Whether you're testing milk from an individual animal or a bulk tank, unlike other microbial tests, Delvotest® T ampoules are robustly designed to test both🔗. The challenge however is getting samples that properly represent the milk being tested. In this article, we explore some best practices and tips.
Individual Animals
Whenever an individual animal is treated with antibiotics, the prescribed drug(s) should come with specific advice on the correct withdrawal time to follow before the animal's milk can safely be added in the food chain. As withdrawal time is about how long it takes for antibiotics to 'clear out' of the cow's milk, it typically presumes that normal milk volumes are collected during treatment and the antibiotics are flushing out over time. First and foremost, it's very important to always follow the advised withdrawal time in full, where appropriate, carry out normal milking. However, treated cows may suffer from limited milk production during treatment or recurrent infections and relapse that requires additional time before the milk is free from unsafe antibiotic levels.
By following TETA ('Test Every Treated Animal')🔗, you ensure that the animal's milk can safely be added to the bulk tank.
But how do you safely collect a sample that properly represents the animal's milk you're about to test? Simple: just follow these five steps.
Step 1
It's very important to work in hygienic conditions to avoid contamination—and it's as equally important to make sure contamination does not come from your cleaning materials. So make sure not to use any disinfectants and/or cleaning agents, as they themselves can contaminate your sample for microbiological inhibition analysis tests like Delvotest®.
Step 2
Get a container that can hold a full milking from this animal, from all parts of the udder.
🐄 For cows, a c. 15-20 liter tank is typical per milking
🐐🐑 For goats and sheep, that's usually much lower, c. 2~3 litres.
Step 3
Using all teats, fully milk the animal. It's very important to not only milk from one or some teats, to ensure that the sample properly represents the entire milk supply. This helps get accurate antibiotic test results, as residue may not be evenly distributed in the udder.
Step 4
Mix the milk gently in the container, avoiding creating foam. This will help homogenise it, making sure the sample you'll be collecting is an accurate representation of the mix of things that are in it—like, potentially, antibiotic residues.
Step 5
Most likely, your Delvotest® set up might be in a different, more hygienic, controlled location in your farm from where you collected the milking. If this is the case, especially as carrying around a full 15-20 litre tank from a cow's milking can be inconvenient, take an intermediary sample into a smaller container (like a vial) using an appropriate sampling tool.
That's it, simple! By following the principles reflected in these steps you'll reduce costly risks from contamination and unrepresentative sampling in your efforts to TETA ('Test Every Treated Animal')🔗
Next Steps
Are you new to Delvotest® or simply looking for tips on how to get the most out of our products? Now that you know more about best practices for collecting milk for testing, you might want to read next about best practices for running a test—from properly acclimatising ampoules your Delvotest® T ampoules, to reading at Control Time, and more.
⏭️ Next article: Best Practices // Running a test🔗
💬 Got any questions? Need help? Contact us at support@delvotest.com