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  • ZISK

Whose hay test is accurate?


Determining the quality of hay on a dairy farm can often seem like a “men are from Mars, women are from Venus” quandary. Why? Because the grower or hay broker emails their lab test to the dairyman and then the nutritionist shows up and samples the same lot of hay once it arrives on the farm. Most often he or she uses a different forage lab than the hay grower/broker. Sometimes the hay quality is very similar across the samples……often it is not. I work with a particular dairy farm where the hay broker’s samples routinely test in the 180+ RFQ (relative forage quality) range. My samples of the same hay typically test in the 140 RFQ area. What’s going on? He is sending his samples to a reputable lab, as am I……...just a different lab. I wonder if there could be subconscious bias. When he walks past a pile of hay to sample, is his probe drawn towards the nicest, leafiest looking bales, while I attempt to randomly sample the lot? Or, after checking multiple forage labs, has he found a lab that consistently leans toward overestimating hay quality? I’m not willing to accept his numbers because I have years of experience with the forage lab I use, and I know how their reports relate to cow performance. How can we meet in the middle? Have you ever run into this situation? These are my thoughts on fixing it…..I’d love to hear yours!



1. Only look at RFQ. RFV (relative forage value) does not include a test of how well the cow can digest the fiber, and therefore doesn’t relate to cow performance as well as RFQ does.

2. Only accept samples from reputable forage labs that you both agree on.

3. Are you going to use the hay broker’s sample, the nutritionist’s sample or an average of the two? Agree before you buy.

4. If there is a large difference between samples, have the hay broker and the nutritionist meet on the dairy, each sample the same 8 bales of hay and mail the samples to their respective labs.

5. MOST IMPORTANTLY….watch the cows! Their performance will tell you whether your samples are accurate or not.

6. And last….do a consistent job of sampling the hay that shows up on the farm. I can’t count the number of times I’ve been told that the hay a dairy is feeding is guaranteed to be 180+ only to see it test much lower. That costs you money and holds your cows back from maximum production. Get what you pay for!


Doc’s Ruminations

Insights from Dr. Kevin Hoogendoorn, DVM, Creator and Owner of the ZISK dairy app.

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