The Squeeze on Milk Quality
Gary W. Rogers
University of Tennessee

In the last couple of months, many dairy processing plants in Tennessee and plants in the surrounding states have made changes to their milk quality requirements for incoming raw milk. These changes in milk quality standards have been driven at least partly by demands from retailers and major food service companies. The retailers and large companies have placed pressure on the milk companies and cooperatives to produce a higher quality product with longer shelf life. Dean Foods, for example, has implemented some new requirements (on bacteria counts and milk temperature) at the processing plants that they control. For Dean Foods' plants, the new requirements are more restrictive than requirements in the past. In addition, Dean Foods' plants are allowed to implement more stringent requirements at the local or individual plant level. To this point, as far as I can figure out, only bacterial count requirements and milk cooling requirements have been changed at most plants. However, eventually we will likely see some changes in Somatic Cell Count (SCC) requirements and perhaps even some requirements for raw milk to be free from some specific bacteria. Any new SCC requirements will likely be retailer-driven, but the bottom line is that SCC limits for raw milk to be acceptable at many plants (if not all) may drop to levels much lower than they are now. As you might guess, these changes have made it difficult for companies like Dairy Farmers of America and Dairy Marketing Services to efficiently manage the milk supply. New SCC requirements would add more pressure to both marketing organizations and producers.

It is clear that dairy producers will be under more pressure to improve milk quality in the future. However, the more stringent requirements are not just the result of your marketing company deciding that they want to improve milk quality. These more stringent requirements for raw milk ultimately come from retailers and the major food service companies.

Below are some suggestions to reduce bacterial counts in raw milk. Implementing these changes will not have much impact on SCC. Bacterial counts and SCC are not very related and the same problems that cause high bacteria counts may not have anything to do with SCC. Reducing SCC requires other measures that will be addressed in a future newsletter. Work with your local milk company field representative to help with troubleshooting or to address any concerns. Contact UT dairy extension or your county extension office for more help.

1. Make sure that milk is cooled to 40° F or below (although not frozen) within 2 hours of milking and is maintained at this temperature until it gets to the dairy plant. Make sure that thermometers are working properly and make sure that fresh milk entering the bulk tank does not increase the temperature of milk already in the tank above 40° F. In some older barns with older equipment, it may be difficult to get to this standard, but every effort should be made to make this happen.

2. Make sure that teat ends are cleaned very well before milking machines are attached. Sediment on teats harbors bacteria that can cause high bacteria counts. Also, make sure that milking machines are not attached to udders that are wet because water running down the teats can get into teat cups and this water is laden with bacteria.

3. Make sure that the milking equipment is properly washed after each milking and properly sanitized before each milking. The use of hot water above 140° F in certain cleaning cycles is absolutely necessary. Make sure that the proper amount of cleaning solution or sanitizer is used every time. Make sure that filters are properly inserted and that they are free of sediment at the end of milking. If there is much sediment on the filter, you have a cleanliness problem in your milking routine. Periodically check milk lines and hoses to make sure that they are being properly cleaned and sanitized. Use new gaskets and hoses if they are deteriorated and cracked. Any milk contact surfaces should be completely free of deposits when dry. Check water used in milking-related tasks and properly treat the water if it has coliform bacteria or high bacteria counts.

4. Cleanliness in all phases of the milking routine is essential. Any exposure of the milk contact surfaces to water or anything other than milk can result in bacteria getting into the milk. Never let water or anything other than milk get into the milk lines after equipment has been sanitized.

5. A clean, dry environment for milking cows is very important. Maintaining milk with low bacteria counts starts with having clean cows and clean milking equipment.