Allison Lund, Indiana Prairie Farmer, Senior Editor
(Previously published online with FarmProgress Indiana Prairie Farmer: June 14, 2024)
Get into 
the routine of sampling after every cutting. Here are tips for how to access a probe and how to take proper samples.
“I know my hay” is a common reason folks give for why they do not sample their hay. However, environmental factors can alter nutrient levels and create a scenario where what you think you have and what you do have for hay do not match.
A solid habit to form is sampling hay after each cutting, according to Nick Minton, beef systems specialist at Purdue. He echoes the sentiment that nobody can know the nutrient levels of their hay without testing.
“The most-skilled producer will look at a hayfield and say, ‘That’s going to be great hay,’” Minton says. “It can be a great-looking field of hay, but the only way we’re going to know if it’s low quality, moderate quality, or high quality is if we sample it and compare it to the thousands of samples that are in databases at commercial labs.”
How to sample
Minton says every producer should have access to a hay probe in some form, adding that only large hay producers need to buy one. Check with your county Extension office, local feed mill, or local agronomy service to see if they have one. If your county Extension does not have one, they should be able to acquire one from a neighboring county.
The type of bale you’re sampling determines what method to use. The key is to pull a representative sample that penetrates layers. For round bales, push the probe into the side of the bale. For squares, push the probe into the end of the bale.
You want to sample at least 10 bales from a field for a total of at least 20 cores. So, you can take two cores from each bale — one from each side or end — and combine them for a total sample. That sample should weigh about 1 pound, which is what most commercial labs need for testing.
After you’ve pulled your cores, put the sample into a Ziploc bag and push out as much air as possible. Minton says it is best to mail the sample that same day or put it in the freezer and mail it the next day. Additionally, he recommends mailing samples on a Monday or Tuesday.
When to sample
Minton says it is best to sample about a month before you plan to feed the hay. This will ensure that the nutritional value your livestock gets from the hay is as close as possible to what is reflected in the sample test results.
For baleage, sample two weeks before you feed it. Keep oxygen out after penetrating the bag by taping over the sample hole with repair tape for sileage bags or films.
While it may seem like overkill to sample after each cutting, Minton says this practice will give you the most accurate snapshot of your hay quality. The first cutting will typically be lower quality for most perennial forages, so it can be hard to predict what the quality will be after each cutting without sampling.
Routine sampling can also help producers pivot and change practices. For example, it may alter how you choose to store your hay to slow deterioration.
“Sampling after each cutting allows a producer to better outline and develop a strategy on which hay to feed first,” Minton adds.