Goat Milk Sample Collection - How It Works

OMAFRA understands the importance of a reliable goat milk sampling and testing program. The following article spells out exactly how the entire process works and the controls that are in place to make sure results are accurate - from the bulk tank to the laboratory.

Goat milk sample collection, transport, storage and testing all have the potential to affect quality results. That's why various checks and balances have been set up throughout the milk sampling system to ensure samples arrive at the laboratory in perfect condition.

Bulk Tank Milk Graders (BTMGs), more commonly referred to as " drivers", have been trained to collect milk samples that accurately represent what's in individual bulk tanks.

• BTMGs have been trained and certified for their duties associated with collection of milk at the farm including proper collection and storage of milk samples.
• Bulk tanks must be agitated for a minimum of five minutes prior to the sample collection
• Sterile, sealed, tamper-proof sample vials supplied by the University of Guelph's Laboratory Services Division (LSD) are used
• Individually wrapped sterile straws are used to fill sample vials. The supply of straws is kept clean and dry by the BTMG in order to prevent contaminating the sample.
• It is the producer's responsibility to provide a clean, long handled dipper if it is needed to reach the milk for sampling. Stainless steel or smooth plastic construction are preferred. Rough welds, wood and tape are not acceptable as they may contribute contamination to the sample. The dipper should be placed in a freshly prepared sanitizer solution and available to the BTMG on pickup day.
• If there happens to be a problem at the farm on collection day that will affect the sample e.g. agitator not working, dipper not available), the BTMG is still required to collect a sample. However, the BTMG will tag the sample to alert the lab that it is not representative of the milk in the tank and therefore should not be tested for composition or quality. If necessary, the sample will still be available for inhibitor testing and further grading.
• To maintain sample temperature between 1°C and 4°C, BTMGs are required to transport samples in coolers fitted with plastic inserts that are filled with an ice water mixture.
• A sample vial containing water is kept in the insert at all times so the BTMG can easily monitor the cooler temperature with a hand held thermometer.

At the Depot

Up until recently, BTMGs delivered bulk tank milk samples to one of more than 100 depot fridges located at various milk transporters and processing facilities across the province. These depot fridges are equipped with Time Temperature Recorders (TTRs) that provide a continuous recording of the internal temperature. From these depots, milk samples have been routinely collected and transported to Lab Services Division (LSD), University of Guelph by a refrigerated truck.

Alternatively, goat milk supplier groups have made arrangements to transport samples from depots to LSD via private courier services such that samples arrive more frequently for testing. To verify sample temperatures during their trip to the lab, BTMGs pack them in coolers equipped with "Red Flag" temperature recording devices which are activated by the BTMG to begin recording cooler temperatures once the samples leave the care of the BTMG. Sample coolers are stored in the depot until pick up by the courier. Once samples arrive at LSD temperature readings are downloaded and checked by lab technicians. Quality testing is not performed if the sample temperature was, at any time, over 4°C.

Time Temperature Recorders

Whether samples are transported from depots to LSD using the refrigerated truck, or by private courier service, sample storage temperatures are traceable and can be verified prior to testing. All depot fridges, sample transport trucks, and the refrigerators at LSD are equipped with temperature recording devices. The charts from these temperature recorders are reviewed. If temperature recording information is not available, or if there is any indication of temperature abuse, samples are not tested.

Testing by an accredited laboratory

LSD is an accredited lab, meaning that it must take extra steps to ensure the accuracy and repeatability of test results. Sample handling and test methods and procedures are documented and validated by trained and experienced technicians. If technicians have any reason to suspect that samples have not been stored at the proper temperature, they are not tested. Only goat milk samples that are one or two days old (from point of collection at the farm) can be tested at LSD. Samples older that two days are not tested.

The integrity of the goat milk sampling system rests in the hands of producers, BTMGs, temperature recording technology and qualified lab technicians. All are doing their part to ensure high-quality goat milk and fair compensation for producers.

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