Pasteurizer Quality Control Sampling

 

This document will assist in testing milk or colostrum to be certain that the equipment is functioning properly and destroying all of the targeted pathogens in the milk.

 

WHEN TO SAMPLE:

 

  • Once the equipment is installed and operational, sample the milk or colostrum right away to help detect any deficiencies in milk handling or equipment function.

  • Sample the milk every month to stay on top of changing conditions or malfunctions that might otherwise go unnoticed

  • Any unexplained scours or calf illness should prompt a test of the system.

 

WHAT SAMPLES TO TAKE


  1. Sample the milk just prior to starting pasteurization.
    High counts here will tell us that the milk needs to be pasteurized sooner, or is being handled poorly as it gets to the pasteurizer. Milk can also be contaminated beyond a point that pasteurization can clean up which is another good reason to sample at this stage.

  2. Sample immediately following cool down of the product.
    If we have reasonable starting counts, elevated counts here will tell us to check temperature and time settings on the equipment.

  3. Sample the milk as it is being fed to the calves.
    a. This check point will help to see how well the product is stored and being handled after pasteurization … especially important sample to take if the calves are having a problem.

 

 

HOW TO TAKE THE SAMPLES


  • Take the samples early in the week to avoid weekend shipping issues.

  • Wear nitrile or latex gloves to reduce the chance of contaminating the sample with bacteria on your skin.

  • With a new 20cc syringe, submerge the tip 2-3” into the milk or colostrum and withdraw a sample. Your veterinarian may also offer other aseptic techniques for obtaining a sample. It is critical that the sample does not become contaminated during collection to have a true evaluation of the system.

  • Squirt the sample into the provided milk vial and identify the date and sample name (i.e. “prepast, postpast, or prefeed”) on the vial with a marker.

  • Refrigerate the sample immediately.

 

 

HOW TO SHIP THE SAMPLES

  1. Place the refrigerated samples into a small zip lock bag, then place them between two frozen cold packs in the provided cooler.

  2. Include your information with the samples and be sure to provide a fax number or email address so we can report back to you in a timely manner.

  3. Tape the box closed and place the provided shipping label on top of the box and ship next day/ overnight to:

 

The Dairy Authority
8215 W 20th St. Unit A
Greeley, CO 80634
970-351-8102

 

HOW TO INTERPRET THE RESULTS


Pasteurization is not sterilization, so there will likely always be some level of bacteria growing in the samples. The goal of pasteurization is to kill all these target pathogens:

• Mycobacterium avium subsp. Paratuberculosis
• Mycoplasma spp.
• Salmonella spp.
• Listeria monocytogenes
• Escherichia coli
• Campylobacter spp.
• Staphylococcus aureus

 

 

Many environmental bacteria such as coliforms and staphylococcus spp can survive the process. This is normal. The bacteria will grow colonies in the lab which will be reported back as a Standard Plate Count. This SPC number should be <10,000 cfu/ml.

 

If the results report back higher than this standard, we will want to assist you in performing a complete analysis of our equipment and your standard operating procedures for milk handling, storage, cleaning and calf feeding.

 

Standard Time/Temperature Combinations

Colostrum 140°F (60°C) 60 minutes
Milk LTLT 145°F (63°C) 30 minutes
Milk HTST 161°F 30 seconds