Dairy farmers are paid for their milk based on volume and quality, which is measured by fat, protein, somatic cell count (SCC), and bacteria presence. When the milk is picked up by the milk truck, a sample is taken from the farm’s bulk tank. These samples are then sent to a lab, like the Dairy One Milk Laboratory. The Dairy One Milk Laboratory is responsible not only for testing the DHI milk samples sent in by Dairy One Customers, but they are also responsible for testing a large number of payment samples collected at the time milk is picked up from farms across the Northeast. The farm’s bulk tank sample is tested for fat, protein, and quality as previously mentioned. These tests are required by state and federal regulations. This includes the Grade “A” Pasteurized Milk Ordinance (PMO), a set of standards established by the FDA, that ensures milk quality. Before milk can be processed and put on retail shelves, there are a variety of regulatory tests that occur outside of butterfat and protein analysis to ensure proper food safety.
There are two types of bacteria testing that are typically used for milk analysis. The first type of test is a standard plate count (SPC) test. This test is a measure of cleanliness of the farm and its milking procedures. Bacteria found by an SPC can be caused by things such as poor teat cleanliness or poor milking system sanitation. The PMO requires this type of test on a monthly basis. There is a maximum limit the PMO allows for this bacteria count, but most milk companies choose to set this standard far lower in order to provide higher quality milk which may warrant a premium for farmers.
While the SPC is a test that is done on cold milk, the preliminary incubation count (PI) is a test that is performed on milk that is heated to 55 degrees Fahrenheit for 18 hours. After the milk has been heated for 18 hours, another bacteria count is taken to see what environmental bacteria may be present that were not exposed when the milk was chilled. It is important that SPC is performed before a PI so results can be compared. A contamination issue is typically found when the bacteria count of the PI is 3-4 times higher than the SPC count.
The Dairy One Milk Laboratory has the ability to perform a comprehensive set of tests for FDA approved antibiotics, which are performed randomly as an additional food safety precaution. However, all milk is tested at the plant when it arrives for processing. In the case that a test performed at the plant comes back positive for antibiotic or bacteria contamination, the Dairy One Milk Laboratory is one of the labs that could, and often does, perform traceback testing. The source of contamination can be traced back to the responsible farm using the bulk tank samples taken at the time the milk was picked up at the farm. The farm whose individual bulk tank sample comes back positive will be financially responsible for the entire truck load of milk, as the milk must be dumped.
Caitlin and Meghan, who work in the Dairy One Milk Laboratory, specifically in the Producer Payment lab, took me on a path of a bulk tank sample when it arrives at the lab for testing. When samples arrive at the lab they are put into coolers where they wait to be scanned in, or essentially “admitted” to the lab. Each sample is scanned and entered into the system. Once samples are scanned, they are sorted by the type of testing that needs to be done. Samples requiring just component testing (fat, protein, SCC) are put into one cooler and samples requiring bacteria and antibiotic testing are put in other coolers.
Additionally, The Dairy One Milk Laboratory is recognized and approved by the AOAC Research Institute and FDA as an independent reference laboratory, allowing the lab to provide finished product testing for a variety of dairy products you consume on a regular basis, such as heavy cream, ice cream, yogurt, frozen dessert products, and some butter and cheese. In order to maintain this approval, monthly inspections are performed by the New York State Department of Agriculture & Markets to ensure the lab is finding accurate measures of fat and protein. Additionally, the USDA performs semi-annual lab inspections to ensure lab equipment and processes are being performed correctly. Dairy One’s Check Mark Laboratory offers additional wet chemistry (this is the type of “classical” chemistry that involves beakers and flasks) testing for components such as fat, protein, total solids, casein, and lactose to further analysis product quality.
If you have ever visited Dairy One in Ithaca, you may have accidently found yourself at the Dairy One Milk Laboratory. While most of the services offered at Dairy One are housed at the 730 Warren Rd address, the Milk Laboratory and its services are housed one door down at 720 Warren Rd. This building is a little easier to spot as it is only a few years old and has a brand-new fancy sign. For this reason, many folks end up at that building by mistake when trying to reach the other building. If this has ever happened to you, find comfort in the fact that you are not alone (I did it myself the first time I visited the center).
Similar to some of the other groups we have heard about at Dairy One, the staff in the bacteria lab come to work with a diverse set of experiences and backgrounds. Caitlin, pictured scanning in milk samples, does not have an agriculture background but has been working at Dairy One for 5 years. She began working part-time in the DHI testing portion of the milk lab and has moved her way into her current position working in the bacteria lab. Meghan, who also showed me around the lab, has been with Dairy One for about a year. She does have a background in agriculture and holds a B.S. in Animal Science from SUNY Cobleskill. Prior to Dairy One she had worked in a few different lab settings, holding positions such as Quality Assurance Manager. Chuck, pictured above, made sure that I did not get lost in a maze of milk samples while I was visiting the lab. He has been with Dairy One for a long time. As Janice Root, the Bacteria Lab Manager would tell you, “he’s been here longer than the cows”. Chuck also has an agriculture background and graduated from SUNY Morrisville. These are just a few of the many friendly faces who work hard to assure the quality and safety of your milk, and who you might bump into if you ever find yourself at 720 Warren Rd (whether on purpose or by accident),