Who needs cow prep?

Jeffrey K. Reneau, Professor of Dairy Management

November 2, 2007

Pre-milking cow prep, who needs it? The simple answer to the question is YOU DO! Every dairy should optimize pre-milking cow prep to meet today’s milk quality standards. Optimal pre-milking cow prep contributes to increasing milk yield, lowering milking “machine-on” time, and improving udder health. However, these are not the main reasons that pre-milking cow prep will continue to be recommended in the future. High bacteria or SCC in milk reduces shelf life of pasteurized milk. Current shelf life concerns indicate that the main reason future dairies will optimize pre-milking cow prep is to satisfy processor needs and the consumer mandate for milk quality and safety. The pursuit of quality is a winner for everyone – the cow, the farm, the processor and the consumer. Cow health and productivity is maximized, dairy farm efficiency and profitability will be realized, processor product yield and quality is optimized, and consumer confidence and satisfaction is assured.

Milkers, compelled by the speed of pre-milking cow prep rather than thoroughness, often fail to achieve either adequate teat sanitation or consistent milk letdown stimulus. In herds where there is more than one milker, there is usually a great variation in milking routine. All of these factors can contribute to lower milk quality, yield and poor udder health as well as inefficient milking. Most important, remember that whatever bacteria are not removed from the teat surface before machine attachment will end up in the milk and may also create new mammary gland infections.

In the “real world,” nothing is perfect; there will be tradeoffs between what is optimal and practical. While there are basic scientific principles that govern what is acceptable cow prep procedure, there is no single procedure that fits all dairy farms. But if your milking routine includes the following 10 factors, you will be on your way to improving milk quality. Every pre-milking cow prep routine should:

• Minimize water use, and whatever water is used to clean teats or udder surfaces must be dried off before the milking machine is applied.
• Focus attention on teat surfaces. It is best to concentrate your cleaning effort on the teat surfaces only.
• Use a sanitizer (i.e. prep-dip) for pre-milking teat cleaning.
• Assure complete pre-dip coverage of teat surfaces. You should always cover the entire teat with sanitizer; otherwise it is difficult to kill many bacteria.
• Allow pre-dip 30 seconds contact time. Sanitizer does not kill bacteria instantly. Organize your milking routine to provide adequate contact time for bacteria to be killed by the pre-dip.
• Provide adequate pre-milking cow prep and milk let down stimulus (teat cleaning massage, fore-stripping, teat drying) for a minimum of 10 to 20 seconds. While milk letdown is important for achieving quick and complete milk out, taking the time to get teat surfaces clean and dry before milking machine application is even more important in achieving milk quality.
• Provide a prep-lag time of 60 to 90 seconds. Prep-lag time is the time between when teat surfaces are first massaged or fore-stripped until the milking machine is applied. Research indicates that this is the most important factor in achieving efficient milking and reducing machine-on time. Note: applying pre-dip without massage doesn’t count as a significant let down stimulus.
• Remove all dirt, manure and bacteria from teat surfaces. It cannot be over-emphasized; whatever bacteria we fail to remove before machine application will end up in the milk!
• Minimize machine-on time. Excellent and consistent cow prep and a disciplined prep-lag time will maximize milk flow rate; thus, minimizing machine-on time. Using ATO in parlors or an end of milking indicator in tie stall barns to avoid over-milking will reduce chances of inducing new infections. This results in improved teat condition and less teat end hyperkeratosis (callous).
• Minimize variation between milkers. Standardizing your milking routine between milkers will result in improved parlor throughput and/or lactation milk yield. Full lactation studies in Denmark have shown that application of a standardized milking routine resulted in a 5% increase in milk production. It seems to me this is a no-brainer. Optimize your pre-milking cow prep and get everyone to follow the same procedure and the cow wins, you win, the processor wins, and so do our dairy consumers.

You may be thinking, “Reneau, you’ve been preaching all of this for years. Isn’t there anything new?” Yes, there is new research data. During 2007, a group of lactation physiologists in Europe confirmed in very detailed studies that the above 10 factors for ideal cow prep are still true. Some things don’t change and the need for excellent pre-milking cow prep is one of those things. As milk quality demands continue to escalate, it is evident that you will need to use consistent and excellent pre-milking cow prep more than ever.