The International Dairy Federation has issued guidelines for interpreting results from testing milk for bacterial counts using different mathematical formulas.
The federation said most routine analysis is carried out with automated flow cytometry-based technologies and provide a total bacteria count, with conversion equations of instruments’ units to units of the classic Anchor method (Standard Plate Count) developed over the years.
However, it said conversion equations can vary considerably across countries or between laboratories.
This can cause problems in the international trade of dairy products as well as challenges within the relationships between international dairy companies, it said.
“This guidance document is a must-read for all those evaluating total bacteria counts and especially those organizing and using bacteria testing schemes such as regulators, milk producers, farm advisors, supply chain managers and purchasers of quality dairy products.
That would include Dairy Farmers of Ontario which the Ontario government has made responsible for testing milk quality.
