The Case for Hay Testing

One of my favorite activities as an Extension specialist is helping beef cattle producers put together nutritionally sound, cost-effective winter-feeding programs for cows and backgrounding calves.  Here in central Missouri, that almost always includes some level of hay feeding for part of the year.

Yet one of my biggest frustrations comes when asking a producer if they have had their hay tested.  The usual reply is something on the order of “No, but it’s average quality” or “I got it put up in pretty good shape without getting rained on”.  My favorite is “Well it doesn’t matter because that’s what they are going to get.”

Since the biggest factor impacting hay nutrient density is maturity at harvest, I’ll generally ask a follow up question along the lines of when was the hay put up and toss out a general time, such as mid-June, early-July, etc.  I’ll get some reply such as “Yea, about then” or “No it was a little earlier/later than that”.

All this to say that many times I do not get accurate information about the largest component of the winter diet of the cow herd which also makes up the largest portion of the annual production cost for the cow herd.  Armed with this lack of information, I try to make some educated guesses about forage quality and supplementation, but it is a somewhat meaningless exercise.  This uncertainty and confusion can all be avoided with a simple hay test.

To illustrate the variability of hay quality from year to year, I have summarized cool-season grass hay test results received in my office for the growing years 2015 through 2018 as shown in Table 1.  I haven’t gotten 2019 or 2020 summarized yet, but I’m sure the variability will be similar to that shown for the previous years.  The table shows the minimum, maximum and average values for crude protein (CP,%), acid detergent fiber (ADF,%), and total digestible nutrients (TDN,%) on a 100% dry matter basis.  Please take note of the minimum and maximum values both within years and between years.  “Average quality hay” becomes a pretty meaningless statement when compared to the upper and lower ranges seen in these hay test results.  And just because a producer sampled hay two or three years ago, doesn’t mean that reflects the quality of this year’s hay crop. The whole goal of forage testing is to find out where the nutritional holes are in the forage component of the diet, and to fill those holes in the most cost-effective manner.  For example, giving cows access to a protein tub when the hay supply has adequate CP but is low in TDN doesn’t provide the energy the cows need, and supplies an unneeded nutrient which adds unnecessary expense to the winter-feeding program.  Better to spend $15 to $30 upfront on a hay test and get competent nutritional help to balance diets based on animal needs than to needlessly spend money on feed products simply because that’s how it’s always been done.

There are excellent videos on line which demonstrate the proper way to collect forage samples.  Be sure to use a bale corer and sample an adequate number of bales in each lot of hay to get representative samples for sending to the lab.

Hay testing and ration balancing targets the appropriate quality hay and supplement to each group of animals being fed.  Ultimately, this helps producers manage feed costs, reduces unnecessary feed purchases, and improves the production and financial aspects of the beef production enterprise.  If you have questions on hay testing or utilizing hay test results, contact your local Extension office for assistance.

Gene Schmitz, MU Extension Field Specialist in Livestock

The Alliance for Grassland Renewal is a national organization focused on enhancing the appropriate adoption of novel endophyte tall fescue technology through education, incentives, self-regulation and promotion.  For more resources or to learn more about the Alliance for Grassland Renewal, go to

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