Farmers dedicate significant time to keeping cows dry, udders healthy, and teats clean. On the surface, pre and post dips are mechanisms to remove bacteria and organic contaminants before the milking cluster is applied. A properly executed pre and post-dip will help protect the cow from a mastitis infection from bacteria like S. aureus. When proper technique is consistent for every cow that enters the parlor, the overall herd somatic cell counts will go down, and the farm’s milk quality will go up. Proper hygiene is more than just a task in the parlor – proper milking procedures could save lives.
What is not fully understood is that while S. aureus has a detrimental effect on the health of cows and productivity, the presence of another bacterium, Listeria monocytogenes, can lead to deadly consequences. Listeria is naturally occurring on farms. In fact, dairy farms act as reservoirs for Listeria. It is frequently found in bulk tank milk samples and the feces of clinically healthy cows.
Listeria monocytogenes is a Gram-positive non-spore-forming bacterium which has an amazing ability to survive in harsh environments. Listeria can grow in temperature ranges of 1-45O Celsius, pH of 4.5-9.6, 25.5% salt concentration, with or without available oxygen. To make matters worse, it is the causal agent of Listeriosis which has a 20-30% mortality rate if consumed by humans. The mortality rate can reach as high as 70% of it goes untreated and infiltrates the nervous system.
Given the real possibility of health complications and even death from consumption of Listeria, the importance of mitigation through proper teat hygiene cannot be overstated. The proper technique for a pre and post-dip is as follows:
1: With a single use towel, wipe away all visual organic matter from the teat.
2. Teats must be entirely submerged in solution or covered with sanitizing foam.
3. Teats must remain in contact with the solution for at least 30 seconds or as per the manufacturer’s instructions.
4. Teats must be thoroughly wiped to remove the solution. For best cleaning action, teats should be wiped in a circular motion with attention paid to teat ends. Wiping stimulates milk let-down and reduces the risk of contamination up, into the teat end.
Proper Post Dip:
1. Disinfectant must be applied as soon as possible after removing the milking cluster.
2. Disinfectant must coat the entire surface that was covered by the teat liner.
3. Do not wipe disinfectant. In frigid weather, remove the excess sanitizer from the end of the teat to prevent freezing.
4. Products should be antimicrobial to eliminate bacteria with a skin conditioner since sores can lead to infection.
To verify teat sanitation and overall milking procedure hygiene, aseptically pen/string sample every group into a sterile collection unit and send the samples to a verified lab. Request species-specific results for staph, strep, coliforms, and pathogens like Listeria. A structured sampling program is the key to verifying on-farm milking procedures are being performed correctly and will identify possible issues before the herd is contaminated. When used as part of a Mastitis Control Plan, farmers can also proactively impact their quality premium and ensure they get paid top dollar for the milk they produce.
Proper hygiene is more than just a task in the parlor. It can literally save lives. Train your staff with the knowledge they need to mitigate this possibility.