. The negatives associated with the practice are numerous. For a start, there are no products in Australia registered for use as a pre-milking disinfectant, and this means that any use of a registered teat disinfectant is "off label". In short, we do not have guidelines for the practice. Secondly, by applying the cups to wet teats, the cups are likely to crawl up the teat reducing the quality of the milking. The presence of emollient in the mix acts as a lubricant and accentuates the cup crawl and may cause cup slip at the end of milking. The liner life may be altered because of exposure to the chemicals in the disinfectants. Finally, by failing to remove the disinfectant before application of the cups you ensure that an inhibitory substance enters the milk vat.
The benefits of pre-milking teat disinfection are greatest when applied to freshly calved cows, in early lactation or any other period when the teats are exposed to high levels of contamination. If iodine is being used it should be applied in a more dilute form than for post-milking disinfection. Emollients should not be added. Ideally, any disinfectant applied before milking is mixed separately from the post-milking product and is wiped off before the cups are applied.
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