Managing hay resources: Evaluating hay for purchase

By Chanda Enge
SDSU Cow Calf Field Specialist
Watertown Regional Extension Center

Calving has begun or is not far off for many beef herd managers in the area. As winter progresses we are closer to spring and green grass, however, the hay pile may be shrinking faster than anticipated. This may bring about the need to purchase some additional hay stocks to tide the herd over until the grass is ready for them. Anytime we purchase hay we should give it two tests — one with our physical senses and one with a hay probe.

Sensory evaluation

The physical evaluation of hay, often referred to as a sensory evaluation, involves using both sight and smell. Visually inspect hay for stage of maturity, forage species, and any foreign matter. Odor can indicate heat damage (sweet tobacco or caramel like smell) and the presence of mold. Color is not a good measurement of quality, a sun bleached hay can still be higher quality than another hay that is bright green. Laboratory analysis of forage quality is the best and only accurate indication of how a hay will meet livestock nutrient needs.

Laboratory evaluation

Proper sampling technique is important in getting an accurate laboratory analysis result. Grab samples are highly inaccurate and frankly a waste of your time, effort and money. To get the best analysis, a hay probe with a sharp tip should be utilized to properly core and sample at least 20 bales within the same lot of hay. If you need help in finding a hay probe contact your local livestock extension professional. Both Near Infrared (NIRS) and wet chemistry are great analysis procedures, as long as a reputable forage lab is utilized. If you don’t currently have a laboratory you typically use, the National Forage Testing Association (NFTA; has a list of certified labs and the type of analysis they perform. The NFTA provides a grading system feedback, which helps indicate how well the lab has performed in analyzing a standard set of samples. Choosing a lab from the list that has a grade of A or B would be advisable. Most laboratories will provide you with free mailers and sample submission supplies, just contact them.

Additional fodder for thought

Purchase hay based on actual weight rather than per bale. There can be large variation in bale sizes and weights, particularly with round bale packages. Buying and selling on weight is a more equitable set of terms for both the buyer and seller.

Adjusting for moisture would also be beneficial as even a 2 percent difference in moisture can affect the cost. For example two lots of hay (Lot A and Lot B), each containing 100 round bales weighing 1200 pounds (lbs)/bale. Both lots weigh a total of 120,000 lbs (60 tons). Lot A is 90 percent Dry matter (DM) and Lot B is 88 percent DM. Lot A would be 54 tons of DM and 6 tons of water. Lot B would be ~53 tons of DM and 7 tons of water. A difference of one ton of DM between the two lots. If both lots were priced at $100 per ton, Lot B would actually cost you approximately $100 more than lot A. Or another way to look at it, you purchased an extra ton of water!

This makes me think of the time I was buying coffee. I could buy a 12-ounce Americano (Espresso + hot water) with two shots of espresso or a 20 ounce also with two shots — but the 20 ounce was a quarter more. I asked the barista, “So, let me get this straight. If I choose the 20 ounce, I am going to pay you 25 cents more to dilute my coffee?”

Her reply: “You’re a thinker.”

Hopefully, this will give you something worth ruminating on!