Proper milk sampling is important to the accuracy of milk analysis results you get back from the lab.

"Sometimes we forget about the sampling part and how important that is," says Dave Barbano, food scientist and director of the Northeast Dairy Foods Research Center at Cornell University.

On-farm milk flow meters and proportionate samplers have replaced glass weigh jars as the sampling devices of choice on many of today's dairy operations. However, getting a representative milk sample is a concern when using these devices.

For example, an early-lactation cow milked 2X can fill the sampling container three times in one milking.

"If you don’t take it off and empty it, you just got a sample of the first third of what that cow produces," Barbano said during a presentation at the recent Tri-State Dairy Nutrition Conference. "That first third is very different composition than the last (third)."

If you collect only the first third of milk, it can lead to "totally erroneous results on that animal," Barbano said. It's not a good representative of what she is producing in terms of milk composition.

As a manager, look at what’s going on during milk sampling and ask questions.

"You need to pay attention to sampling," Barbano stressed, especially when it comes to early-lactation, high-producing cows.

“Cows are producing more milk per day, and we need to modernize equipment to deal with that and get good samples."